Datasheet FSL136MR Datasheet (Fairchild)

FSL136MR Green Mode Fairchild Power Switch (FPS™)

FSL136MR — Green Mode Fairchild Power Switch (FPS™)

June 2010

Features

 Internal Avalanche-Rugged SenseFET (650V)  Under 50mW Standby Power Consumption at

, No-load Condition with Burst Mode

265V

AC

 Precision Fixed Operating Frequency with

Frequency Modulation for Attenuating EMI

 Internal Startup Circuit  Built-in Soft-Start: 15ms  Pulse-by-Pulse Current Limiting  Various Protections: Over-Voltage Protection

(OVP), Overload Protection (OLP), Output-Short Protection (OSP), Abnormal Over-Current Protection (AOCP), Internal Thermal Shutdown Function with Hysteresis (TSD)

 Auto-Restart Mode  Under-Voltage Lockout (UVLO)  Low Operating Current: 1.8mA  Adjustable Peak Current Limit

Applications

 SMPS for VCR, STB, DVD, & DVCD Players  SMPS for Home Appliance  Adapter

Related Resources

AN-4137 — Design Guidelines for Off-line Flyback



Converters using FPS™

 AN-4141 — Troubleshooting and Design Tips for

Fairchild Power Switch (FPS™) Flyback Applications

 AN-4147 — Design Guidelines for RCD Snubber of

Flyback

Description

The FSL136MR integrated Pulse Width Modulator (PWM) and SenseFET is specifically designed for highperformance offline Switch-Mode Power Supplies (SMPS) with minimal external components. FSL136MR includes integrated high-voltage power switching regulators that combine an avalanche-rugged SenseFET with a current-mode PWM control block.

The integrated PWM controller includes: Under-Voltage Lockout (UVLO) protection, Leading-Edge Blanking (LEB), a frequency generator for EMI attenuation, an optimized gate turn-on/turn-off driver, Thermal Shutdown (TSD) protection, and temperaturecompensated precision current sources for loop compensation and fault protection circuitry. The FSL136MR offers good soft-start performance. When compared to a discrete MOSFET and controller or RCC switching converter solution, the FSL136MR reduces total component count, design size, and weight; while increasing efficiency, productivity, and system reliability. This device provides a basic platform that is well suited for the design of cost-effective flyback converters.

Maximum Output Power

230VAC ± 15%

Adapter

Notes:

1. The junction temperature can limit the maximum

2. 230V

3. Typical continuous power in a non-ventilated

(3)

19W 26W 14W 20W

output power.

or 100/115VAC with doubler.

AC

enclosed adapter measured at 50°C ambient.

(2)

85-265VAC

Open

Frame

Adapter

(1)

(3)

Open

Frame

Ordering Information

Part Number

FSL136MR -40 to +105°C FSL136MR 8-Lead, Dual Inline Package (DIP) Rail

Operating

Temperature Range

Top Mark Package Packing Method

n

V

Typical Application Diagram

FSL136MR — Green Mode Fairchild Power Switch (FPS™)

Figure 1. Typical Application

Internal Block Diagram

V

BURL/VBURH

DELAY

V

CC

I

FB

On-Time

Detector

OSP

TSD

V

CC

I

3

FB

I

PK

4

V

SD

V

CC

V

OVP

2.5R

8V/12V

Frequenc y

Generator

R

Start

VCCGood

V

CC

2 6,7,8

VCCGood

STR

5

I

CH

V

REF

Int ernal

Bias

Ra ndom

OSC

SQQ

Soft

PWM

S

R

Q

Gate

Driver

LEB

AOCP

R

Q

V

AOCP

Drai

1

GND

Figure 2. Internal Block Diagram

Pin Configuration

Pin Definitions

FSL136MR — Green Mode Fairchild Power Switch (FPS™)

Figure 3. Pin Configuration

Pin # Name

1 GND

2 VCC

3 VFB

4 IPK

5 V

6, 7, 8 Drain

STR

Description Ground. SenseFET source terminal on the primary side and internal control ground.

Positive Supply Voltage Input. Although connected to an auxiliary transformer winding,

current is supplied from pin 5 (V

reaches the UVLO upper threshold (12V), the internal startup switch opens and device

V

CC

) via an internal switch during startup (see Figure 2). Once

STR

power is supplied via the auxiliary transformer winding. Feedback Voltage. The non-inverting input to the PWM comparator, it has a 0.4mA current

source connected internally, while a capacitor and opto-coupler are typically connected externally. There is a delay while charging external capacitor CFB from 2.4V to 6V using an internal 5µA current source. This delay prevents false triggering under transient conditions, but still allows the protection mechanism to operate under true overload conditions.

Peak Current Limit. Adjusts the peak current limit of the SenseFET. The feedback 0.4mA current source is diverted to the parallel combination of an internal 6k resistor and any

external resistor to GND on this pin to determine the peak current limit.

Startup. Connected to the rectified AC line voltage source. At startup, the internal switch

supplies internal bias and charges an external storage capacitor placed between the VCC pin and ground. Once V

reaches 12V, the internal switch is opened.

CC

Drain. Designed to connect directly to the primary lead of the transformer and capable of

switching a maximum of 650V. Minimizing the length of the trace connecting these pins to the transformer decreases leakage inductance.

FSL136MR — Green Mode Fairchild Power Switch (FPS™)

Absolute Maximum Ratings

Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only. T

Symbol Parameter Min. Max. Unit

V

STR

VDS Drain Pin Voltage -0.3 650.0 V

VCC Supply Voltage 26 V

VFB Feedback Voltage Range -0.3 12.0 V

ID Continuous Drain Current 3 A

IDM Drain Current Pulsed

EAS Single Pulsed Avalanche Energy

PD Total Power Dissipation 1.5 W

TJ Operating Junction Temperature Internally Limited °C

TA Operating Ambient Temperature -40 +105 °C

T

Storage Temperature -55 +150 °C

STG

ESD

ΘJA

ΘJC

ΘJT

Notes:

4. Repetitive rating: pulse width limited by maximum junction temperature.

5. L=51mH, starting T

6. Meets JEDEC standards JESD 22-A114 and JESD 22-C101.

7. All items are tested with the standards JESD 51-2 and JESD 51-10.

8. Θ

9. Θ

free-standing, with no heat-sink, under natural convection.

JA

junction-to-lead thermal characteristics under ΘJA test condition. TC is measured on the source #7 pin closed

JC

to plastic interface for Θ

10. Θ

junction-to-top of thermal characteristic under ΘJA test condition. Tt is measured on top of package. Thermo-

JT

couple is mounted in epoxy glue.

Pin Voltage -0.3 650.0 V

STR

(4)

12 A

(5)

230 mJ

Human Body Model, JESD22-A114

Charged Device Model, JESD22-C101

Junction-to-Ambient Thermal Resistance

Junction-to-Case Thermal Resistance

Junction-to-Top Thermal Resistance

=25°C.

J

thermo-couple mounted on soldering.

JA

(6)

5.0

(6)

1.5

(7,8)

(7,9)

19 °C/W

(7,10)

33.7 °C/W

= 25°C, unless otherwise specified.

J

KV

80 °C/W

Electrical Characteristics

TA = 25°C unless otherwise specified.

Symbol Parameter Conditions Min. Typ. Max. Units

SenseFET Section

BV

Drain-Source Breakdown Voltage VCC = 0V, ID = 250µA 650 V

DSS

I

Zero Gate Voltage Drain Current VDS = 650V, VGS = 0V 250 µA

DSS

R

Drain-Source On-State Resistance VGS = 10V, VGS = 0V, TC = 25°C 3.5 4.0 

DS(ON)

C

Input Capacitance VGS = 0V, VDS = 25V, f = 1MHz 290 pF

ISS

C

Output Capacitance VGS = 0V, VDS = 25V, f = 1MHz 45 pF

OSS

C

Reverse Transfer Capacitance VGS = 0V, VDS = 25V, f = 1MHz 5.5 pF

RSS

t

Turn-On Delay VDD = 350V, ID = 3.5A 12 ns

d(ON)

tr Rise Time VDD = 350V, ID = 3.5A 22 ns

t

Turn-Off Delay VDD = 350V, ID = 3.5A 20 ns

d(OFF)

tf Fall Time VDD = 350V, ID = 3.5A 19 ns

Control Section

f

Switching Frequency VDS = 650V, VGS = 0V 61 67 73 KHz

OSC

f

Switching Frequency Variation VGS = 10V, VGS = 0V, TC = 125°C ±5 ±10 %

OSC

fFM Frequency Modulation ±3 KHz

D

Maximum Duty Cycle VFB = 4V 71 77 83 %

MAX

D

Minimum Duty Cycle VFB = 0V 0 0 0 %

MIN

V

START

V

UVLO Threshold Voltage

After Turn-On 7 8 9 V

STOP

IFB Feedback Source Current VFB = 0V 320 400 480 µA

t

Internal Soft-Start Time VFB = 4V 10 15 20 ms

S/S

Burst Mode Section

V

BURH

V

0.25 0.35 0.45 V

Burst Mode Voltage T

BURL

V

150 mV

BUR(HYS)

Protection Section

I

Peak Current Limit TJ = 25°C, di/dt = 300mA/µs 1.89 2.15 2.41 A

LIM

t

Current Limit Delay Time

CLD

(11)

200 ns

VSD Shutdown Feedback Voltage VCC = 15V 5.5 6.0 6.5 V

I

Shutdown Delay Current VFB = 5V 3.5 5.0 6.5 µA

DELAY

V

Over-Voltage Protection Threshold VFB = 2V 22.5 24.0 25.5 V

OVP

11 12 13 V

0.4 0.5 0.6 V

= 25°C

J

FSL136MR — Green Mode Fairchild Power Switch (FPS™)

t

OSP

V

t

OSP_FB

V

TSD

HYS

t

Output-Short

OSP

Protection

(11)

AOCP Voltage

AOCP

Thermal Shutdown

Hysteresis 60 °C

TSD

Leading-Edge Blanking Time

LEB

(11)

Threshold Time

T

= 25°C

J

Threshold Feedback Voltage

Feedback Blanking

OSP Triggered When t V

FB>VOSP

t

OSP_FB

and Lasts Longer than

Time

(11)

T

Shutdown Temperature

(11)

300 ns

= 25°C 0.85 1.00 1.15 V

J

125 137 150 °C

ON<tOSP

1.00 1.35 µs

,

1.44 1.60 V

2.0 2.5 µs

Continued on the following page…

Electrical Characteristics (Continued)

TA = 25°C unless otherwise specified.

Symbol Parameter Conditions Min. Typ. Max. Units

Total Device Section

I

Operating Supply Current

OP1

(While Switching)

Operating Supply Current

OP2

(Control Part Only)

ICH Startup Charging Current VCC = 0V 0.90 1.10 1.30 mA

V

Minimum V

STR

Supply Voltage VCC = VFB = 0V, V

STR

Note:

11. Though guaranteed by design, it is not 100% tested in production.

(11)

VCC = 14V, VFB > V

VCC = 14V, VFB < V

2.5 3.5 mA

BURH

1.8 2.5 mA

BURL

Increase 35 V

STR

FSL136MR — Green Mode Fairchild Power Switch (FPS™)

Typical Performance Characteristics

These characteristic graphs are normalized at TA=25.

FSL136MR — Green Mode Fairchild Power Switch (FPS™)

OperatingFrequency(f

1.4

1.3

1.2

1.1

1

0.9

0.8

0.7

0.6

‐40Ԩ ‐25Ԩ 0 Ԩ 25Ԩ 50Ԩ 75Ԩ 100Ԩ 120Ԩ 140Ԩ

OSC

)

1.4

1.3

1.2

1.1

1

0.9

0.8

0.7

0.6

‐40Ԩ ‐25Ԩ 0Ԩ 25Ԩ 50Ԩ 75Ԩ 100Ԩ 120Ԩ 140Ԩ

MaximumDutyCycle(D

MAX

)

Figure 4. Operating Frequency vs. Temperature Figure 5. Maximum Duty Cycle vs. Temperature

OperatingSupplyCurrent(I

1.4

1.3

1.2

1.1

1.0

0.9

0.8

0.7

0.6

‐40 ‐25 0 255075100120140

op2

)

StartThresholdVoltage(V

1.4

1.3

1.2

1.1

1.0

0.9

0.8

0.7

0.6

‐40 ‐25 0 25 50 75 100 120 140

START

)

Figure 6. Operating Supply Current vs. Temperature Figure 7. Start Threshold Voltage vs. Temperature

StopThresholdVoltage(V

1.4

1.3

1.2

1.1

1.0

0.9

0.8

0.7

0.6

‐40 ‐25 0 25 50 75 100 120 140

STOP

)

1.4

1.3

1.2

1.1

1

0.9

0.8

0.7

0.6

‐40

FeedbackSourceCurrent(IFB)

Ԩ

‐25Ԩ0Ԩ25Ԩ50Ԩ75Ԩ100Ԩ120Ԩ140

Ԩ

Figure 8. Stop Threshold Voltage vs. Temperature Figure 9. Feedback Source Current vs. Temperature

Typical Performance Characteristics (Continued)

These characteristic graphs are normalized at TA=25.

FSL136MR — Green Mode Fairchild Power Switch (FPS™)

StartupChargingCurrent(ICH)

1.4

1.3

1.2

1.1

1

0.9

0.8

0.7

0.6

‐40Ԩ ‐25Ԩ 0Ԩ 25Ԩ 50Ԩ 75Ԩ 100Ԩ 120Ԩ 14 0 Ԩ

PeakCurrentLimit(I

1.4

1.3

1.2

1.1

1

0.9

0.8

0.7

0.6

‐40Ԩ ‐25Ԩ 0Ԩ 25Ԩ 50Ԩ 75Ԩ 100Ԩ 120Ԩ 140Ԩ

LIM

)

Figure 10. Startup Charging Current vs. Temperature Figure 11. Peak Current Limit vs. Temperature

BurstOperatingSupplyCurrent(I

1.4

1.3

1.2

1.1

1.0

0.9

0.8

0.7

0.6

‐40 ‐25 0 255075100120140

Figure 12. Burst Operating Supply Current

vs. Temperature

op1

)

1.4

1.3

1.2

1.1

1

0.9

0.8

0.7

0.6

‐40Ԩ ‐25Ԩ 0 Ԩ 25Ԩ 50Ԩ 75Ԩ 100Ԩ 120Ԩ 140Ԩ

Over‐VoltageProtection(V

OVP

)

Figure 13. Over-Voltage Protection

vs. Temperature

Functional Description

FSL136MR — Green Mode Fairchild Power Switch (FPS™)

Startup

At startup, an internal high-voltage current source supplies the internal bias and charges the external capacitor (C in Figure 14. When V

) connected with the VCC pin, as illustrated

A

reaches the start voltage of

CC

12V, the FPS™ begins switching and the internal highvoltage current source is disabled. The FPS continues normal switching operation and the power is provided from the auxiliary transformer winding unless V

goes

CC

below the stop voltage of 8V.

Figure 14. Startup Circuit

Oscillator Block

The oscillator frequency is set internally and the FPS has a random frequency fluctuation function. Fluctuation of the switching frequency of a switched power supply can reduce EMI by spreading the energy over a wider frequency range than the bandwidth measured by the EMI test equipment. The amount of EMI reduction is directly related to the range of the frequency variation. The range of frequency variation is fixed internally; however, its selection is randomly chosen by the combination of external feedback voltage and internal free-running oscillator. This randomly chosen switching frequency effectively spreads the EMI noise nearby switching frequency and allows the use of a cost-effective inductor instead of an AC input line filter to satisfy the world-wide EMI requirements.

Figure 15. Frequency Fluctuation Waveform

Feedback Control

FSL136MR employs current-mode control, as shown in Figure 16. An opto-coupler (such as the FOD817A) and shunt regulator (such as the KA431) are typically used to implement the feedback network. Comparing the feedback voltage with the voltage across the R

SENSE

resistor makes it possible to control the switching duty cycle. When the shunt regulator reference pin voltage exceeds the internal reference voltage of 2.5V, the opto-coupler LED current increases, the feedback voltage V

is pulled down, and the duty cycle is

FB

reduced. This typically occurs when the input voltage is increased or the output load is decreased.

Figure 16. Pulse-Width-Modulation Circuit

Leading-Edge Blanking (LEB)

At the instant the internal SenseFET is turned on, the primary-side capacitance and secondary-side rectifier diode reverse recovery typically cause a high-current spike through the SenseFET. Excessive voltage across the R operation in the current-mode PWM control. To counter this effect, the FPS employs a leading-edge blanking (LEB) circuit (see the Figure 16). This circuit inhibits the PWM comparator for a short time (t SenseFET is turned on.

Protection Circuits

The FPS has several protective functions, such as overload protection (OLP), over-voltage protection (OVP), output-short protection (OSP), under-voltage lockout (UVLO), abnormal over-current protection (AOCP), and thermal shutdown (TSD). Because these various protection circuits are fully integrated in the IC without external components, the reliability is improved without increasing cost. Once a fault condition occurs, switching is terminated and the SenseFET remains off. This causes V stop voltage, V internal high-voltage current source charges the V capacitor via the V start voltage, V operation. In this manner, the auto-restart can alternately enable and disable the switching of the power SenseFET until the fault condition is eliminated.

resistor leads to incorrect feedback

SENSE

) after the

LEB

to fall. When VCC reaches the UVLO

CC

(8V), the protection is reset and the

STOP

pin. When VCC reaches the UVLO

STR

(12V), the FPS resumes normal

START

CC

Figure 17. Auto-Restart Protection Waveforms

Overload Protection (OLP)

Overload is defined as the load current exceeding a pre-set level due to an unexpected event. In this situation, the protection circuit should be activated to protect the SMPS. However, even when the SMPS is operating normally, the overload protection (OLP) circuit can be activated during the load transition or startup. To avoid this undesired operation, the OLP circuit is designed to be activated after a specified time to determine whether it is a transient situation or a true overload situation.

In conjunction with the I

current limit pin (if used), the

PK

current-mode feedback path limits the current in the SenseFET when the maximum PWM duty cycle is attained. If the output consumes more than this maximum power, the output voltage (V

) decreases

O

below its rating voltage. This reduces the current through the opto-coupler LED, which also reduces the opto-coupler transistor current, thus increasing the feedback voltage (V

). If VFB exceeds 2.4V, the

FB

feedback input diode is blocked and the 5µA current source (I condition, V

) slowly starts to charge CFB. In this

DELAY

increases until it reaches 6V, when the

FB

switching operation is terminated, as shown in Figure

18. The shutdown delay is the time required to charge C

from 2.4V to 6V with 5µA current source.

FB

Abnormal Over-Current Protection (AOCP)

When the secondary rectifier diodes or the transformer pin are shorted, a steep current with extremely high di/dt can flow through the SenseFET during the LEB time. Even though the FPS has OLP (Overload Protection), it is not enough to protect the FPS in that abnormal case, since severe current stress is imposed on the SenseFET until OLP triggers. The FPS includes the internal AOCP (Abnormal Over-Current Protection) circuit shown in Figure 19. When the gate turn-on signal is applied to the power SenseFET, the AOCP block is enabled and monitors the current through the sensing resistor. The voltage across the resistor is compared with a preset AOCP level. If the sensing resistor voltage is greater than the AOCP level, the set signal is applied to the latch, resulting in the shutdown of the SMPS.

Figure 19. Abnormal Over-Current Protection

Thermal Shutdown (TSD)

The SenseFET and the control IC are integrated, making it easier to detect the temperature of the SenseFET. When the temperature exceeds approximately 137°C, thermal shutdown is activated.

Over-Voltage Protection (OVP)

In the event of a malfunction in the secondary-side feedback circuit or an open feedback loop caused by a soldering defect, the current through the opto-coupler transistor becomes almost zero. Then, V

climbs up in

FB

a similar manner to the overload situation, forcing the preset maximum current to be supplied to the SMPS until the overload protection is activated. Because excess energy is provided to the output, the output voltage may exceed the rated voltage before the overload protection is activated, resulting in the breakdown of the devices in the secondary side. To prevent this situation, an over-voltage protection (OVP) circuit is employed. In general, V output voltage and the FPS uses V monitoring the output voltage. If V

is proportional to the

CC

instead of directly

CC

exceeds 24V, OVP

CC

circuit is activated, resulting in termination of the switching operation. To avoid undesired activation of OVP during normal operation, V

should be designed

CC

to be below 24V.

FSL136MR — Green Mode Fairchild Power Switch (FPS™)

Output-Short Protection (OSP)

If the output is shorted, the steep current with extremely high di/dt can flow through the SenseFET during the LEB time. Such a steep current brings high-voltage

Figure 18. Overload Protection (OLP)

stress on the drain of SenseFET when turned off. To protect the device from such an abnormal condition, OSP detects V V

is higher than 1.6V and the SenseFET turn-on time

FB

and SenseFET turn-on time. When the

FB

A

=

is lower than 1.0µs, the FPS recognizes this condition as an abnormal error and shuts down PWM switching until V

reaches V

CC

again. An abnormal condition

START

output is shown in Figure 20.

Figure 20. Output Short Waveforms (OSP)

FSL136MR — Green Mode Fairchild Power Switch (FPS™)

Soft-Start

The FPS has an internal soft-start circuit that slowly increases the feedback voltage, together with the SenseFET current, after it starts. The typical soft-start time is 15ms, as shown in Figure 21, where progressive increments of the SenseFET current are allowed during the startup phase. The pulse width to the power switching device is progressively increased to establish the correct working conditions for transformers, inductors, and capacitors. The voltage on the output capacitors is progressively increased with the intention of smoothly establishing the required output voltage. Soft-start helps prevent transformer saturation and reduce the stress on the secondary diode.

Figure 21. Internal Soft-Start

Figure 22. Burst-Mode Operation

Adjusting Peak Current Limit

As shown in Figure 23, a combined 6k internal resistance is connected to the non-inverting lead on the PWM comparator. An external resistance of Rx on the current limit pin forms a parallel resistance with the 6k when the internal diodes are biased by the main current source of 400µA. For example, FSL136MR has a typical SenseFET peak current limit (I adjusted to 1.5A by inserting Rx between the I the ground. The value of the Rx can be estimated by the following equations:

XkΩ:6kΩ1.5A:2.15

=

6kΩ||RxX

where X is the resistance of the parallel network.

) of 2.15A. I

LIM

can be

LIM

pin and

PK

(1)

(2)

Burst Operation

To minimize power dissipation in standby mode, the FPS enters burst mode. As the load decreases, the feedback voltage decreases. As shown in Figure 22, the device automatically enters burst mode when the feedback voltage drops below V continues until the feedback voltage drops below V

. Switching

BURH

BURL

.

Figure 23. Peak Current Limit Adjustment

At this point, switching stops and the output voltages drop at a rate dependent on standby current load. This causes the feedback voltage to rise. Once it passes V

, switching resumes. The feedback voltage then

BURH

falls and the process repeats. Burst mode alternately enables and disables switching of the SenseFET and reduces switching loss in standby mode.

Physical Dimensions

FSL136MR — Green Mode Fairchild Power Switch (FPS™)

9.83

9.00

6.67

6.096

8.255

7.61

5.08 MAX

0.33 MIN

(0.56)

2.54

7.62

0.56

0.355

3.60

3.00

1.65

1.27

3.683

3.20

0.356

0.20

7.62

9.957

7.87

NOTES: UNLESS OTHERWISE SPECIFIED

A) THIS PACKAGE CONFORMS TO

JEDEC MS-001 VARIATION BA

B) ALL DIMENSIONS ARE IN MILLIMETERS.

C) DIMENSIONS ARE EXCLUSIVE OF BURRS,

MOLD FLASH, AND TIE BAR EXTRUSIONS.

D) DIMENSIONS AND TOLERANC

ES PER

ASME Y14.5M-1994

E) DRAWING FILENAME AND REVSION: MKT-N08FREV2.

Figure 24. 8-Lead, Dual Inline Package (DIP)

Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or obtain the most rece nt re vision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the warranty therein, which covers Fairchild products.

Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings:

http://www.fairchildsemi.com/packaging/

.

FSL136MR — Green Mode Fairchild Power Switch (FPS™)