HIT HA17384HPS, HA17384EPS, HA17384DPS, HA17385HPS, HA17384SPS Datasheet

HA17384SPS/SRP, HA17384HPS/HRP,

HA17385HPS/HRP

High Speed Current Mode PWM Control IC

for Switching Power Supply

ADE-204-028A (Z)

2nd Edition

Nov. 1999

Description

The HA17384S/H and HA17385H are PWM control switching regulator IC series suitable for highspeed,
current-mode switching power supplies. With ICs from this series and a few external parts, a small, low
cost flyback-transformer switching power supply can be constructed, which facilitates good line regulation
by current mode control. Synchronous operation driven after an external signal can also be easily obtained
which offers various applications such as a power supply for monitors small multi-output power supply.

The IC series are composed of circuits required for a switching regulator IC. That is a under-voltage
lockout (UVL), a high precision reference voltage regulator (5.0 V ± 2%), a triangular wave oscillator for
timing generation, a high-gain error amplifier, and as totem pole output driver circuit which directly drives
the gate of power MOSFETs found in main switching devices. In addition, a pulse-by-pulse type, high­speed, current-detection comparator circuit with variable detection level is incorporated which is required
for current mode control.

The HA17384SPS includes the above basic function circuits. In addition to these basic functions, the H
Series incorporates thermal shut-down protection (TSD) and overvoltage protection (OVP) functions, for
configuration of switching power supplies that meet the demand for high safety levels.

Between the HA17384 and HA17385, only the UVL threshold voltages differ as shown in the product
lineup table.(See next page.)

This IC is pin compatible with the “3842 family” ICs made by other companies in the electronics industry.
However, due to the characteristics of linear ICs, it is not possible to achieve ICs that offer full
compatibility in every detail.

Therefore, when using one of these ICs to replace another manufacturer’s IC, it must be recognized that it
has different electrical characteristics, and it is necessary to confirm that there is no problem with the power
supply (mounting) set used.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

2

Functions

• Under-voltage lockout system

• Reference voltage regulator of 5.0 V ± 2%

• Triangular wave (sawtooth) oscillator

• Error amplifier

• Totem pole output driver circuit (direct driving for power MOSFETs)

• Current-detection comparator circuit for current mode

• OVP function (over voltage protection) *

1

• TSD function (thermal shut-down protection) *

1

• Protect function by zener diode (between power input and GND)
Note: 1. H series only.

Features

• High-safety UVL circuit is used (Both VIN and Vref are monitored)

• High speed operation:
 Current detection response time: 100 ns Typ
 Maximum oscillation frequency: 500 kHz

• Low standby current: 170 µA Typ

• Wide range dead band time

(Discharge current of timing capacitance is constant 8.4 mA Typ)

• Able to drive power MOSFET directly
(Absolute maximum rating of output current is ±1 A peak)

• OVP function (over voltage protection) is included *

1

(Output stops when FB terminal voltage is 7.0 V Typ or higher)

• TSD function (thermal shut-down protection) is included *

1

(Output stops when the temperature is 160°C Typ or higher)

• Zener protection is included
(Clamp voltage between VIN and GND is 34 V Typ)

• Wide operating temperature range:
 Operating temperature: –20°C to +105°C
 Junction temperature: 150°C *

2

Note: 1. H series only.

2. S series only.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

3

Product Line-up

Package Additional Function

UVL Power Supply
Threshold Voltage

DILP8 (DP-8) SOP8 (FP-8DC)

TSD
(Thermal shut­down protection)

OVP
(Over voltage
protection) V

TH UVL

(V) Typ V

TL UVL

(V) Typ

HA17384SPS HA17384SRP — — 16.0 10.0
HA17384HPS HA17384HRP ❍❍
HA17385HPS HA17385HRP ❍❍8.4 7.6

Pin Arrangement

1

2

3

4

8

7

6

5

COMP

FB

CS

R

T/CT

Vref

V

IN

OUT

GND

(Top view)

Pin Function

Pin No. Symbol Function Note

1 COMP Error amplifier output pin
2 FB Inverting input of error amp./OVP input pin 1
3 CS Current sensing signal input pin
4R

T

/C

T

Timing resistance, timing capacitance connect pin
5 GND Groung pin
6 OUT PWM Pulse output pin
7VINPower supply voltage input pin
8 Vref Reference voltage 5V output pin

Note: 1. Overvoltage protection (OVP) input is usable only for the HA17384H and HA17385H.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

4

Block Diagram

Oscillator

Totem pole
output circuit

Note: 1. Blocks with bold line are not included in HA17384SPS/SRP.

0.8mA

EA

−

+

OVP

−

+

CS

−

+

7.0V

UVL1

H

L

VL

VH

UVL2

Vref > 4.7VR

Q

S

6.5V

1
2

Vref

(2.5V)

*1

2V

F

160°C

2R

R

1V

R
S

Q

PWM LOGIC

Vref

NOR

8.4 mA

1.2V

+

−

OR

34V

1

2

3

4

8

7

6

COMP

FB

(OVP input)

CS

RT/CT

Vref

V

IN

OUT

5 GND

2.8 V

OUT

5V band
gap
reference
regulator

OVP
latch

TSD

sense

CS

latch

Latch set

pulse

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

5

Absolute Maximum Ratings

Item Symbol Rating Unit Note

Supply voltage V

IN

30 V

DC output current I

O

±0.1 A

Peak output current I

O PEAK

±1.0 A

Error amplifier input voltage V

FB

–0.3 to V

IN

V

COMP terminal input voltage V

COMP

–0.3 to +7.5 V

Error output sink current I

OEA

10 mA

Power dissipation P

T

680 mW 1, 2
Operating temperature Topr –20 to +105 °C
Junction temperature Tj 125 °C3

150 °C4
Storage temperature Tstg –55 to +125 °C3

–55 to +150 °C4
Notes: 1. For the HA17384HPS and HA17385HPS,

This value applies up to Ta = 43°C; at temperatures above this, 8.3 mW/°C derating should be

applied.
For the HA17384SPS,
This value applies up to Ta = 68°C; at temperatures above this, 8.3 mW/°C derating should be

applied.

Power Dissipation P

T

(mW)

Ambient Temperature Ta (°C)

680mW

374mW

43°C 68°C 150°C

800

600

400

200

0

−20 0 20 40 60 80 100 120 140 160

166mW

105°C 125°C

HA17384SPS

HA17384HPS, HA17385HPS

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

6

Absolute Maximum Ratings (cont)

Notes: 2. This is the value when the device is mounted on a glass-epoxy substrate (40 mm × 40 mm × 1.6

mm). However,
For the HA17384HRP and HA17385HRP,
Derating should be performed with 8.3 mW/°C in the Ta ≥ 43°C range if the substrate wiring

density is 10%.
Derating should be performed with 11.1 mW/°C in the Ta ≥ 63°C range if the substrate wiring

density is 30%.
For the HA17384SRP,
Derating should be performed with 8.3 mW/°C in the Ta ≥ 68°C range if the substrate wiring

density is 10%.
Derating should be performed with 11.1 mW/°C in the Ta ≥ 89°C range if the substrate wiring

density is 10%.

Power Dissipation P

T

(mW)

Ambient Temperature Ta (°C)

374 mW

680 mW

43°C63°C

150°C89°C

800

600

400

200

0

−20 0 20 40 60 80 100 120 140 160

166 mW

500 mW

222 mW

68°C 105°C 125°C

HA17384SRP
: −11.1 mW/°C (wiring density is 30%)
: −8.3 mW/°C (wiring density is 10%)
HA17384HRP, HA17385HRP
: −11.1 mW/°C (wiring density is 30%)
: −8.3 mW/°C (wiring density is 10%)

3. Applies to the HA17384HPS/HRP and HA17385HPS/HRP.

4. Applies to the HA17384SPS/SRP.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

7

Electrical Characteristics

(The condition is: Ta = 25°C, VIN = 15 V, CT = 3300 pF, RT = 10 kΩ without notice)

Reference Part

Item Symbol Min Typ Max Unit Test Condition Note

Reference output voltage Vref 4.9 5.0 5.1 V Io = 1 mA
Line regulation Regline — 20 50 mV 12 V ≤ V

IN

≤ 25 V
Load regulation Regload — 10 25 mV –1 mA ≥ Io ≥ –20 mA
Output short current los –30 –100 –180 mA Vref = 0V
Temperature stability ∆Vref — 80 — ppm/°C Io = –1 mA,

–20°C ≤ Ta ≤ 105°C

1

Output noise voltage V

N

— 100 — µV 10 Hz ≤ fnoise ≤ 10 kHz 1

Notes: 1. Reference value for design.

Triangular Wave Oscillator Part

Item Symbol Min Typ Max Unit Test Condition Note

Typical oscillating frequency fosc Typ 47 52 57 kHz C

T

= 3300 pF,

R

T

= 10 kΩ

Maximum oscillating
frequency

fosc Max 500 — — kHz

Supply voltage dependency of
oscillating frequency

∆fosc 1 — ±0.5 ±2.0 % 12 V ≤ VIN ≤ 25 V

Temperature dependency of
oscillating frequency

∆fosc 2 — ±5.0 — % –20°C ≤ Ta ≤ 105°C1

Discharge current of C

T

Isink

CT

7.5 8.4 9.3 mA VCT = 2.0 V

Low level threshold voltage V

TLCT

— 1.2 — V 1

High level threshold voltage V

THCT

— 2.8 — V 1

Triangular wave amplitude ∆V

CT

— 1.6 — V ∆VCT = V

THCT

– V

TLCT

1

Notes: 1. Reference value for design.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

8

Electrical Characteristics (cont)

Error Amplifire Part / OVP Part

Item Symbol Min Typ Max Unit Test Condition Note

Non-inverting input voltage V

FB

2.42 2.50 2.58 V V

COMP

= 2.5 V

Input bias current I

IB

— –0.2 –2.0 µAVFB = 5.0 V

Open loop voltage gain A

VOL

65 90 — dB 2.0 V ≤ VO ≤ 4.0 V
Unity gain bank width BW 0.7 1.0 — MHz
Power supply voltage

rejection ratio

PSRR 60 70 — dB 12 V ≤ VIN ≤ 25 V

Output sink current I

Osink EA

3.0 9.0 — mA VFB = 2.7 V, V

COMP

= 1.1 V

Output source current I

Osource EA

–0.5 –0.8 — mA VFB = 2.3 V, V

COMP

= 5.0 V

High level output voltage V

OH EA

5.5 6.5 7.5 V VFB = 2.3 V,
R

L

= 15 kΩ(GND)

Low level output voltage V

OL EA

— 0.7 1.1 V VFB = 2.7 V,

R

L

= 15 kΩ(Vref)

OVP latch threshold
voltage

V

OVP

6.0 7.0 8.0 V Increase FB terminal
voltage

1

OVP (FB) terminal input
current

I

FB(OVP)

—3050µAVFB = 8.0 V 1

OVP latch reset VIN voltage V

IN(OVP RES)

6.0 7.0 8.0 V Decreasing VIN after OVP
latched

1

Note: 1. These values are not prescribe to the HA17384SPS/SRP because OVP function is not included.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

9

Electrical Characteristics (cont)

Current Sensing Part

Item Symbol Min Typ Max Unit Test Condition Note

Voltage gain A

VCS

2.85 3.00 3.15 V/V VFB = 0 V 1

Maximum sensing voltage Vth

CS

0.9 1.0 1.1 V

Power supply voltage
rejection ratio

PSRR — 70 — dB 12 V ≤ VIN ≤ 25 V 2

Input bias current I

BCS

— –2 –10 µAVCS = 2 V

Current sensing
response time

tpd 50 100 150 ns Time from when V

CS

becomes 2 V to when
output becomes “L” (2 V)

3

Notes: 1. The gain this case is the ratio of error amplifier output change to the current-sensing threshold

voltage change.

2. Reference value for design.

3. Current sensing response time tpd is definded a shown in the figure 1.

V

CS

V

OUT

(PWM)

Vth

tpd

Figure 1 Definition of Current Sensing Response Time tpd

PWM Output Part

Item Symbol Min Typ Max Unit Test Condition Note

Output low voltage 1 V

OL1

— 0.7 1.5 V losink = 20 mA

Output low voltage 2 V

OL2

— 1.5 2.2 V losink = 200 mA 1

Output high voltage 1 V

OH1

13.0 13.5 — V losource = –20 mA

Output high voltage 2 V

OH2

12.0 13.3 — V losource = –200 mA 1

Output low voltage at
standby mode

V

OL STB

— 0.8 1.1 V VIN = 5 V,

losink = 1 mA

Rise time t

r

— 80 150 ns CL = 1000 pF

Fall time t

f

— 70 130 ns CL = 1000 pF
Maximum ON duty Du max 94 96 100 %
Minimum ON duty Du min — — 0 %

Notes: 1. Pulse application test

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

10

Electrical Characteristics (cont)

UVL Part

Item Symbol Min Typ Max Unit Test Condition Note

Threshold voltage for V

TH UVL

14.5 16.0 17.5 V Turn-ON voltage 1
high VIN level 7.6 8.4 9.2 V when VIN is rising 2
Threshold voltage for V

TL UVL

9.0 10.0 11.0 V Minimum operating 1
low VIN level 6.8 7.6 8.4 V voltage after turn-ON 2
V

IN

UVL hysteresis voltage V

HYS UVL

5.0 6.0 7.0 V V

HYS UVL

= V

TH UVL

– V

TL UVL

1

0.6 0.8 1.0 V 2
Vref UVL threshold voltage V

T Vref

4.3 4.7 Vref V Voltage is forced toVref

terminal

Notes: 1. For the HA17384S/H.

2. For the HA17385H.

Total Characteristics

Item Symbol Min Typ Max Unit Test Condition Note

Operating current I

IN

7.0 10.0 13.0 mA CL = 1000 pF, VFB = VCS = 0 V

Standby current I

STBY

120 170 230 µA Current at start up

Current of latch I

LATCH

200 270 340 µAV

FB

= 0 V after VFB = V

OVP

1, 2

Power supply zener
voltage

V

INZ

31 34 37 V IIN + 2.5 mA

Overheat protection
starting temperature

Tj

TSD

— 160 — °C 3, 4

Notes: 1. These values are not prescribe to the HA17384SPS/SRP because OVP function is not included.

2. V

IN

= 8.5 V in case of the HA17384H.

2. These values are not prescribe to the HA17384SPS/SRP because TSD function is not included.

4. Reference value for design.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

11

Timing Chart

Waveform timing (Outline)Signal Name

Input voltage
V

IN

Pin 7

UVL1
Internal signal which
cannot be externally
monitored.

Reference voltage
Vref Pin 8

UVL2
Internal signal which
cannot be externally
monitored.

Oscillation voltage of
triangular wave
R

T/CT

Pin 4

Start up signal
Internal signal which
cannot be externally
monitored.

PWM latch setting signal
internal signal which
cannot be externally
monitored.

Error amplifier input signal
V

FB

Pin 2

Error amplifier output signal
V

COMP

Pin 1

I

D

*

1

OVP latch signal
Internal signal which
cannot be externally
monitored.

Power ON IC turn ON

Stationary operation

OVP input

OVP latched
condition

Power OFF

Reset of
OVP latch

Start up latch
release

( ) shows the case
using HA17385H

PWM output voltage
V

OUT

Pin 6

Note: 1.

I

D

indicates the power MOSFET drain current; it is actually observed as voltage VS generated

by power MOSFET current detection source resistance R

S

.

V

COMP

indicates the error amp output voltage waveform. Current mode operation is

performed so that a voltage 1/3 that of V

COMP

is the current limiter level.

10 V

(7.6 V)

7.0 V
2 V

16 V

(8.4 V)

2 V

0V

0V

0V

0V

0V

0V

0V

0V

0V

0V

0V

5 V

4.7 V

2.8 V

1.2 V

7.0 V typ
(OVP input)

V

COMP

I

D

V

IN

4.7 V

IC operates and
PWM output stops.

This voltage is determined
by the transformer

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

12

Operation (Description of Timing Chart)

From Power ON to Turn On

After the power is switched ON, the power supply terminal voltage (VIN) of this IC rises by charging
through bleeder resistor RB. At this time, when the power voltage is in the range of 2 V to 16 V*1. The
low-voltage, lock out UVL1 operates and accordingly the OUT voltage, that is, the gate voltage of the
power MOSFET, is fixed at 1.3 V or a lower value, resulting in the power MOSFET remaining in the OFF
state.

When the power supply voltage reaches 16 V, UVL1 of this IC is reset and the reference voltage (Vref)
generating part turns ON. However, until Vref becomes 4.7 V, the low-voltage, lock out UVL2 operates to
keep the OUT terminal voltage low. After Vref terminal voltage becomes 4.7 V or higher, OUT terminal
outputs a PWM pulse.

Note: 1. The value is for the HA17384S/H.

The value is 8.4 V for the HA17385H.

Generation of Triangular Wave and PWM Pulse

After the output of the Vref, each blocks begins to operate. The triangular wave is generated on the RT/C

T

terminal. For PWM pulses, the triangular wave rise time is taken as the variable on-duty on-time. The
triangular wave fall time is taken as the dead-band time. The initial rise of the triangular wave starts from 0
V, and to prevent a large on-duty at this time, the initial PWM pulse is masked and not output. PWM
pulses are outputted after the second triangular wave. The above operation is enabled by the charge energy
which is charged through the bleeder resistor RB into the capacitor CB of VIN.

Stationary Operation

PWM pulses are outputted after the second wave of the triangular wave and stationary operation as the
switching power supply starts.

By switching operation from ON/OFF to OFF/ON in the switching device (power MOSFET), the
transformer converts the voltage. The power supply of IC VIN is fed by the back-up winding of the
transformer.

In the current mode of the IC, the current in the switcing device is always monitored by a source resistor
RCS. Then the current limiter level is varied according to the error voltage (COMP terminal voltage) for
PWM control. One third of the error voltage level, which is divided by resistors “2R” and “R” in the IC, is
used to sense the current (R = 25 kΩ).

Two diodes between the error output and the 2R-R circuit act only as a DC level shifter. Actually, these
diodes are connected between the 2R-R circuit and GND, and, the current sensing comparator and GND,
respectively. Therefore, these blocks operate 1.4 V higher than the GND level. Accordingly, the error of the
current sensing level caused by the switching noise on the GND voltage level is eliminated. The zener
diode of 1 V symbolically indicates that the maximum sensing voltage level of the CS terminal is 1 V.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

13

Power OFF

At power OFF, the input voltage of the transformer gradually decreases and then VIN of IC also decreases
according to the input voltage. When VIN becomes lower than 10 V*2 or Vref becomes lower than 4.7 V,
UVL1 (UVL2) operates again and the PWM pulse stops.

Note: 2. The value is for the HA17384S/H.

The value is 7.6 V for the HA17385H.

Commercial AC voltage

Power switch Line filter

Rectifier
bridge diode

DC
output

Floating
ground

Power MOSFET
ex. 2SK1567

SBD

ex. HRP24

OVP input

(Ex: from photocoupler)

20k

3.6k

100µ
200V

1000µ
10V

R

T

10k

V

CS

R

B

220k
1/4W

C

B

10µ

50V

V

IN

0.1µ

51

1k

−

+

B

P

S

HRP32

Vref

V

IN

OUT
GND

COMP

FB

HA17384H,
HA17385H

CS
RT/C

T

+

−

+

−

+

−

+

−

R

CS

1
2W

100p

150k

330p

C

T

3300p

Figure 2 Mounting Circut Diagram for Operation Expression

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

14

V

COMP

COMP terminal
(Error output)

PWM pulse

Latch setting pulse
(Implemented in triagular
wave oscillator)

Latch setting
pulse

V

COMP

Error voltage

V

CS

Current sensing
level

R
S Q

1 V

V

CS

CS terminal

2 R

R

2V

F

×

1

3

−

+

CS

CS

latch

Figure 3 Operation Diagram of Current Sensing Part

Point:

Current Sense Comparator

Threshold Voltage V

CS

(V)

Error Amplifier Output Voltage Vcomp (V)

Light load

Heavy load

1) At maximum rated load, the setting should be made to give
approximately 90% of area A below.

2) When the OVP latch is operated, the setting should be made
in area B or C.

1.0

0.8

0.6

0.4

0.2

0.0
012345678

B

A

C

1.4V

4.4V 7.5V

A : Stationary operation / PWM
(Current-mode operation)
B : Current limit operation / Max duty cycle
C : No sensitivity area / No PWM output

Figure 4 Current Sense Characteristics

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

15

Features and Theory of Current Mode Control

Features of Current Mode Control

• Switch element current detection is performed every cycle, giving a high feedback response speed.

• Operation with a constant transformer winding current gives a highly stable output voltage (with

excellent line regulation characteristics, in particular).

• Suitable for flyback transformer use.

• External synchronous operation is easily achieved. (This feature, for example, is applicable to

synchronization with a forizontal synchronizing signal of CRT monitor.)

Theory of Current Mode Control

In current mode control, a PWM pulse is generated not by comparing an error voltage with a triangular
wave voltage in the voltage mode, but by changing the current limiter level in accordance with the error
voltage (COMP terminal in this IC, that is,output of the error amplifier output) which is obtained by
constantly monitoring the current of the switching device (power MOSFET) using source resistor RCS.

One of the features of current mode control is that the current limited operates in all cycles of PWM as
described by the above theory.

In voltage mode, only one feedback loop is made by an output voltage. In current mode, on the other hand,
two loops are used. One is an output voltage loop and the other is a loop of the switching device current
itself. The current of the switching device can be controlled switch high speed. In current mode control,
the current in the transformer winding is kept constant, resulting in high stability. An important
consequence is that the line regulation in terms of total characteristics is better than that in voltage mode.

Transformar

AC

input

Current sense
comparator

Error amplifier

DC
output

RS

2R

R

R

S

I

S

V

COMP

Vref

OSC

+

−

−

+

Flip flop

Figure 5 Block Diagram of Current Mode Switching Power Spply

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

16

A. Control in the case of heavy load

B. Control in the case of light load

V

CS

I

S

V

CS

I

S

As the load becomes heavy and the DC output decreases, the current sensing
level is raised as shown in A. above in order to increase the current in the switching
device in each cycle. When the load decreases, inverse control is carried out as
shown in B. above.

Figure 6 Primary Current Control of Transformer in Current Mode (Conceptual Diagram)

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

17

Main Characteristics

Operating Current I

IN

(mA)

Operating Current I

IN

(mA)

Operating Current I

IN

(mA)

Power supply voltage VIN (V)

Ambient temperature Ta (°C)

Operating Current vs. Ambient Temperature

Standby Current/Latch Current vs. Supply Voltage

Exploded diagram of the small current part from the above figure

(HA17384S/H)

Power supply voltage VIN (V)

Standby Current/Latch Current vs. Supply Voltage

Exploded diagram of the small current part from the above figure

(HA17385H)

Power supply voltage VIN (V)

Power supply voltage V

IN

(V)

Ambient temperature Ta (°C)

20

15

10

5

0

010203040

2.0

1.5

1.0

0.5

0

12

11

10

9

8

Ta

=

25°C

Ta = 25°C
fosc = 52kHz

CT = 3300pF
R

T

= 10kΩ

Ta = 25°C
fosc = 52kHz

CT = 3300pF
R

T

= 10kΩ

20

15

10

5

0

010203040

Ta = 25°C

010203040

2.0

1.5

1.0

0.5

0

010203040

400

300

200

100

0

Supply Current vs. Supply Voltage (HA17384S/H) Supply Current vs. Supply Voltage (HA17385H)

Operating Current I

IN

(mA)

Operating Current I

IN

(mA)Standby ⋅ Latch Current (µA)

Standby Current/Latch Current vs. Ambient Temperature

Latch current

(HA17384H)

Latch current

(HA17384H)

Latch current

Stanby current

−20 105806040200 −20 105806040200

VIN = 15V
fosc = 52kHz

CT = 3300pF
R

T

= 10kΩ

Latch current
V

IN

= 15V (HA17384H)

V

IN

= 8.5V (HA17385H)

Latch current

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

18

Ambient temperature Ta (°C)

Ambient temperature Ta (°C)

Ambient temperature Ta (°C)

Supply voltage V

IN

(V)

Output current of Vref terminal (mA)

R

T/CT

terminal voltage V

CT

(V)

UVL Threshold Voltage vs. Ambient Temperature Line Regulation Characteristics of Reference Voltage

Load Regulation Characteristics of Reference Voltage Reference Voltage vs. Ambient Temperature

C

T

Discharge Current vs. RT/CT Terminal Voltage CT Discharge Current vs. Ambient Temperature

UVL voltage (V)

Reference voltage Vref (V)

Reference voltage Vref (V)

Reference voltage Vref (V)

C

T

discharge current I

CT

(mA)

20 5.2

5.1

5.0

4.9

4.8

6.0

5.5

5.0

4.5

4.0
0

20

40 8060 100

Ta = 25°C
VIN = 15V

CT = 3300pF
RT = 10kΩ

9.5

9.0

8.5

8.0

7.5
0

1

23

15

10

5

0

5.2

5.1

5.0

4.9

4.8

Ta = 25°C
VIN = 15V

4

9.5

9.0

8.5

8.0

7.5

C

T

discharge current Isink

CT

(mA)

0

10

20 30

V

TL

V

TH

−20 856040200

−20 10560 8040200

−20 10560 8040200

HA17385H

V

TH

HA17384S/H

V

TL

CT = 3300pF
RT = 10kΩ

CT = 3300pF
RT = 10kΩ

VIN = 15V

VIN=15 V

Ta = 25°C
VIN = 10V or more (HA17384S/H)
VIN = 7.6V or more (HA17385H)

Vref short
protection
operates

Measured when
RT/CT terminal voltage
is externally supplied

Minimum voltage of
triangular wave

Maximum voltage of
triangular wave

Measured when RT/C

T

terminal voltage of 2 V is
externally supplied

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

19

Oscillation frequency fosc (kHz)

Timing resistance R

T

(Ω)

500

200

100

50

20

10

5
500 1k 2k 5k 10k 20k 50k 100k 200k

Ta = 25¡C
V

IN

= 15V

2200pF

4700pF

0.01µF

0.022µF

0.047µF

1000pF

C

T

=470pF

Figure 7 Oscillation Frequency vs. Timing Resistance

Triangular wave

PWM maximum ON pulse

In the case of small C

T

and large R

T

(ex. CT = 3300pF, RT = 10kΩ)

Du max = 95%
fosc = 52kHz

Triangular wave

PWM maximum ON pulse

In the case of large C

T

and small R

T

(ex. CT = 0.033µF, RT = 680Ω)

Du max = 40%
fosc = 52kHz

Case 1.
Setting large maximum duty cycle.

Case 2.
Setting small maximum duty cycle.

Figure 8 Relationship Between Triangular Wave and Maximum ON Duty of PWM Pulse

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

20

Maximum ON duty Du max (%)

Timing Resistance RT (Ω)

Note: In the oscillation system of this IC, a constant discharging current of 8.4mA

flows the timing capacitor during triangular wave fall. Therefore, note that a
small maximum ON duty (large dead band) leads to a large supply current.
Refer to the equations of oscillation frequency and supply current for details.

100

75

50

25

0

500 1k 2k 5k 10k 20k 50k 100k 200k

Ta = 25°C
V

IN

= 15V

Figure 9 PWM Pulse ON Duty vs. Timing Resistance

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

21

Oscillation Frequency fosc (kHz)

Ambient Temperature Ta (°C)

Ambient temperature Ta (°C)

Ambient temperature Ta (°C)

Operating Current I

IN

(mA)

Maximum ON Duty Du max (%)

Output load capacitance C

L

(pF)

Oscillation Frequency vs. Ambient Temperature Operating Current vs. Maximum ON Duty

Rise/Fall Time of Output Pulse vs. Load Capacitance Rise/Fall Time of Output Pulse vs. Ambient Temperature

Rise/Fall Time (ns)

Rise/Fall Time (ns)

Current sensing level V

CS

(V)

V

IN

(UVL1)
Vref

(UVL2)
PWM

OUTPUT

Condition
description

L

L

L

L

H

L

H

H

L

Standby
state

IC is in
the ON
state and
output is
fixed to
LO.

Available
to
output

Current Sensing Level vs. Ambient Temperature

Relationship Between Low Voltage Malfunction

Protection and PWM Output

Operation
state

Standby
state

H

L

65 25

0

25

50 75 100

VIN = 15V

fosc=50kHz

fosc=300kHz

VCS = 0V
VFB = 0V

250

0 1000

2000 3000

Fall Time tf

60

55

50

45

40

20

15

10

5

0

200

150

100

50

0

VIN = 15V
VCS = 0V
VFB = 0V

Ta = 25°C
CT = 3300pF
RT = 10kΩ

4000

250

200

150

100

50

0

1.25

1.00

0.75

0.50

0.25

0

VIN = 15V
CL = 1000pF

CT = 3300pF
RT = 10kΩ

Dumax = 95%

VIN = 15V
VCS = 0V
VFB = 0V

CT = 3300pF
RT = 10kΩ

VIN = 15V
VFB = 0V

Rise time tr

CL = 1000pF

−20 10560 8040200

−20 10560 8040200

−20 10560 8040200

CT = 0.033µF
RT = 680Ω

Dumax = 40%

Ta=25°C
CL = 1000pF

Rise time t

r

Fall Time t

f

Measured when COMP terminal
voltage is externally supplied

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

22

Gain A

VO

(dB)

Error Amplifier Input Signal Frequency f (Hz)

Gain A

VO

100

75

50

25

0

−25

Phase Φ (deg)

0

60

120

180

10 100 1k 10k 100k 1M 10M

Phase Φ

V

IN

= 15V, Ta = 25°C

ΦO = 60° Typ

Phase margin
at f

T

Unit gain frequency
f

T

= 1MHz Typ

Figure 10 Open Loop Gain Characterisrics of Error Amplifier

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

23

Triangular wave

PWM maximum
ON pulse

Dumax is the ratio of
maximum ON time of
PWM to one cycle time.

In the above case,
Dumax = 95%

•

Calculation of operation parameters

1. Maximum ON duty Du max (Refer to the right figure.)
Du max =

1

1 + 1.78 × In 1 +

190Ω

R

T

− 440Ω

(

)

RT = + 440Ω

190Ω

0.56 (1/Du max − 1)

C

T

= 1.78 ×

Du max

fosc × R

T

IDmax =

V

THCS

fosc =

1

C

T

× R

T

× 0.56 + In 1 +

190Ω

(){}

2. Oscillation frequency fosc

From the above two equations, the following two equations are
obtained.

3. Equalization to device R

T

from Du max

e

(e = 2.71828.base of natural logarithm)

4. Equation to device CT from fosc and R

T

5. Operating current I

IN

IIN = IQ + IsinkCT × (1 − Du max) + Ciss × VIN × fosc

providing that I

Q

= 8.4mA Typ (Supply current when oscillation in IC stops.)

Ciss is the input gate capacitance of the power MOSFET which is connected and V

IN

is

the supply voltage of the IC.

Note that the actual value may differ from the calculated one because of the internal
delay in operation and input characteristics of the POWER MOS FET. Check the
value when mounting.
Additionally a small Dumax leads to a large supply current, even if the frequency is
not changed, and start up may become difficult. In such a case, the following
measure is recommended.

Example 1: Calculation when R

T

= 10kΩ and CT = 3300pF

fosc = 52kHz, Du max = 95%, I

IN

= 9.7mA
Example 2: Calculation for 50% of Du max and 200 kHz of fosc
R

T

= 693Ω, CT = 6360pF, IIN = 12.5mA

(1) For an AC/DC converter, a small bleeder resistance is required.
(2) The large capacitance between Vref and GND is required.
(3) Use a large Dumax with a triangular wave and raise the current limit of the

switching device to around the maximum value (1.0V Typ).
The current limit is expressed as

R

T

− 440Ω

However, Ciss = 1000pF, V

IN

= 18V

R

CS

− 1

Figure 11 Calculation of Operation Parameters

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

24

Application Circuit Example (1)

Notes:

P

Snubber circuit
example

51

470p

1kV

FRD
DFG1C8

1. : PRIMARY GND, : SECONDARY GND.

2. Check the wiring direction of the transformer coil.

3. Insert a snubber circuit if necessary.

4. OVP function is not included in HA17384SPS/SRP.

Commercial
AC 100V

Rectifier bridge diode

Line filter

Transformer specification
example
EI-22 type core
(H7C18 × 06Z)
Gap length
lg = 0.3mm

Transformer coil example
P: 0.5¿80T/570µH
S: 0.5¿16T Bifiler/22µH
B: 0.2¿44T/170µH

S

(Opetation Theory)
Because this circuit is a flyback type, the voltages in the
primary (P), secondary (s) coils of the transformer and
backup (B) coil are proportional to each other. Using this,
the output voltage of the backup coil (V

IN

of IC) is controlled
at constant 16.4V. (The voltage of the point divided by
resistors of 20kΩ and 3.6kΩ is 2.5V).

20k

3.6k

100µ
200V

1000µ
10V

R

T

10k

220k
1/4W

10µ

50V

V

IN

16.4V

0.1µ

51

1k

1k

−

+

B

P

S

HRP32

DC 5V, 3A
OUTPUT

Vref

V

IN

OUT

GND

COMP

FB

HA17384H,
HA17385H

2SK1567

SBD
HRP24

CS

R

T/CT

+

−

+

−

+

−

+

−

1
2W

100p

150k

470p

C

T

3300p

141V

10k

2SA1029

HA17431

10k

47k

Figure 12 Primary Voltage Sensing Flyback Converter

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

25

Application Circuit Example (2)

Photocoupler
(for output control)

Commercial
AC 100V

Rectifier bridge diode

When the error amplifier is used

Line filter

Transformer specification
example
EI-22 type core
(H7C18 × 06Z)
Gap length
lg = 0.3mm

Transformer coil example
P: 0.5¿80T/570µH
S: 0.5¿16T Bifiler/22µH
B: 0.2¿44T/170µH

(Operation Theory)
On the secondary side (S) of the flyback converter,
error amplification is carried out by a shunt
regulator and photocoupler.
The voltage of the backup coil (B) is not monitored,
which differs from the application example (1).

In addition, OVP operates on the secondary side
(S) using a photocoupler.

Refer to the application example (1) for the other
notes.

When the error
amplifier is not used

Bleeder resistor
(adjuster according
to the rating of the
Photocoupler)

100µ
200V

1000µ
10V

R

T

10k

220k
1/4W

10µ

50V

V

IN

16.4V

141V

0.1µ

51

1k

4.7k

−

+

B

P

S

HRP32

DC
5V, 3A
OUTPUT

Vref

V

IN

OUT

GND

COMP

FB

HA17384H,
HA17385H

HA17431

2SK1567

SBD
HRP24

CS

R

T/CT

RT/C

T

+

−

+

−

+

−

+

−

1.8k

B

4.7k

1
2W

100p

150k

470p

C

T

3300p

330

3.3µ

3.3k

+

−

Vref

V

IN

OUT

GND

FB
CS

0.8mA

COMP

OVP input

1k

47k HA17431

2SA1029

10k

10k

Figure 13 Secondary Voltage Sensing Flyback Converter

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

26

Application Examples for Fuller Exploitation of Power Supply Functions

A number of application examples are briefly described below.

1. Soft start
A soft start is a start method in which the PWM pulse width is gradually increased when the power

supply is activated. This prevents the stress on the transformer and switch element caused by a rapid
increase in the PWM pulse width, and also prevents overshoot when the secondary-side output voltage
rises. The circuit diagram is shown in figure 14.

−

+

EA

I

O

800µA typ

Vref
5V

(3V)

(4.4V)

(3.7V)

(5V)

7V

IN

D

IN

V

REF

R

CU

C

ST

D2

D1

2

2.5V

IC internal circuit
(around error amp.)

External circuit
(only partially shown)

FB

R

1V

To power supply
detection
comparator

(1V)

COMP

8

1

2R

Figure 14 Circuit Diagram for Soft Start

Operation: In this circuit, error amp output source current IO (800 µA typ.) gradually raises the switch
element current detection level, using a voltage slope that charges soft start capacitance CST. When the
voltage at each node is at the value shown in parentheses in the figure, the soft start ends. The soft start
time is thus given by the following formula:

TST = (3.7 V/800 µA) × CST ≈ 4.62 CST (ms)

(C

ST

unit: µF)

External parts other than CST operate as follows:

• Diode D1 : Current detection level shift and current reverse-flow prevention.

• Diode D2 : Together with diode DIN in the IC, CST charge drawing when power supply falls.

• Resistance RCU: For CST charge-up at end of soft start. (Use a high resistance of the order of several

hundred kΩ.)

Note: During a soft start, since PWM pulses are not output for a while after the IC starts operating, there

is a lack of energy during this time, and intermittent mode may be entered. In this case, the
capacitance between Vref and GND should be increased to around 4.7 µF to 10 µF.

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

27

2. OVP latch output overvoltage protection (the HA17384H and HA17385H only)
The OVP latch is incorporated in the error amp input pin (FB). If the FB pin is pulled up to 7.0 V typ.

just once when the power supply enters any kind of error state, IC operation can be halted and held as it
is (latched). To reset the latch, drop the IC’s supply voltage to 7.0 V typ. or below momentarily.

An OVP latch application example is shown in figure 15.

−

+

EA

V

IN

R247k

2

2.5V

Inside IC

OVP comparator

FB

Error amplifier

−

+

OVP

7.0V

COMP

1

R110k

HA17431
(Vref ≈ 2.5V)

1k

2SA1029

R

3

10k

External circuit
(only partially shown)

Figure 15 Example of OVP Latch Application Circuit

This circuit protects the system by causing latch operation in the event of an overload or load short. In
the steady state, the error amp input/output pins operate at 2.5 V typ., but if the load becomes heavy the
FB pin level drops and the COMP pin level rises. As shown in the figure, this is detected by the
HA17431 shunt regulator, and the FB pin level is pulled up, operating the OVP latch.

The operation parameters are as follows:

COMP pin voltage detection level: Vth = (R1 + R2) / R2 × 2.5 V

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

28

Notice for Use

1. OVP Latch Block

• Case
When DC power is applied directly as the power supply of the HA17384H, HA17385H, without using

the transformer backup coil. Also, when high-frequency noise is superimposed on the VIN pin.

• Problem
The IC may not be turn on in the case of a circuit in which VIN rises quickly (10 V/100 µs or faster),

such as that shown in figure 16. Also, the OVP latch may operate even though the FB pin is normally at
V

OVP

or below after the IC is activated.

• Reason
Because of the IC circuit configuration, the timer latch block operates first.

• Remedy (counter measure)
Take remedial action such as configuring a time constant circuit (RB, CB) as shown in figure 17, to keep

the VIN rise speed below 10 V/100 µs. Also, if there is marked high-frequency noise on the VIN pin, a
noise cancellation capacitor (CN) with the best possible high-frequency characteristics (such as a
ceramic capacitor) should be inserted between the VIN pin and GND, and close to the VIN pin.

When configuring an IC power supply with an activation resistance and backup winding, such as an
AC/DC converter, the rise of VIN will normally be around 1 V/100 µs, and there is no risk of this problem
occurring, but careful attention must be paid to high-frequency noise.

Also, this phenomenon is not occuring to the HA17384S, because OVP function is not built-in.

OutputInput

V

IN

V

IN

GND

Feedback

HA17384

Series

Figure 16 Example of Circuit with Fast VIN Rise Time

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

29

OutputInput

Time constant

circuit

Feedback

HA17384

Series

V

IN

V

IN

18V

R

B

51Ω

C

N

C

B

1µF

GND

+

Figure 17 Sample Remedial Circuit

2. Externally Synchronized Operation

• Case
When, with a power supply using the HA17384S/H or HA17385H, externally synchronized operation is

performed by applying an external syncronous signal to the RT/CT pin (pin 4).

• Problem
Synchronized operation may not be possible if the amplitude of the external syncronous signal is too

large.

• Reason
The RT/CT pin falls to a potential lower than the ground.

• Remedy (counter measure)
In this case, clamping is necessary using a diode with as small a VF value as possible, such as a schottky

barrier diode, as shown in figure 18.

Vref

0.01µF

R

T

C

T

47

HA17384

Series

External

synchronous

signal

Figure 18 Sample Remedial Circuit

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

30

Package Dimensions

Hitachi Code
JEDEC
EIAJ
Mass

(reference value)

DP-8
Conforms
Conforms

0.54 g

Unit: mm

1

4

58

9.6

10.6 Max

0.89

1.3

6.3

7.4 Max

2.54 Min

5.06 Max

2.54 ± 0.25

0.48 ± 0.10

7.62

0.25

+ 0.10
– 0.05

0° – 15°

0.1 Min

1.27 Max

Hitachi Code
JEDEC
EIAJ
Mass

(reference value)

FP-8DC
Conforms
—

0.085 g

Unit: mm

*Dimension including the plating thickness

Base material dimension

1.75 Max

4.90

0.25

0.15

0° – 8°

M

8

5

1

4

1.27

3.95

0.40 ± 0.06

*0.42 ± 0.08

5.3 Max

0.75 Max

0.14

+ 0.11

– 0.04

0.20 ± 0.03

*0.22 ± 0.03

0.60

+ 0.67
– 0.20

6.10

+ 0.10
– 0.30

1.08

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

31

Cautions

1. Hitachi neither warrants nor grants licenses of any rights of Hitachi’s or any third party’s patent,
copyright, trademark, or other intellectual property rights for information contained in this document.
Hitachi bears no responsibility for problems that may arise with third party’s rights, including
intellectual property rights, in connection with use of the information contained in this document.

2. Products and product specifications may be subject to change without notice. Confirm that you have
received the latest product standards or specifications before final design, purchase or use.

3. Hitachi makes every attempt to ensure that its products are of high quality and reliability. However,
contact Hitachi’s sales office before using the product in an application that demands especially high
quality and reliability or where its failure or malfunction may directly threaten human life or cause risk
of bodily injury, such as aerospace, aeronautics, nuclear power, combustion control, transportation,
traffic, safety equipment or medical equipment for life support.

4. Design your application so that the product is used within the ranges guaranteed by Hitachi particularly
for maximum rating, operating supply voltage range, heat radiation characteristics, installation
conditions and other characteristics. Hitachi bears no responsibility for failure or damage when used
beyond the guaranteed ranges. Even within the guaranteed ranges, consider normally foreseeable
failure rates or failure modes in semiconductor devices and employ systemic measures such as fail­safes, so that the equipment incorporating Hitachi product does not cause bodily injury, fire or other
consequential damage due to operation of the Hitachi product.

5. This product is not designed to be radiation resistant.

6. No one is permitted to reproduce or duplicate, in any form, the whole or part of this document without
written approval from Hitachi.

7. Contact Hitachi’s sales office for any questions regarding this document or Hitachi semiconductor
products.

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Nippon Bldg., 2-6-2, Ohte-machi, Chiyoda-ku, Tokyo 100-0004, Japan
Tel: Tokyo [phone] Fax: [phone]

Copyright ' Hitachi, Ltd., 1998. All rights reserved. Printed in Japan.

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