Datasheet TNY288KG Specification

TNY284-290
TinySwitch-4 Family

™

Energy-Efcient, Off-Line Switcher With
Line Compensated Overload Power

Product Highlights

Lowest System Cost with Enhanced Flexibility

• 725 V rated MOSFET

• Increases BV de-rating margin

• Line compensated overload power – no additional components

• Dramatically reduces max overload variation over universal

input voltage range

• ±5% turn on UV threshold: line voltage sense with single

external resistor

• Simple ON/OFF control, no loop compensation needed

• Selectable current limit through BP/M capacitor value

• Higher current limit extends peak power or, in open frame

+

Wide-Range

High-Voltage

DC Input

TinySwitch-4

Figure 1. Typical Standby Application.

D

EN/UV

BP/M

S

applications, maximum continuous power

• Lower current limit improves efficiency in enclosed

adapters/chargers

• Allows optimum TinySwitch-4 choice by swapping devices

with no other circuit redesign

• Tight I

• ON-time extension – extends low-line regulation range/hold-up

2

f parameter tolerance reduces system cost

• Maximizes MOSFET and magnetics utilization

Figure 2. Package Options.

eSOP-12B (K Package) DIP-8C (P Package) SO-8C (D Package)

time to reduce input bulk capacitance

• Self-biased: no bias winding or bias components

• Frequency jittering reduces EMI filter costs

• Pin-out simplifies heat sinking to the PCB

• SOURCE pins are electrically quiet for low EMII

Enhanced Safety and Reliability Features

• Accurate hysteretic thermal shutdown protection with auto-

matic recovery eliminates need for manual reset

• Auto-restart delivers <3% of maximum power in short-circuit

and open loop fault conditions

• Output overvoltage shutdown with optional Zener

• Fast AC reset with optional UV external resistor

• Very low component count enhances reliability and enables

single-sided printed circuit board layout

• High bandwidth provides fast turn-on with no overshoot and

excellent transient load response

• Extended creepage between DRAIN and all other pins improves

field reliability

EcoSmart™– Extremely Energy Efficient

• Easily meets all global energy efficiency regulations

• No-load <30 mW with bias winding, <150 mW at 265 VAC

without bias winding

• ON/OFF control provides constant efficiency down to very light

loads – ideal for mandatory CEC regulations and EuP standby
requirements

Applications

• PC Standby and other auxiliary supplies

• DVD/PVR and other low power set top decoders

• Supplies for appliances, industrial systems, metering, etc

• Chargers/adapters for cell/cordless phones, PDAs, digital

Output Power Table

230 VAC ± 15% 85-265 VAC

Product

3

Adapter

TNY284P/D/K 6 W 11 W 5 W 8.5 W

TNY285P/D 8.5 W 15 W 6 W 11.5 W

TNY285K 11 W 15 W 7.5 W 11.5 W

TNY286P/D 10 W 19 W 7 W 15 W

TNY286K 13.5 W 19 W 9.5 W 15 W

TNY287D 11.5 W 23.5 W 7 W 18 W

TNY287P 13 W 23.5 W 8 W 18 W

TNY287K 18 W 23.5 W 11 W 16 W

TNY288P 16 W 28 W 10 W 21.5 W

TNY288K 23 W 28 W 14.5 W 21.5 W

TNY289P 18 W 32 W 12 W 25 W

TNY289K 25 W 32 W 17 W 25 W

TNY290P 20 W 36.5 W 14 W 28.5 W

TNY290K 28 W 36.5 W 20 W 28.5 W

Table 1. Output Power Table.

Notes:

1. Minimum continuous power in a typical non-ventilated enclosed adapter
measured at +50 °C ambient. Use of an external heat sink will increase power
capability.

2. Minimum peak power capability in any design or minimum continuous power in
an open frame design (see Key Applications Considerations).

3. Packages: D: SO-8C, P: DIP-8C, K: eSOP-12B. See Part Ordering Information.

1

Peak or

Open

Frame

2

Adapter

cameras, MP3/portable audio, shavers, etc.

www.powerint.com September 2012

+

DC

Output

PI-6578-101411

Peak or

1

Open

Frame

2

TNY284-290

PI-6639-113011

CLOCK

OSCILLATOR

5.85 V

4.9 V

SOURCE

(S)

SRQ

DC

MAX

BYPASS/

MULTI-FUNCTION

(BP/M)

+

-

V

I

LIMIT

FAULT

PRESENT

CURRENT LIMIT
COMPARATOR

ENABLE

LEADING

EDGE

BLANKING

THERMAL

SHUTDOWN

+

-

DRAIN

(D)

REGULATOR

5.85 V

BYPASS PIN
UNDER-VOLTAGE

1.0 V + V

T

ENABLE/

UNDER-

VOLTAGE

(EN/UV)

Q

115 μA 25 μA

LINE UNDER-VOLTAGE

RESET

AUTO­RESTART
COUNTER

JITTER

1.0 V

6.4 V

BYPASS

CAPACITOR

SELECT AND

CURRENT

LIMIT STATE

MACHINE

OVP

LATCH

LINE

COMPENSATION

PI-6577-053112

P Package (DIP-8C)

12 S

11 S

10 S

9 S

8 S

7 S

EN/UV 1

BP/M 2

N/C 3

N/C 4

D 6

K Package

(eSOP-12B)

Exposed Pad (On Bottom)
Internally Connected to
SOURCE Pin

D Package (SO-8C)

EN/UV 1

BP/M 2

D 4

8 S

7 S

6 S

5 S

5 S

7 S

8 S

D 4

BP/M 2

EN/UV 1

6 S

Figure 3. Functional Block Diagram.

Pin Functional Description

DRAIN (D) Pin:

This pin is the power MOSFET drain connection. It provides
internal operating current for both start-up and steady-state
operation.

BYPASS/MULTI-FUNCTION (BP/M) Pin:

This pin has multiple functions:

• It is the connection point for an external bypass capacitor for

the internally generated 5.85 V supply.

• It is a mode selector for the current limit value, depending on

the value of the capacitance added. Use of a 0.1 μF capaci­tor results in the standard current limit value. Use of a 1 μF
capacitor results in the current limit being reduced to that of
the next smaller device size. Use of a 10 μF capacitor results
in the current limit being increased to that of the next larger
device size for TNY285-290.

• It provides a shutdown function. When the current into the

bypass pin exceeds ISD, the device latches off until the BP/M
voltage drops below 4.9 V, during a power-down or, when the
UV function is employed with external resistors connected to
the BP/UV pin, by taking the UV/EN pin current below IUV
minus the reset hysteresis (Typ. 18.75 μA). This can be used

2

Rev. A 09/12

Figure 4. Pin Configuration.

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TNY284-290

600

to provide an output overvoltage function with a Zener
connected from the BYPASS/MULTI-FUNCTIONAL pin to a
bias winding supply.

ENABLE/UNDERVOLTAGE (EN/UV) Pin:

This pin has dual functions: enable input and line undervoltage
sense. During normal operation, switching of the power
MOSFET is controlled by this pin. MOSFET switching is
terminated when a current greater than a threshold current is
drawn from this pin. Switching resumes when the current being
pulled from the pin drops to less than a threshold current. A
modulation of the threshold current reduces group pulsing. The
threshold current is between 75 μA and 115 μA.

The ENABLE/UNDERVOLTAGE pin also senses line
undervoltage conditions through an external resistor connected
to the DC line voltage. If there is no external resistor connected
to this pin, TinySwitch-4 detects its absence and disables the
line undervoltage function.

SOURCE (S) Pin:

This pin is internally connected to the output MOSFET source
for high-voltage power return and control circuit common.

TinySwitch-4 Functional Description

TinySwitch-4 combines a high-voltage power MOSFET switch
with a power supply controller in one device. Unlike conventional
PWM (pulse width modulator) controllers, it uses a simple
ON/OFF control to regulate the output voltage.

The controller consists of an oscillator, enable circuit (sense and
logic), current limit state machine, 5.85 V regulator, BYPASS/
MULTI-FUNCTION pin undervoltage, overvoltage circuit, and
current limit selection circuitry, over-temperature protection,
current limit circuit, leading edge blanking, and a 725 V power
MOSFET. TinySwitch-4 incorporates additional circuitry for line
undervoltage sense, auto-restart, adaptive switching cycle
on-time extension, and frequency jitter. Figure 3 shows the
functional block diagram with the most important features.

500

V

400

300

200

100

0

0510

Figure 5. Frequency Jitter.

DRAIN

136 kHz

128 kHz

Time (µs)

Oscillator

The typical oscillator frequency is internally set to an average of
132 kHz. Two signals are generated from the oscillator: the
maximum duty cycle signal (DC

) and the clock signal that

MAX

indicates the beginning of each cycle.

The oscillator incorporates circuitry that introduces a small
amount of frequency jitter, typically 8 kHz peak-to-peak, to
minimize EMI emission. The modulation rate of the frequency
jitter is set to 1 kHz to optimize EMI reduction for both average
and quasi-peak emissions. The frequency jitter should be
measured with the oscilloscope triggered at the falling edge of
the DRAIN waveform. The waveform in Figure 5 illustrates the
frequency jitter.

Enable Input and Current Limit State Machine

The enable input circuit at the ENABLE/UNDERVOLTAGE pin
consists of a low impedance source follower output set at 1.2 V.
The current through the source follower is limited to 115 μA.
When the current out of this pin exceeds the threshold current,
a low logic level (disable) is generated at the output of the
enable circuit, until the current out of this pin is reduced to less
than the threshold current. This enable circuit output is
sampled at the beginning of each cycle on the rising edge of the
clock signal. If high, the power MOSFET is turned on for that
cycle (enabled). If low, the power MOSFET remains off
(disabled). Since the sampling is done only at the beginning of
each cycle, subsequent changes in the ENABLE/UNDER­VOLTAGE pin voltage or current during the remainder of the
cycle are ignored.

The current limit state machine reduces the current limit by
discrete amounts at light loads when TinySwitch-4 is likely to
switch in the audible frequency range. The lower current limit
raises the effective switching frequency above the audio range
and reduces the transformer flux density, including the
associated audible noise. The state machine monitors the
sequence of enable events to determine the load condition and
adjusts the current limit level accordingly in discrete amounts.

Under most operating conditions (except when close to
no-load), the low impedance of the source follower keeps the
voltage on the ENABLE/UNDERVOLTAGE pin from going much
below 1.2 V in the disabled state. This improves the response
time of the optocoupler that is usually connected to this pin.

PI-2741-041901

5.85 V Regulator and 6.4 V Shunt Voltage Clamp

The 5.85 V regulator charges the bypass capacitor connected
to the BYPASS pin to 5.85 V by drawing a current from the
voltage on the DRAIN pin whenever the MOSFET is off. The
BYPASS/MULTI-FUNCTION pin is the internal supply voltage
node. When the MOSFET is on, the device operates from the
energy stored in the bypass capacitor. Extremely low power
consumption of the internal circuitry allows TinySwitch-4 to
operate continuously from current it takes from the DRAIN pin.
A bypass capacitor value of 0.1 μF is sufficient for both high
frequency decoupling and energy storage.

In addition, there is a 6.4 V shunt regulator clamping the
BYPASS/MULTI-FUNCTION pin at 6.4 V when current is
provided to the BYPASS/MULTI-FUNCTION pin through an

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3

Rev. A 09/12

TNY284-290

PI-4098-082305

0

2500 5000

Time (ms)

0

5

0

10

100

200

300

V

DRAIN

V

DC-OUTPUT

external resistor. This facilitates powering of TinySwitch-4
externally through a bias winding to decrease the no-load
consumption to well below 50 mW.

BYPASS/MULTI-FUNCTION Pin Undervoltage

The BYPASS/MULTI-FUNCTION pin undervoltage circuitry
disables the power MOSFET when the BYPASS/MULTI­FUNCTION pin voltage drops below 4.9 V in steady state
operation. Once the BYPASS/MULTI-FUNCTION pin voltage
drops below 4.9 V in steady state operation, it must rise back to

5.85 V to enable (turn-on) the power MOSFET.

Over Temperature Protection

The thermal shutdown circuitry senses the die temperature.
The threshold is typically set at 142 °C with 75 °C hysteresis.
When the die temperature rises above this threshold the power
MOSFET is disabled and remains disabled until the die
temperature falls by 75 °C, at which point it is re-enabled. A
large hysteresis of 75 °C (typical) is provided to prevent over­heating of the PC board due to a continuous fault condition.

Current Limit

The current limit circuit senses the current in the power
MOSFET. When this current exceeds the internal threshold
(I

), the power MOSFET is turned off for the remainder of that

LIMIT

cycle. The current limit state machine reduces the current limit
threshold by discrete amounts under medium and light loads.

The leading edge blanking circuit inhibits the current limit
comparator for a short time (t

) after the power MOSFET is

LEB

turned on. This leading edge blanking time has been set so
that current spikes caused by capacitance and secondary-side
rectifier reverse recovery time will not cause premature
termination of the switching pulse.

Auto-Restart

In the event of a fault condition such as output overload, output
short-circuit, or an open loop condition, TinySwitch-4 enters
into auto-restart operation. An internal counter clocked by the
oscillator is reset every time the ENABLE/UNDERVOLTAGE pin

is pulled low. If the ENABLE/UNDERVOLTAGE pin is not pulled
low for 64 ms, the power MOSFET switching is normally
disabled for 2.5 seconds (except in the case of line undervoltage
condition, in which case it is disabled until the condition is
removed). The auto-restart alternately enables and disables the
switching of the power MOSFET until the fault condition is
removed. Figure 6 illustrates auto-restart circuit operation in the
presence of an output short-circuit.

In the event of a line undervoltage condition, the switching of
the power MOSFET is disabled beyond its normal 2.5 seconds
until the line undervoltage condition ends.

Adaptive Switching Cycle On-Time Extension

Adaptive switching cycle on-time extension keeps the cycle on
until current limit is reached, instead of prematurely terminating
after the DC

signal goes low. This feature reduces the

MAX

minimum input voltage required to maintain regulation, extending
hold-up time and minimizing the size of bulk capacitor required.
The on-time extension is disabled during the start-up of the
power supply, until the power supply output reaches regulation.

Line Undervoltage Sense Circuit

The DC line voltage can be monitored by connecting an
external resistor from the DC line to the ENABLE/
UNDERVOLTAGE pin. During power-up or when the switching
of the power MOSFET is disabled in auto-restart, the current
into the ENABLE/UNDERVOLTAGE pin must exceed 25 μA to
initiate switching of the power MOSFET. During power-up, this
is accomplished by holding the BYPASS/MULTI-FUNCTION pin
to 4.9 V while the line undervoltage condition exists. The
BYPASS/MULTI-FUNCTION pin then rises from 4.9 V to 5.85 V
when the line undervoltage condition goes away. When the
switching of the power MOSFET is disabled in auto-restart
mode and a line undervoltage condition exists, the auto-restart
counter is stopped. This stretches the disable time beyond its
normal 2.5 seconds until the line undervoltage condition ends.

The line undervoltage circuit also detects when there is no
external resistor connected to the ENABLE/UNDERVOLTAGE
pin (less than ~2 μA into the pin). In this case the line
undervoltage function is disabled.

TinySwitch-4 Operation

TinySwitch-4 devices operate in the current limit mode. When
enabled, the oscillator turns the power MOSFET on at the
beginning of each cycle. The MOSFET is turned off when the
current ramps up to the current limit or when the DC

MAX

limit is
reached. Since the highest current limit level and frequency of
a TinySwitch-4 design are constant, the power delivered to the
load is proportional to the primary inductance of the transformer
and peak primary current squared. Hence, designing the
supply involves calculating the primary inductance of the
transformer for the maximum output power required. If the
TinySwitch-4 is appropriately chosen for the power level, the
current in the calculated inductance will ramp up to current limit

Figure 6. Auto-Restart Operation.

before the DC

limit is reached.

MAX

4

Rev. A 09/12

www.powerint.com

V

DRAIN

V

EN

CLOCK

DC

DRAIN

I

MAX

PI-2749-082305

V

DRAIN

V

EN

CLOCK

DC

DRAIN

I

MAX

PI-2667-082305

PI-2661-082305

V

DRAIN

V

EN

CLOCK

DC

DRAIN

I

MAX

Enable Function

TinySwitch-4 senses the ENABLE/UNDERVOLTAGE pin to
determine whether or not to proceed with the next switching
cycle. The sequence of cycles is used to determine the current
limit. Once a cycle is started, it always completes the cycle
(even when the ENABLE/UNDERVOLTAGE pin changes state
half way through the cycle). This operation results in a power
supply in which the output voltage ripple is determined by the
output capacitor, amount of energy per switch cycle and the
delay of the feedback.

TNY284-290

The ENABLE/UNDERVOLTAGE pin signal is generated on the
secondary by comparing the power supply output voltage with
a reference voltage. The ENABLE/UNDERVOLTAGE pin signal
is high when the power supply output voltage is less than the
reference voltage. In a typical implementation, the ENABLE/
UNDERVOLTAGE pin is driven by an optocoupler. The collector
of the optocoupler transistor is connected to the ENABLE/
UNDERVOLTAGE pin and the emitter is connected to the
SOURCE pin. The optocoupler LED is connected in series with

Figure 7. Operation at Near Maximum Loading.

V

EN

CLOCK

DC

MAX

I

DRAIN

V

DRAIN

Figure 9. Operation at Medium Loading.

Figure 8. Operation at Moderately Heavy Loading.

PI-2377-082305

Figure 10. Operation at Very Light Load.

www.powerint.com

5

Rev. A 09/12

TNY284-290

12

12

a Zener diode across the DC output voltage to be regulated.
When the output voltage exceeds the target regulation voltage
level (optocoupler LED voltage drop plus Zener voltage), the
optocoupler LED will start to conduct, pulling the ENABLE/
UNDERVOLTAGE pin low. The Zener diode can be replaced by
a TL431 reference circuit for improved accuracy.

ON/OFF Operation with Current Limit State Machine

The internal clock of the TinySwitch-4 runs all the time. At the
beginning of each clock cycle, it samples the ENABLE/
UNDERVOLTAGE pin to decide whether or not to implement a
switch cycle, and based on the sequence of samples over
multiple cycles, it determines the appropriate current limit. At
high loads, the state machine sets the current limit to its highest
value. At lighter loads, the state machine sets the current limit
to reduced values.

200

100

10

V

DC-INPUT

0

5

V

BYPASS

0

At near maximum load, TinySwitch-4 will conduct during nearly
all of its clock cycles (Figure 7). At slightly lower load, it will
“skip” additional cycles in order to maintain voltage regulation at
the power supply output (Figure 8). At medium loads, cycles
will be skipped and the current limit will be reduced (Figure 9).
At very light loads, the current limit will be reduced even further
(Figure 10). Only a small percentage of cycles will occur to
satisfy the power consumption of the power supply.

The response time of the ON/OFF control scheme is very fast
compared to PWM control. This provides tight regulation and
excellent transient response.

Power-Up/Down

The TinySwitch-4 requires only a 0.1 μF capacitor on the
BYPASS/MULTI-FUNCTION pin to operate with standard

200

100

PI-2383-030801

10

V

DC-INPUT

0

5

V

BYPASS

0

PI-2381-1030801

400

200

V

DRAIN

0

0

Time (ms)

Figure 11. Power-Up with Optional External UV Resistor (4 MW)

Connected to EN/UV Pin.

200

100

V

DC-INPUT

0

400

300

200

V

DRAIN

100

0

0

.5 1

Time (s)

Figure 13. Normal Power-Down Timing (without UV).

400

200

V

DRAIN

0

0

Time (ms)

Figure 12. Power-Up without Optional External UV Resistor

Connected to EN/UV Pin.

200

PI-2348-030801

100

400

300

200

100

0

0

0

V

DC-INPUT

V

DRAIN

2.5 5

Time (s)

Figure 14. Slow Power-Down Timing with Optional External (4 MW)

UV Resistor Connected to EN/UV Pin.

PI-2395-030801

6

Rev. A 09/12

www.powerint.com

TNY284-290

current limit. Because of its small size, the time to charge this
capacitor is kept to an absolute minimum, typically 0.6 ms. The
time to charge will vary in proportion to the BYPASS/MULTI­FUNCTION pin capacitor value when selecting different current
limits. Due to the high bandwidth of the ON/OFF feedback,
there is no overshoot at the power supply output. When an
external resistor (4 MW) is connected from the positive DC input
to the ENABLE/UNDERVOLTAGE pin, the power MOSFET
switching will be delayed during power-up until the DC line
voltage exceeds the threshold (100 V). Figures 11 and 12 show
the power-up timing waveform in applications with and without
an external resistor (4 MW) connected to the ENABLE/
UNDERVOLTAGE pin. Under start-up and overload conditions,
when the conduction time is less than 400 ns, the device
reduces the switching frequency to maintain control of the peak
drain current.

During power-down, when an external resistor is used, the
power MOSFET will switch for 64 ms after the output loses
regulation. The power MOSFET will then remain off without any
glitches since the undervoltage function prohibits restart when
the line voltage is low.

Figure 13 illustrates a typical power-down timing waveform.
Figure 14 illustrates a very slow power-down timing waveform
as in standby applications. The external resistor (4 MW) is
connected to the ENABLE/UNDERVOLTAGE pin in this case to
prevent unwanted restarts.

No bias winding is needed to provide power to the chip
because it draws the power directly from the DRAIN pin (see
Functional Description). This has two main benefits. First, for a
nominal application, this eliminates the cost of a bias winding

and associated components. Secondly, for battery charger
applications, the current-voltage characteristic often allows the
output voltage to fall close to 0 V while still delivering power.
TinySwitch-4 accomplishes this without a forward bias winding
and its many associated components. For applications that
require very low no-load power consumption (50 mW), a resistor
from a bias winding to the BYPASS/MULTI-FUNCTION pin can
provide the power to the chip. The minimum recommended
current supplied is 1 mA. The BYPASS/MULTI-FUNCTION pin
in this case will be clamped at 6.4 V. This method will eliminate
the power draw from the DRAIN pin, thereby reducing the
no-load power consumption and improving full-load efficiency.

Current Limit Operation

Each switching cycle is terminated when the DRAIN current
reaches the current limit of the device. Current limit operation
provides good line ripple rejection and relatively constant power
delivery independent of input voltage.

BYPASS/MULTI-FUNCTION Pin Capacitor

The BYPASS/MULTI-FUNCTION pin can use a ceramic
capacitor as small as 0.1 μF for decoupling the internal power
supply of the device. A larger capacitor size can be used to
adjust the current limit. For TNY285-290, a 1 μF BYPASS/
MULTI-FUNCTIONAL pin capacitor will select a lower current
limit equal to the standard current limit of the next smaller
device and a 10 μF BYPASS/MULTI-FUNCTIONAL pin capacitor
will select a higher current limit equal to the standard current
limit of the next larger device. The higher current limit level of
the TNY290 is set to 850 mA typical. The TNY284 MOSFET
does not have the capability for increased current limit so this
feature is not available in this device.

40

35

30

25

Maximum Over Power (W)

20

85 115100 130 145 160 175 190 250 265220205 235

Input Voltage (VAC)

Figure 15. Comparison of Maximum Overpower for TinySwitch-4 and

TinySwitch-III as a Function of Input Voltage (Data Collected from
RDK-295 20 W Reference Design).

TNY290
TNY280

PI-6788-052312

www.powerint.com

7

Rev. A 09/12

TNY284-290

BR1

2KBP10M

1000 V

C2
68 µF
450 V

L1

10 mH

RT1

Ω

6

C1

100 nF

F1

275 VAC

5 A

90 - 295

VAC

In a PC standby application input stage

will be part of main power supply input

C3

2.2 nF
1 kV

R12

2 M

Ω

TinySwitch-4

U1

TNY290PG

R13

2 M

Ω

P6KE150A

22

1/2 W

UF4006-E3

D

S

C16

100 nF

100 V

VR1

R1

Ω

EN/UV

BP/M

D1

250 VAC

1 9,10

3

C9

10

µ

16 V

C13

2.2 nF

T1

EE22

R15

1.5 M
1/8 W

F

STPS30L60CT

7,8

4

5

Ω

R3

4.7

Ω

1/2 W

D4

D3

1N4937

C4

100 µF

50 V

1N5254

VR2

27 V

C5

1.5 nF
100 V

PC817

2.2
50 V

U3

C11

C6, C7

1500 µF

10 V

R2

Ω

8.2

30 k
1/8 W

µ

F

R4

C8

1000 µF

10 V

L2

2.2 µH

R8

1 k

1/8 W

R14

3.3 k
1/8 W

R6

10 k

1%

Ω

C10

47 nF

Ω

100 V

PI-6559-062012

Ω

R9

Ω

47

Ω

U2

TL431

10 k

1%

R7

5 V, 4 A

RTN

Ω

Figure 16. TNY290PG, 5 V, 4 A Universal Input Power Supply.

Applications Example

The circuit shown in Figure 16 is a low cost, high efficiency,
flyback power supply designed for 5 V, 4 A output from
universal input using the TNY290PG.

The supply features undervoltage lockout, primary sensed
output overvoltage latching shutdown protection, high
efficiency (>80%), and very low no-load consumption (<50 mW
at 265 VAC). Output regulation is accomplished using a simple
Zener reference and optocoupler feedback.

The rectified and filtered input voltage is applied to the primary
winding of T1. The other side of the transformer primary is
driven by the integrated MOSFET in U1. Diode D1, C3, R1, and
VR1 comprise the clamp circuit, limiting the leakage inductance
turn-off voltage spike on the DRAIN pin to a safe value.

The output voltage is regulated by TL431 U2. When the output
voltage ripple exceeds the sum of the U2 (CATHODE D6) and
optocoupler LED forward drop, current will flow in the
optocoupler LED. This will cause the transistor of the
optocoupler to sink current. When this current exceeds the
ENABLE pin threshold current the next switching cycle is
inhibited. When the output voltage falls below the feedback
threshold, a conduction cycle is allowed to occur and, by
adjusting the number of enabled cycles, output regulation is
maintained. As the load reduces, the number of enabled

cycles decreases, lowering the effective switching frequency
and scaling switching losses with load. This provides almost
constant efficiency down to very light loads, ideal for meeting
energy efficiency requirements.

As the TinySwitch-4 devices are completely self-powered, there
is no requirement for an auxiliary or bias winding on the
transformer. However by adding a bias winding, the output
overvoltage protection feature can be configured, protecting the
load against open feedback loop faults.

When an overvoltage condition occurs, such that bias voltage
exceeds the sum of VR2 and the BYPASS/MULTIFUNCTION
(BYPASS/MULTI-FUNCTIONAL) pin voltage, current begins to
flow into the BYPASS/MULTI-FUNCTIONAL pin. When this
current exceeds ISD the internal latching shutdown circuit in
TinySwitch-4 is activated. This condition is reset when the
ENABLE/UNDERVOLTAGE pin current flowing through R12 and
R13 drop below 18.75 μA each AC line half-cycle. The
configuration of Figure 16 is therefore non-latching for an
overvoltage fault. Latching overvoltage protection can be
achieved by connecting R12 and R13 to the positive terminal of
C2, at the expense of higher standby consumption. In the
example shown, on opening the loop, the OVP trips at an
output of 17 V.

For lower no-load input power consumption, the bias winding
may also be used to supply the TinySwitch-4 device. Resistor

8

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TNY284-290

R4 feeds current into the BYPASS/MULTI-FUNCTIONAL pin,
inhibiting the internal high-voltage current source that normally
maintains the BYPASS/MULTI-FUNCTIONAL pin capacitor
voltage (C7) during the internal MOSFET off-time. This reduces
the no-load consumption of this design from 140 mW to 40 mW
at 265 VAC.

Undervoltage lockout is configured by R5 connected between
the DC bus and ENABLE/UNDERVOLTAGE pin of U1. When
present, switching is inhibited until the current in the ENABLE/
UNDERVOLTAGE pin exceeds 25 μA. This allows the start-up
voltage to be programmed within the normal operating input
voltage range, preventing glitching of the output under abnormal
low voltage conditions and also on removal of the AC input.

In addition to the simple input pi filter (C1, L1, C2) for differential
mode EMI, this design makes use of E-Shield™ shielding
techniques in the transformer to reduce common mode EMI
displacement currents, and R2 and C4 as a damping network
to reduce high frequency transformer ringing. These techniques,
combined with the frequency jitter of TNY288, give excellent
conducted and radiated EMI performance with this design
achieving >12 dBμV of margin to EN55022 Class B conducted
EMI limits.

For design flexibility the value of C7 can be selected to pick one
of the 3 current limits options in U1. This allows the designer to
select the current limit appropriate for the application.

• Standard current limit (I

) is selected with a 0.1 μF BYPASS/

LIMIT

MULTI-FUNCTIONAL pin capacitor and is the normal choice
for typical enclosed adapter applications.

• When a 1 μF BYPASS/MULTI-FUNCTIONAL pin capacitor is

used, the current limit is reduced (I

LIMITred

or I

-1) offering

LIMIT

reduced RMS device currents and therefore improved
efficiency, but at the expense of maximum power capability.
This is ideal for thermally challenging designs where dissipa­tion must be minimized.

• When a 10 μF BYPASS/MULTI-FUNCTIONAL pin capacitor is

used, the current limit is increased (I

LIMITinc

or I

LIMIT

+1), extending
the power capability for applications requiring higher peak
power or continuous power where the thermal conditions allow.

Further flexibility comes from the current limits between
adjacent TinySwitch-4 family members being compatible. The
reduced current limit of a given device is equal to the standard
current limit of the next smaller device and the increased
current limit is equal to the standard current limit of the next
larger device.

Key Application Considerations

TinySwitch-4 vs. TinySwitch-III

Function

BV

DSS

Line Compensated OCP N/A Yes

Typical OCP Change from
85 VAC to 265 VAC

UV Threshold 25 μA ±10% 25 μA ±5%

VBP Reset Voltage 2.6 V Typical 3.0 V Typical

Packages

Table 2. Comparisons Between TinySwitch-III and TinySwitch-4.

TinySwitch-III TinySwitch-4

700 V 725 V

>40% <15%

DIP-8C (P),

SMD-8C (G)

DIP-8C (P),

eSO P-12 B ( K ),

SO-8C (D)

TinySwitch-4 Design Considerations

Output Power Table

The data sheet output power table (Table 1) represents the
minimum practical continuous output power level that can be
obtained under the following assumed conditions:

1. The minimum DC input voltage is 100 V or higher for 85 VAC
input, or 220 V or higher for 230 VAC input or 115 VAC with
a voltage doubler. The value of the input capacitance should
be sized to meet these criteria for AC input designs.

2. Efficiency of 75%.

3. Minimum data sheet value of I2f.

4. Transformer primary inductance tolerance of ±10%.

5. Reflected output voltage (VOR) of 135 V.

6. Voltage only output of 12 V with a fast PN rectifier diode.

7. Continuous conduction mode operation with transient KP*
value of 0.25.

8. Increased current limit is selected for peak and open frame
power columns and standard current limit for adapter columns.

9. The part is board mounted with SOURCE pins soldered to a
sufficient area of copper and/or a heat sink is used to keep
the SOURCE pin temperature at or below 110 °C.

10. Ambient temperature of 50 °C for open frame designs and
40 °C for sealed adapters.

*Below a value of 1, KP is the ratio of ripple to peak primary
current. To prevent reduced power capability due to premature
termination of switching cycles a transient KP limit of ≥0.25 is
recommended. This prevents the initial current limit (I

INIT

) from

being exceeded at MOSFET turn-on.

For reference, Table 3 provides the minimum practical power
delivered from each family member at the three selectable
current limit values. This assumes open frame operation (not
thermally limited) and otherwise the same conditions as listed
above. These numbers are useful to identify the correct current
limit to select for a given device and output power requirement.

Table 2 compares the features and performance differences
between TinySwitch-4 and TinySwitch-III. TinySwitch-4 is pin
compatible to TinySwitch-III with improved features. It requires
minimum design effort to adapt into a new design. In addition
to the feature enhancement, TinySwitch-4 offers two new
packages; eSOP-12B (K) and SO-8C (D) to meet various
application requirements.

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Overvoltage Protection

The output overvoltage protection provided by TinySwitch-4
uses an internal latch that is triggered by a threshold current of
approximately 5.5 mA into the BYPASS/MULTI-FUNCTIONAL
pin. In addition to an internal filter, the BYPASS/MULTI­FUNCTIONAL pin capacitor forms an external filter providing
noise immunity from inadvertent triggering. For the bypass

9

Rev. A 09/12

TNY284-290

capacitor to be effective as a high frequency filter, the capacitor
should be located as close as possible to the SOURCE and
BYPASS/MULTI-FUNCTIONAL pins of the device.

Peak Output Power Table

230 VAC ± 15% 85-265 VAC

Product

TNY284P 9.1 W 10.9 W 9.1 W 7.1 W 8.5 W 7.1 W

TNY285P 10.8 W 12 W 15.1 W 8.4 W 9.3 W 11.8 W

TNY286P 11.8 W 15.3 W 19.4 W 9.2 W 11.9 W 15.1 W

TNY287P 15.1 W 19.6 W 23.7 W 11.8 W 15.3 W 18.5 W

TNY288P 19.4 W 24 W 28 W 15.1 W 18.6 W 21.8 W

TNY289P 23.7 W 28.4 W 32.2 W 18.5 W 22 W 25.2 W

TNY290P 28 W 32.7 W 36.6 W 21.8 W 25.4 W 28.5 W

Table 3. Minimum Practical Power at Three Selectable Current Limit Levels.

I

LIMIT

-1 I

LIMITILIMIT

+1 I

LIMIT

-1 I

LIMITILIMIT

+1

For best performance of the OVP function, it is recommended
that a relatively high bias winding voltage is used, in the range of
15 V - 30 V. This minimizes the error voltage on the bias
winding due to leakage inductance and also ensures adequate
voltage during no-load operation from which to supply the
BYPASS/MULTI-FUNCTIONAL pin for reduced no-load
consumption.

Selecting the Zener diode voltage to be approximately 6 V
above the bias winding voltage (28 V for 22 V bias winding)
gives good OVP performance for most designs, but can be
adjusted to compensate for variations in leakage inductance.
Adding additional filtering can be achieved by inserting a low
value (10 W to 47 W) resistor in series with the bias winding
diode and/or the OVP Zener as shown by R7 and R3 in Figure 16.
The resistor in series with the OVP Zener also limits the
maximum current into the BYPASS/MULTI-FUNCTIONAL pin.

Reducing No-load Consumption

As TinySwitch-4 is self-powered from the BYPASS/MULTI­FUNCTIONAL pin capacitor, there is no need for an auxiliary or
bias winding to be provided on the transformer for this purpose.
Typical no-load consumption when self-powered is <150 mW at
265 VAC input. The addition of a bias winding can reduce this
down to <50 mW by supplying the TinySwitch-4 from the lower
bias voltage and inhibiting the internal high-voltage current
source. To achieve this, select the value of the resistor (R8 in
Figure 16) to provide the data sheet DRAIN supply current. In
practice, due to the reduction of the bias voltage at low load,
start with a value equal to 40% greater than the data sheet
maximum current, and then increase the value of the resistor to
give the lowest no-load consumption.

Audible Noise

The cycle skipping mode of operation used in TinySwitch-4 can
generate audio frequency components in the transformer. To
limit this audible noise generation the transformer should be
designed such that the peak core flux density is below
3000 Gauss (300 mT). Following this guideline and using the
standard transformer production technique of dip varnishing

practically eliminates audible noise. Vacuum impregnation of
the transformer should not be used due to the high primary
capacitance and increased losses that result. Higher flux
densities are possible, however careful evaluation of the audible
noise performance should be made using production
transformer samples before approving the design.

Ceramic capacitors that use dielectrics such as Z5U, when
used in clamp circuits, may also generate audio noise. If this is
the case, try replacing them with a capacitor having a different
dielectric or construction, for example a film type.

TinySwitch-4 Layout Considerations

Layout

See Figure 17 for a recommended circuit board layout for
TinySwitch-4.

Single Point Grounding

Use a single point ground connection from the input filter
capacitor to the area of copper connected to the SOURCE pins.

Bypass Capacitor (CBP)

The BYPASS/MULTI-FUNCTIONAL pin capacitor must be
located directly adjacent to the BYPASS/MULTI-FUNCTIONAL
and SOURCE pins.

If a 0.1 μF bypass capacitor has been selected it should be a
high frequency ceramic type (e.g. with X7R dielectric). It must
be placed directly between the ENABLE and SOURCE pins to
filter external noise entering the BYPASS pin. If a 1 μF or 10 μF
bypass capacitor was selected then an additional 0.1 μF
capacitor should be added across BYPASS and SOURCE pins
to provide noise filtering (see Figure 17).

ENABLE/UNDERVOLTAGE Pin

Keep traces connected to the ENABLE/UNDERVOLTAGE pin
short and, as far as is practical, away from all other traces and
nodes above source potential including, but not limited to, the
bypass, drain and bias supply diode anode nodes.

Primary Loop Area

The area of the primary loop that connects the input filter
capacitor, transformer primary and TinySwitch-4 should be kept
as small as possible.

Primary Clamp Circuit

A clamp is used to limit peak voltage on the DRAIN pin at
turn-off. This can be achieved by using an RCD clamp or a
Zener (~200 V) and diode clamp across the primary winding.
To reduce EMI, minimize the loop from the clamp components
to the transformer and TinySwitch-4.

Thermal Considerations

The SOURCE pins are internally connected to the IC lead frame
and provide the main path to remove heat from the device.
Therefore all the SOURCE pins should be connected to a
copper area underneath the TinySwitch-4 to act not only as a
single point ground, but also as a heat sink. As this area is
connected to the quiet source node, this area should be
maximized for good heat sinking. Similarly for axial output
diodes, maximize the PCB area connected to the cathode.

10

Rev. A 09/12

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TNY284-290

Safety Spacing

Y1-

Capacitor

+

High-Voltage

-

Input Filter Capacitor

PRI

BIAS

T

r

a

SEC

n

S

S

S

TOP VIEW

*C

is a 0.1 µF high frequency noise bypass capacitor (the high frequency 0.1 µF capacitor eliminates need for CBP if I

HF

Figure 17. Recommended Circuit Board Layout for TinySwitch-4 with Undervoltage Lock Out Resistor.

S

*C

HF/CBP

D

BP/M

TinySwitch-4

EN/

UV

C

BP

PRI

BIAS

s

f

o

r

m

e

r

Opto-

coupler

Maximize hatched copper
areas ( ) for optimum
heat sinking

Output

Rectier

DC

OUT

LIMIT

Output Filter

Capacitor

+-

selection requires 0.1 µF).

PI-6651-060612

Y Capacitor

The placement of the Y capacitor should be directly from the
primary input filter capacitor positive terminal to the common/
return terminal of the transformer secondary. Such a placement
will route high magnitude common mode surge currents away
from the TinySwitch-4 device. Note – if an input π (C, L, C) EMI
filter is used then the inductor in the filter should be placed
between the negative terminals of the input filter capacitors.

Optocoupler

Place the optocoupler physically close to the TinySwitch-4 to
minimizing the primary-side trace lengths. Keep the high
current, high-voltage drain and clamp traces away from the
optocoupler to prevent noise pick up.

Output Diode

For best performance, the area of the loop connecting the
secondary winding, the output diode and the output filter
capacitor, should be minimized. In addition, sufficient copper
area should be provided at the anode and cathode terminals of
the diode for heat sinking. A larger area is preferred at the quiet
cathode terminal. A large anode area can increase high
frequency radiated EMI.

PC Board Leakage Currents

TinySwitch-4 is designed to optimize energy efficiency across
the power range and particularly in standby/no-load conditions.
Current consumption has therefore been minimized to achieve
this performance. The ENABLE/UNDERVOLTAGE pin under­voltage feature for example has a low threshold (~1 μA) to
detect whether an undervoltage resistor is present.

Parasitic leakage currents into the ENABLE/UNDERVOLTAGE
pin are normally well below this 1 μA threshold when PC board
assembly is in a well controlled production facility. However, high
humidity conditions together with board and/or package
contamination, either from no-clean flux or other contaminants,
can reduce the surface resistivity enough to allow parasitic
currents >1 μA to flow into the ENABLE/UNDERVOLTAGE pin.
These currents can flow from higher voltage exposed solder
pads close to the ENABLE/UNDERVOLTAGE pin such as the
BYPASS/MULTI-FUNCTIONAL pin solder pad preventing the
design from starting up. Designs that make use of the
undervoltage lockout feature by connecting a resistor from the
high-voltage rail to the ENABLE/UNDERVOLTAGE pin are not
affected.

If the contamination levels in the PC board assembly facility are
unknown, the application is open frame or operates in a high
pollution degree environment and the design does not make
use of the undervoltage lockout feature, then an optional
390 kW resistor should be added from ENABLE/UNDERVOLTAGE
pin to SOURCE pin to ensure that the parasitic leakage current
into the ENABLE/UNDERVOLTAGE pin is well below 1 μA.

Note that typical values for surface insulation resistance (SIR)
where no-clean flux has been applied according to the
suppliers’ guidelines are >>10 MW and do not cause this issue.

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11

Rev. A 09/12

TNY284-290

Quick Design Checklist

As with any power supply design, all TinySwitch-4 designs
should be verified on the bench to make sure that component
specifications are not exceeded under worst case conditions.
The following minimum set of tests is strongly recommended:

1. Maximum drain voltage – Verify that VDS does not exceed
675 V at highest input voltage and peak (overload) output
power. The 50 V margin to the 725 V BV
gives margin for design variation.

2. Maximum drain current – At maximum ambient temperature,
maximum input voltage and peak output (overload) power,
verify drain current waveforms for any signs of transformer
saturation and excessive leading edge current spikes at
start-up. Repeat under steady-state conditions and verify
that the leading edge current spike event is below I
the end of the t

. Under all conditions, the maximum

LEB(MIN)

drain current should be below the specified absolute
maximum ratings.

3. Thermal Check – At specified maximum output power,
minimum input voltage and maximum ambient temperature,
verify that the temperature specifications are not exceeded
for TinySwitch-4, transformer, output diode, and output
capacitors. Enough thermal margin should be allowed for
part-to-part variation of the R

of TinySwitch-4 as

DS(ON)

specified in the data sheet. Under low-line, maximum
power, a maximum TinySwitch-4 SOURCE pin temperature
of 110 °C is recommended to allow for these variations.

specification

DSS

LIMIT(MIN)

at

12

Rev. A 09/12

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TNY284-290

Absolute Maximum Ratings

(1,4)

DRAIN Voltage ...................................................-0.3 V to 725 V

DRAIN Peak Current: TNY284 ......................... 400 (750) mA

TNY285 ....................... 560 (1050) mA

TNY286 ....................... 720 (1350) mA

TNY287 ....................... 880 (1650) mA

TNY288 ..................... 1040 (1950) mA

TNY289 ..................... 1200 (2250) mA

TNY290 ..................... 1360 (2550) mA

EN/UV Voltage ...................................................... -0.3 V to 9 V

EN/UV Current ........................................................... ... 100 mA

BP/M Voltage .................................................. ......-0.3 V to 9 V

Storage Temperature ...................................... -65 °C to 150 °C

Maximum Junction Temperature
Lead Temperature

(4)

.........................................................260 °C

(3)

................... -40 °C to 150 °C

Thermal Resistance

Thermal Impedance: P Package:

(qJA) ............................ .... 70 °C/W

(1)

(qJC)

.................................................. 11 °C/W

(2)

; 60 °C/W

D Package:

(qJA) ............................ .. 100 °C/W

(1)

(qJC)

.................................................. 30 °C/W

(2)

; 80 °C/W

K Package:

(qJA) ............................ .... 45 °C/W

(4)

(qJC)

....................................................2 °C/W

(2)

; 38 °C/W

Notes:

(2)

1. All voltages referenced to SOURCE, TA = 25 °C.

(2)

2. The higher peak DRAIN current is allowed while the DRAIN

(2)

voltage is simultaneously less than 400 V.

(2)

3. Normally limited by internal circuitry.

(2)

4. 1/16 in. from case for 5 seconds.

(2)

5. Maximum ratings specified may be applied one at a time,

(2)

without causing permanent damage to the product. Exposure
to Absolute Rating conditions for extended periods of time
may affect product reliability.

Notes:

(3)

1. Measured on the SOURCE pin close to the plastic interface.

2. Soldered to 0.36 sq. in. (232 mm2), 2 oz. (610 g/m2) copper clad.

3. Soldered to 1 sq. in. (645 mm2), 2 oz. (610 g/m2) copper clad.

(3)

4. The case temperature is measured at the bottom-side
exposed pad.

(3)

Parameter Symbol

Control Functions

Output Frequency
in Standard Mode

Maximum Duty Cycle DC

EN/UV Pin Upper
Turnoff Threshold
Current

EN/UV Pin
Voltage

DRAIN Supply Current

f

V

OSC

I

DIS

I

S1

I

S2

MAX

EN

Conditions

SOURCE = 0 V; TJ = -40 to 125 °C

See Figure 18

(Unless Otherwise Specified)

TJ = 25 °C

See Figure 5

Average 124 132 140

Peak-to-peak Jitter 8

S1 Open 62 67 %

I

= 25 μA 1.8 2.2 2.6

EN/UV

I

= -25 μA 0.8 1.2 1.6

EN/UV

EN/UV Current > I

DIS

(MOSFET Not Switching) See Note A

TNY284 360 400

TNY285 410 440

EN/UV Open

(MOSFET

Switching at f

See Note B

OSC

)

TNY286 430 470

TNY287 510 550

TNY288 615 650

TNY289 715 800

TNY290 875 930

Min Typ Max Units

kHz

-150 -122 -90 μA

V

330 μA

μA

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13

Rev. A 09/12

TNY284-290

Parameter Symbol

Control Functions (cont.)

BP/M Pin
Charge Current

I

I

CH1

CH2

Conditions

SOURCE = 0 V; TJ = -40 to 125 °C

See Figure 18

(Unless Otherwise Specified)

V

= 0 V, TJ = 25 °C

BP/M

See Note C, D

V

= 4 V, TJ = 25 °C

BP/M

See Note C, D

Min Typ Max Units

-6.5 -4.5 -2.5

mA

-4.7 -2.8 -1.4

BP/M Pin Voltage V

BP/M Pin
Voltage Hysteresis

BP/M Pin
Shunt Voltage

V

EN/UV Pin Line Under­voltage Threshold

EN/UV Pin – Reset
Hysteresis (Following
Latch Off with BP/M
Pin Current >ISD)

Circuit Protection

Standard Current Limit
(BP/M Capacitor =

0.1 μF) See Note D

V

I

BP/M

BP/MH

SHUNT

I

LUV

LIMIT

See Note C 5.6 5.85 6.3 V

IBP = 2 mA 6.0 6.4 6.85 V

TJ = 25 °C 23.75 25 26.25 μA

TJ = 25 °C

See Note G

di/dt = 50 mA/μs

TJ = 25 °C

See Note E

di/dt = 55 mA/μs

TJ = 25 °C

See Note E

di/dt = 70 mA/μs

TJ = 25 °C

See Note E

di/dt = 90 mA/μs

TJ = 25 °C

See Note E

0.80 0.95 1.20 V

3 5 8 μA

TNY284P/D/K 233 250 267

TNY285P/D/K 256 275 294

TNY286P/D/K 326 350 374

TNY287P/D/K 419 450 481

mA

14

Rev. A 09/12

di/dt = 110 mA/μs

TJ = 25 °C

See Note E

di/dt = 130 mA/μs

TJ = 25 °C

See Note E

di/dt = 150 mA/μs

TJ = 25 °C

See Note E

TNY288P/K 512 550 588

TNY289P/K 605 650 695

TNY290P/K 698 750 802

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Parameter Symbol

Circuit Protection (cont.)

Conditions

SOURCE = 0 V; TJ = -40 to 125 °C

See Figure 18

(Unless Otherwise Specified)

di/dt = 42 mA/μs

TJ = 25 °C

TNY284P/D/K

See Note E

di/dt = 50 mA/μs

TJ = 25 °C

TNY285P/D/K 233 250 277

See Note E

di/dt = 55 mA/μs

TJ = 25 °C

TNY286P/D/K 256 275 305

See Notes E

TNY284-290

Min Typ Max Units

196 210 233

Reduced Current Limit
(BP/M Capacitor =
1 μF) See Note D

Increased Current Limit
(BP/M Capacitor =
10 μF) See Note D

I

LIMITred

I

LIMITinc

di/dt = 70 mA/μs

TJ = 25 °C

See Notes E

di/dt = 90 mA/μs

TJ = 25 °C

See Notes E

di/dt = 110 mA/μs

TJ = 25 °C

See Notes E

di/dt = 130 mA/μs

TJ = 25 °C

See Notes E

di/dt = 42 mA/μs

TJ = 25 °C

See Notes E, F

di/dt = 70 mA/μs

TJ = 25 °C

See Notes E

di/dt = 90 mA/μs

TJ = 25 °C

See Notes E

di/dt = 110 mA/μs

TJ = 25 °C

See Notes E

TNY287P/D/K 326 350 388

TNY288P/K 419 450 499

TNY289P/K 512 550 610

TNY290P/K 605 650 721

TNY284P/D/K 196 210 233

TNY285P/D/K 326 350 388

TNY286P/D/K 419 450 499

TNY287P/D/K 512 550 610

mA

mA

www.powerint.com

di/dt = 130 mA/μs

TJ = 25 °C

See Notes E

di/dt = 150 mA/μs

TJ = 25 °C

See Notes E

di/dt = 170 mA/μs

TJ = 25 °C

See Notes E

TNY288P/K 605 650 721

TNY289P/K 698 750 833

TNY290P/K

791 850 943

15

Rev. A 09/12

TNY284-290

Parameter Symbol

Circuit Protection (cont.)

Conditions

SOURCE = 0 V; TJ = -40 to 125 °C

See Figure 18

(Unless Otherwise Specified)

Standard Current

Limit, I2f = I

× f

OSC(TYP)

LIMIT(TYP)

2

TNY284-290

TJ = 25 °C

Min Typ Max Units

0.9 ×
I2f

I2f

1.12 ×
I2f

Power Coefficient I2f

Initial Current Limit I

Leading Edge
Blanking Time

Current Limit
Delay

Thermal Shutdown
Temperature

Thermal Shutdown
Hysteresis

BP/M Pin Shutdown
Threshold Current

t

t

T

T

I

INIT

LEB

ILD

SDH

SD

Reduced Current

Limit, I2f = I

× f

OSC(TYP)

LIMITred(TYP)

2

TNY284-290

0.9 ×
I2f

I2f

1.16 ×
I2f

A2Hz

TJ = 25 °C

Increased Current

Limit, I2f = I

× f

OSC(TYP)

LIMITinc(TYP)

2

TNY284-290

0.9 ×
I2f

I2f

1.16 ×
I2f

TJ = 25 °C

See Figure 20

TJ = 25 °C, See Note G

TJ = 25 °C

See Note G

TJ = 25 °C

See Note G, H

SD

0.75 ×
I

LIMIT(MIN)

170 215 ns

150 ns

135 142 150 °C

mA

75 °C

4 6.5 9 mA

BP/M Pin Power-Up
Reset Threshold
Voltage

Output

ON-State
Resistance

16

Rev. A 09/12

V

BP/M(RESET)

R

DS(ON)

TNY284

ID = 25 mA

TNY285

ID = 28 mA

TNY286

ID = 35 mA

1.6 3.0 3.6 V

TJ = 25 °C 28 32

TJ = 100 °C 42 48

TJ = 25 °C 19 22

W

TJ = 100 °C 29 33

TJ = 25 °C 14 16

TJ = 100 °C 21 24

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Parameter Symbol

Output (cont.)

Conditions

SOURCE = 0 V; TJ = -40 to 125 °C

See Figure 18

(Unless Otherwise Specified)

TNY287

ID = 45 mA

TJ = 25 °C 7.8 9.0

TJ = 100 °C 11.7 13.5

TNY284-290

Min Typ Max Units

ON-State
Resistance

OFF-State Drain
Leakage Current

Breakdown
Voltage

DRAIN Supply
Voltage

R

I

I

BV

DS(ON)

DSS1

DSS2

DSS

TNY288

ID = 55 mA

TNY289

ID = 65 mA

TNY290

ID = 75 mA

V

= 6.2 V

BP/M

V

= 0 V

EN/UV

VDS = 560 V
TJ = 125 °C

See Note I

V

= 6.2 V

BP/M

V

= 0 V

EN/UV

VBP = 6.2 V, V

See Note J, TJ = 25 °C

TJ = 25 °C 5.2 6.0

TJ = 100 °C 7.8 9.0

TJ = 25 °C 3.9 4.5

TJ = 100 °C 5.8 6.7

TJ = 25 °C 2.6 3.0

TJ = 100 °C 3.9 4.5

TNY284-286 50

TNY289-290 200

VDS = 375 V,

TJ = 50 °C

15

See Note G, I

= 0 V,

EN/UV

725 V

50 V

W

μATNY287-288 100

Auto-Restart
ON-Time at f

Auto-Restart
Duty Cycle

www.powerint.com

OSC

DC

t

AR

AR

TJ = 25 °C

See Note K

64 ms

TJ = 25 °C 3 %

17

Rev. A 09/12

TNY284-290

NOTES:
A. IS1 is an accurate estimate of device controller current consumption at no-load, since operating frequency is so low under these

conditions. Total device consumption at no-load is the sum of IS1 and I

B. Since the output MOSFET is switching, it is difficult to isolate the switching current from the supply current at the DRAIN. An

alternative is to measure the BYPASS/MULTI-FUNCTIONAL pin current at 6.1 V.
C. BYPASS/MULTI-FUNCTIONAL pin is not intended for sourcing supply current to external circuitry.
D. To ensure correct current limit it is recommended that nominal 0.1 μF / 1 μF / 10 μF capacitors are used. In addition, the BP/M

capacitor value tolerance should be equal or better than indicated below across the ambient temperature range of the target

application. The minimum and maximum capacitor values are guaranteed by characterization.

Nominal BP/M

Pin Cap Value

0.1 μF -60% +100%

1 μF -50% +100%

10 μF -50% NA

Tolerance Relative to Nominal

Capacitor Value

Min Max

E. For current limit at other di/dt values, refer to Figure 25.
F. TNY284 does not have an increased current limit value, but with a 10 μF BYPASS/MULTI-FUNCTIONAL pin capacitor the current

limit is the same as with a 1 μF BYPASS/MULTI-FUNCTIONAL pin capacitor (reduced current limit value).
G. This parameter is derived from characterization.
H. This parameter is derived from the change in current limit measured at 1X and 4X of the di/dt shown in the I
I. I

is the worst case OFF state leakage specification at 80% of BV

DSS1

typical specification under worst case application conditions (rectified 265 VAC) for no-load consumption calculations.
J. Breakdown voltage may be checked against minimum BV

exceeding minimum BV

DSS

.

specification by ramping the DRAIN pin voltage up to but not

DSS

K. Auto-restart on time has the same temperature characteristics as the oscillator (inversely proportional to frequency).

.

DSS2

specification.

and maximum operating junction temperature. I

DSS

LIMIT

DSS2

is a

18

Rev. A 09/12

www.powerint.com

TNY284-290

NOTE: This test circuit is not applicable for current limit or output characteristic measurements.

Figure 18. General Test Circuit.

SD

S

BP/M

S

EN/UV

S

0.1 µF

2 MΩ

470 Ω

5 Ω

S1

150 V

DC

(internal signal)

EN/UV

MAX

470 Ω

10 V

S2

50 V

PI-4079-080905

t

P

Figure 19. Duty Cycle Measurement.

Typical Performance Characteristics

1.10

1.05

1.00

0.95

0.90

0.85

0.80

Typical
Minimum
Maximum

Current Limit (Normalized)

0.75

0.70

0.65

0.60
0 1 2 3 4 5 6

TON (µs)

Figure 21. Current Limit vs. TON for TNY284~287.

TJ = 25 °C

PI-6803-060512

t

V

DRAIN

1

tP =

f

OSC

Figure 20. Output Enable Timing.

EN/UV

1.10

1.05

1.00

0.95

0.90

0.85

0.80

0.75

0.70

Current Limit (Normalized)

0.65

0.60
0 1 2 3 4 5 6

TON (µs)

Figure 22. Current Limit vs. TON for TNY288~290.

PI-2364-012699

TJ = 25 °C

PI-6804-060112

Typical
Minimum
Maximum

www.powerint.com

19

Rev. A 09/12

TNY284-290

Breakdown Voltage

Typical Performance Characteristics (cont.)

1.1

1.0

(Normalized to 25 °C)

0.9

-50 -25 0255075 100 125 150

Junction Temperature (°C)

Figure 23. Breakdown vs. Temperature.

1.4

1.2

1.0

0.8

0.6

(See Figure 21)

0.4

Normalized Current Limit

0.2

TNY284 50 mA/μs
TNY285 55 mA/μs
TNY286 70 mA/μs
TNY287 90 mA/μs
TNY288 110 mA/μs
TNY289 130 mA/μs
TNY290 150 mA/μs

Normalized

di/dt = 1

Note: For the
normalized current
limit value, use the
typical current limit
specied for the
appropriate BP/M
capacitor.

0

1 2 3 4

Normalized di/dt

Figure 25. Standard Current Limit vs. di/dt.

PI-2213-012301

PI-6785-052412

1.05

1.00

95

90

(Normalized to 25 °C)

85

Standard Current Limit

80

-40 0-20 20 40 60 80 100 120

Temperature (C)

Figure 24. Standard Current Limit vs. Temperature.

300

Scaling Factors:

250

200

150

TNY284 1.0
TNY285 1.5
TNY286 2.0
TNY287 3.5
TNY288 5.6
TNY289 7.9
TNY290 11.2

100

Drain Current (mA)

50

T
T

CASE

CASE

0

0 2 4 6 8 10

DRAIN Voltage (V)

Figure 26. Output Characteristic.

PI-6787-053112

PI-6786-052412

=25 °C
=100 °C

Figure 27. C

20

Rev. A 09/12

1000

Scaling Factors:
TNY284 1.0

100

TNY285 1.5
TNY286 2.0
TNY287 3.5
TNY288 5.6
TNY289 7.9
TNY290 11.2

10

Drain Capacitance (pF)

1

0 100 200 300 400 500 600

Drain Voltage (V)

vs. Drain Voltage.

OSS

40

Scaling Factors:

PI-6771-051112

30

20

TNY284 1.0
TNY285 1.5
TNY286 2.0
TNY287 3.5
TNY288 5.6
TNY289 7.9
TNY290 11.2

PI-6772-051112

Power (mW)

10

0

0 100 200 300 400 500 600

Drain Voltage (V)

Figure 28. Drain Capacitance Power.

www.powerint.com

1.2

Under-Voltage Threshold

Typical Performance Characteristics (cont.)

TNY284-290

1.0

0.8

0.6

0.4

(Normalized to 25 °C)

0.2

0

-50 -25 0255075 100 125

Junction Temperature (°C)

Figure 29. Undervoltage Threshold vs. Temperarture.

PI-4281-012306

www.powerint.com

21

Rev. A 09/12

TNY284-290

-E-

.240 (6.10)
.260 (6.60)

Pin 1

-D-

.125 (3.18)
.145 (3.68)

-T-

SEATING
PLANE

.100 (2.54) BSC

D S

⊕

.367 (9.32)
.387 (9.83)

.014 (.36)
.022 (.56)

.004 (.10)

.048 (1.22)
.053 (1.35)

⊕

T E D S

.057 (1.45)
.068 (1.73)

(NOTE 6)

.015 (.38)

MINIMUM

.120 (3.05)
.140 (3.56)

.137 (3.48)

MINIMUM

.010 (.25) M

DIP-8C

Notes:

1. Package dimensions conform to JEDEC specification
MS-001-AB (Issue B 7/85) for standard dual-in-line (DIP)
package with .300 inch row spacing.

2. Controlling dimensions are inches. Millimeter sizes are
shown in parentheses.

3. Dimensions shown do not include mold flash or other
protrusions. Mold flash or protrusions shall not exceed
.006 (.15) on any side.

4. Pin locations start with Pin 1, and continue counter-clock­ wise to Pin 8 when viewed from the top. The notch and/or
dimple are aids in locating Pin 1. Pin 3 is omitted.

5. Minimum metal to metal spacing at the package body for
the omitted lead location is .137 inch (3.48 mm).

6. Lead width measured at package body.

7. Lead spacing measured with the leads constrained to be
perpendicular to plane T.

.008 (.20)
.015 (.38)

.300 (7.62) BSC

(NOTE 7)

.300 (7.62)
.390 (9.91)

PI-3933-100504

P08C

22

Rev. A 09/12

www.powerint.com

SO-8C (D Package)

TNY284-290

0.10 (0.004)

2X

1.35 (0.053)

1.75 (0.069)

0.10 (0.004)

0.25 (0.010)

3.90 (0.154) BSC

2

D

C

Pin 1 ID

1.27 (0.050) BSC

B

4

1.25 - 1.65

(0.049 - 0.065)

2

4.90 (0.193) BSC

A

8

1

4

5

4

0.10 (0.004)

D

6.00 (0.236) BSC

2X

7X 0.31 - 0.51 (0.012 - 0.020)

0.25 (0.010)

7X

SEATING PLANE

C

A-B

C

0.20 (0.008)

M

0.10 (0.004)

2X

C A-B D

C

C

SEATING
PLANE

1.04 (0.041) REF

C

0.40 (0.016)

1.27 (0.050)

H

0.17 (0.007)

0.25 (0.010)

DETAIL A

o

0 - 8

0.25 (0.010)
BSC

DETAIL A

GAUGE
PLANE

D07C

Reference
Solder Pad
Dimensions

1.27 (0.050)

2.00 (0.079)

+

Notes:

1. JEDEC reference: MS-012.

4.90 (0.193)

+

+

+

0.60 (0.024)

2. Package outline exclusive of mold flash and metal burr.

3. Package outline inclusive of plating thickness.

4. Datums A and B to be determined at datum plane H.

5. Controlling dimensions are in millimeters. Inch dimensions
are shown in parenthesis. Angles in degrees.

PI-4526-040110

www.powerint.com

23

Rev. A 09/12

Pin #1 I.D.

(Laser Marked)

0.460 [11.68]

TNY284-290

0.400 [10.16]

2

0.004 [0.10] C A 2X

0.059 [1.50]

eSOP-12B (K Package)

0.356 [9.04]

0.325 [8.26]

Ref, Typ

0.059 [1.50]
Ref, Typ

2X

0.004 [0.10] C B

0.350 [8.89]

7 12

2

Ref.

Max.

7

0.055 [1.40] Ref.

0.225 [5.72]
Max.

0.010 [0.25]

7

°

°

8

0 -

0.034 [0.85]

0.026 [0.65]

DETAIL A (Scale = 9X)

0.010 [0.25]
Ref.

Gauge Plane

Seating Plane

H

C

0.008 [0.20] C

2X, 5/6 Lead Tips

0.098 [2.49]

0.086 [2.18]

0.006 [0.15]

0.000 [0.00]
Seating plane to

package bottom
standoff

0.028 [0.71]

1

2

0.067 [1.70]

1

2

3

4

6

3 4 6 6 1

0.023 [0.58]

0.018 [0.46]

11×

3 4

0.010 (0.25) M C A B

B

0.120 [3.05] Ref

0.070 [1.78]

TOP VIEW BOTTOM VIEW

0.032 [0.80]

0.029 [0.72]

0.092 [2.34]

0.086 [2.18]

Seating

0.004 [0.10] C

SIDE VIEW

C

Detail A

0.306 [7.77]
Ref.

END VIEW

Plane

Land Pattern

0.217 [5.51]

Dimensions

Notes:

1. Dimensioning and tolerancing per ASME Y14.5M-1994.

12

2. Dimensions noted are determined at the outermost
extremes of the plastic body exclusive of mold flash,

11

tie bar burrs, gate burrs, and interlead flash, but
including any mismatch between the top and bottom of
the plastic body. Maximum mold protrusion is 0.007

10

0.321 [8.15]

9

[0.18] per side.

3. Dimensions noted are inclusive of plating thickness.

4. Does not include interlead flash or protrusions.

5. Controlling dimensions in inches [mm].

8

6. Datums A and B to be determined at Datum H.

7. Exposed pad is nominally located at the centerline of

7

Datums A and B. “Max” dimensions noted include both
size and positional tolerances.

0.429 [10.90]

0.028 [0.71]
Ref.

3

0.016 [0.41]

0.011 [0.28]
11×

0.020 [0.51]
Ref.

0.049 [1.23]

0.046 [1.16]

0.019 [0.48]
Ref.

0.022 [0.56]
Ref.

PI-5748a-100311

24

Rev. A 09/12

www.powerint.com

TNY284-290

Part Ordering Information

TNY 288 P G - TL

www.powerint.com

• TinySwitch Product Family

• Series Number

• Package Identier

P Plastic DIP-8C

D SO-8C

K eSOP-12B

• Lead Finish

G RoHS compliant and Halogen Free

• Tape & Reel and Other Options

Blank Standard Configuration

TL Tape & Reel, 1000 pcs min./mult.

25

Rev. A 09/12

Revision Notes Date

A Code A data sheet. 09/12

For the latest updates, visit our website: www.powerint.com

Power Integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability. Power
Integrations does not assume any liability arising from the use of any device or circuit described herein. POWER INTEGRATIONS MAKES
NO WARRANT Y HEREIN AND SPECIFICALLY DISCLAIMS ALL WARRANTIES INCLUDING, WITHOUT LIMITATION, THE IMPLIED
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT OF THIRD PARTY RIGHTS.

Patent Information

The products and applications illustrated herein (including transformer construction and circuits external to the products) may be covered
by one or more U.S. and foreign patents, or potentially by pending U.S. and foreign patent applications assigned to Power Integrations. A
complete list of Power Integrations patents may be found at www.powerint.com. Power Integrations grants its customers a license under
certain patent rights as set forth at http://www.powerint.com/ip.htm.

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POWER INTEGRATIONS PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR
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