Datasheet HA17384HRP, HA17385HRP, HA17384SRP Datasheet (HIT)

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

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) *

• TSD function (thermal shut-down protection) *

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

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

Note: 1. H series only.

2. S series only.

1

1

1

1

2

2

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

Product Line-up

UVL Power Supply

Package Additional Function

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

TSD
(Thermal shut­down protection)

OVP
(Over voltage
protection) V

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

Pin Arrangement

Threshold Voltage

(V) Typ V

TH UVL

TL UVL

(V) Typ

COMP

FB

CS

R

T/CT

1

2

3

4

8

Vref

7

V

IN

6

OUT

GND

5

(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
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.

/C

T

T

Timing resistance, timing capacitance connect pin

3

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

Block Diagram

COMP

FB

(OVP input)

CS

0.8mA
UVL1

1

−

EA

+

6.5V

1

Vref

2

(2.5V)

−

OVP

+

2

7.0V

1V

*1

2V

F

2R

R

−

CS

3

+

H

L

OVP
latch

S

TSD

sense

160°C

CS

latch

R
S

Q

PWM LOGIC

Vref

VL

VH

Q

5V band
gap
reference
regulator

UVL2

Vref > 4.7VR

OR

NOR

OUT

Totem pole
output circuit

34V

8

Vref

7

V

IN

6

OUT

RT/CT

Oscillator

4

8.4 mA

+

−

1.2V

2.8 V

Latch set

pulse

5 GND

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

4

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

Absolute Maximum Ratings

Item Symbol Rating Unit Note

Supply voltage V
DC output current I
Peak output current I
Error amplifier input voltage V
COMP terminal input voltage V
Error output sink current I
Power dissipation P

IN

O

O PEAK

FB

COMP

OEA

T

Operating temperature Topr –20 to +105 °C
Junction temperature Tj 125 °C3

Storage temperature Tstg –55 to +125 °C3

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.

30 V

±0.1 A
±1.0 A

–0.3 to V

IN

V
–0.3 to +7.5 V
10 mA
680 mW 1, 2

150 °C4

–55 to +150 °C4

800

680mW

600

(mW)

T

374mW

400

166mW

200

Power Dissipation P

43°C 68°C 150°C

HA17384SPS

HA17384HPS, HA17385HPS

105°C 125°C

0

−20 0 20 40 60 80 100 120 140 160
Ambient Temperature Ta (°C)

5

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

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%.

HA17384SRP
: −11.1 mW/°C (wiring density is 30%)

800

600

(mW)

T

680 mW

500 mW

: −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%)

374 mW

400

222 mW

200

Power Dissipation P

166 mW

0

−20 0 20 40 60 80 100 120 140 160

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

4. Applies to the HA17384SPS/SRP.

43°C63°C

Ambient Temperature Ta (°C)

68°C 105°C 125°C

150°C89°C

6

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

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
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

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

Maximum oscillating
frequency

Supply voltage dependency of
oscillating frequency

Temperature dependency of
oscillating frequency

Discharge current of C

T

Low level threshold voltage V
High level threshold voltage V
Triangular wave amplitude ∆V

Notes: 1. Reference value for design.

fosc Max 500 — — kHz

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

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

Isink

TLCT

THCT

CT

7.5 8.4 9.3 mA VCT = 2.0 V

CT

— 1.2 — V 1
— 2.8 — V 1
— 1.6 — V ∆VCT = V

IN

= 3300 pF,

T

R

= 10 kΩ

T

≤ 25 V

THCT

– V

TLCT

1

1

7

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

Electrical Characteristics (cont)

Error Amplifire Part / OVP Part

Item Symbol Min Typ Max Unit Test Condition Note

Non-inverting input voltage V
Input bias current I
Open loop voltage gain A

FB

IB

VOL

2.42 2.50 2.58 V V
— –0.2 –2.0 µAVFB = 5.0 V

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

PSRR 60 70 — dB 12 V ≤ VIN ≤ 25 V

rejection ratio
Output sink current I
Output source current I
High level output voltage V

Low level output voltage V

OVP latch threshold

Osink EA

Osource EA

OH EA

OL EA

V

OVP

3.0 9.0 — mA VFB = 2.7 V, V

–0.5 –0.8 — mA VFB = 2.3 V, V

5.5 6.5 7.5 V VFB = 2.3 V,

— 0.7 1.1 V VFB = 2.7 V,

6.0 7.0 8.0 V Increase FB terminal

voltage
OVP (FB) terminal input

I

FB(OVP)

—3050µAVFB = 8.0 V 1
current

OVP latch reset VIN voltage V

IN(OVP RES)

6.0 7.0 8.0 V Decreasing VIN after OVP

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

= 2.5 V

COMP

R

= 15 kΩ(GND)

L

R

= 15 kΩ(Vref)

L

voltage

latched

COMP

COMP

= 1.1 V
= 5.0 V

1

1

8

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

Electrical Characteristics (cont)

Current Sensing Part

Item Symbol Min Typ Max Unit Test Condition Note

Voltage gain A
Maximum sensing voltage Vth
Power supply voltage

VCS

CS

PSRR — 70 — dB 12 V ≤ VIN ≤ 25 V 2

rejection ratio
Input bias current I
Current sensing

BCS

tpd 50 100 150 ns Time from when V

response time

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.

2.85 3.00 3.15 V/V VFB = 0 V 1

0.9 1.0 1.1 V

— –2 –10 µAVCS = 2 V

becomes 2 V to when

CS

output becomes “L” (2 V)

Vth

V

CS

3

V

OUT

(PWM)

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
Output low voltage 2 V
Output high voltage 1 V
Output high voltage 2 V
Output low voltage at

V

OL1

OL2

OH1

OH2

OL STB

standby mode
Rise time t
Fall time t

r

f

Maximum ON duty Du max 94 96 100 %
Minimum ON duty Du min — — 0 %

Notes: 1. Pulse application test

— 0.7 1.5 V losink = 20 mA
— 1.5 2.2 V losink = 200 mA 1

13.0 13.5 — V losource = –20 mA

12.0 13.3 — V losource = –200 mA 1
— 0.8 1.1 V VIN = 5 V,

losink = 1 mA
— 80 150 ns CL = 1000 pF
— 70 130 ns CL = 1000 pF

9

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

Electrical Characteristics (cont)

UVL Part

Item Symbol Min Typ Max Unit Test Condition Note

Threshold voltage for V

TH UVL

high VIN level 7.6 8.4 9.2 V when VIN is rising 2
Threshold voltage for V

TL UVL

low VIN level 6.8 7.6 8.4 V voltage after turn-ON 2
V

UVL hysteresis voltage V

IN

Vref UVL threshold voltage V

HYS UVL

T Vref

Notes: 1. For the HA17384S/H.

2. For the HA17385H.

Total Characteristics

Item Symbol Min Typ Max Unit Test Condition Note

Operating current I
Standby current I
Current of latch I
Power supply zener

IN

STBY

LATCH

V

INZ

voltage
Overheat protection

Tj

TSD

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

2. V

= 8.5 V in case of the HA17384H.

IN

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

4. Reference value for design.

7.0 10.0 13.0 mA CL = 1000 pF, VFB = VCS = 0 V
120 170 230 µA Current at start up
200 270 340 µAVFB = 0 V after VFB = V
31 34 37 V IIN + 2.5 mA

— 160 — °C 3, 4

14.5 16.0 17.5 V Turn-ON voltage 1

9.0 10.0 11.0 V Minimum operating 1

5.0 6.0 7.0 V V

HYS UVL

= V

TH UVL

– V

TL UVL

0.6 0.8 1.0 V 2

4.3 4.7 Vref V Voltage is forced toVref
terminal

OVP

1

1, 2

10

Timing Chart

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

Waveform timing (Outline)Signal Name

Input voltage
V

Pin 7

IN

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

Pin 4

T/CT

Start up signal
Internal signal which
cannot be externally
monitored.

Power ON IC turn ON

16 V

(8.4 V)

2 V

0V

( ) shows the case
using HA17385H

0V

0V

4.7 V

0V

0V

IC operates and
PWM output stops.

0V

Stationary operation

This voltage is determined
by the transformer

5 V

2.8 V

1.2 V

Start up latch
release

4.7 V

OVP input

OVP latched
condition

Power OFF

10 V

(7.6 V)

Reset of
OVP latch

7.0 V
2 V

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

Error amplifier input signal
V

Pin 2

FB

Error amplifier output signal
V

Pin 1

COMP

1

*

I

D

OVP latch signal
Internal signal which
cannot be externally
monitored.

PWM output voltage
V

Pin 6

OUT

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

Note: 1.

I

D

by power MOSFET current detection source resistance R
V

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

COMP

performed so that a voltage 1/3 that of V

0V

0V

0V

0V

0V

7.0 V typ
(OVP input)

V

COMP

I

D

V

IN

.

S

is the current limiter level.

COMP

11

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

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
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.

T

12

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

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

R

B

220k
1/4W

HRP32

C

B

+

−

51

P

B

0.1µ

SBD

ex. HRP24

+

S

−

1000µ
10V

Floating
ground

Power MOSFET
ex. 2SK1567

R

CS

1
2W

+

DC
output

−

Power switch Line filter

OVP input

(Ex: from photocoupler)

R

10k

C

3300p

−

Rectifier
bridge diode

20k

3.6k

150k

T

T

V

100p

CS

330p

V

COMP

FB
CS

RT/C

T

HA17384H,
HA17385H

+

−

100µ

+

200V

IN

10µ
50V

Vref

V

IN

OUT
GND

1k

Figure 2 Mounting Circut Diagram for Operation Expression

13

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

V

COMP

COMP terminal

F

(Error output)

CS

latch

Latch setting pulse
(Implemented in triagular
wave oscillator)

1

×

3

PWM pulse

V

CS terminal

1 V

−

CS

V
Current sensing
level

+

Latch setting
pulse

V
Error voltage

CS

2 R

R

CS

COMP

2V

R
S Q

Figure 3 Operation Diagram of Current Sensing Part

1) At maximum rated load, the setting should be made to give

Point:

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

(V)

CS

Heavy load

0.6

0.4
Light load

0.2

Current Sense Comparator

Threshold Voltage V

0.0

1.4V

C

012345678

Error Amplifier Output Voltage Vcomp (V)

Figure 4 Current Sense Characteristics

B

A : Stationary operation / PWM

A

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

4.4V 7.5V

14

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

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.

AC

input

OSC

S

Flip flop

R

Current sense
comparator

RS

+

−

2R

R

Transformar

I

S

V

Error amplifier

COMP

DC
output

−

+

Vref

Figure 5 Block Diagram of Current Mode Switching Power Spply

15

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

A. Control in the case of heavy load

V

CS

I

S

B. Control in the case of light load

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)

16

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

Main Characteristics

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

20

(mA)

15

IN

Ta = 25°C
fosc = 52kHz

CT = 3300pF

= 10kΩ

R

T

20

(mA)

15

IN

Ta = 25°C
fosc = 52kHz

CT = 3300pF

= 10kΩ

R

T

10

Latch current

5

(HA17384H)

Operating Current I

0

010203040

Power supply voltage VIN (V)

Standby Current/Latch Current vs. Supply Voltage

Exploded diagram of the small current part from the above figure

2.0

(mA)

1.5

IN

Ta = 25°C

1.0

(HA17384S/H)

Latch current

(HA17384H)

0.5

Operating Current I

0

010203040

Power supply voltage VIN (V)

10

5

Latch current

Operating Current I

0

010203040

Power supply voltage V

Standby Current/Latch Current vs. Supply Voltage

Exploded diagram of the small current part from the above figure

(mA)Standby ⋅ Latch Current (µA)

2.0

1.5

IN

Ta

=

(HA17385H)

25°C

(V)

IN

1.0

Latch current

0.5

Operating Current I

0

010203040

Power supply voltage VIN (V)

Operating Current vs. Ambient Temperature

12

(mA)

11

IN

VIN = 15V
fosc = 52kHz

CT = 3300pF

= 10kΩ

R

T

10

9

Standby Current/Latch Current vs. Ambient Temperature

400

300

200

100

Operating Current I

8

−20 105806040200 −20 105806040200
Ambient temperature Ta (°C)

Latch current
V

IN

V

IN

Stanby current

0

Ambient temperature Ta (°C)

= 15V (HA17384H)
= 8.5V (HA17385H)

17

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

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

20 5.2

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

5.1

5.0

4.9

15

10

UVL voltage (V)

5

HA17384S/H

V

TH

V

TL

HA17385H

V

TH

V

TL

Reference voltage Vref (V)

0

−20 856040200
Ambient temperature Ta (°C)

4.8
0

10

Supply voltage V

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

6.0

Ta = 25°C
VIN = 15V

CT = 3300pF
RT = 10kΩ

5.2

VIN = 15V

CT = 3300pF
RT = 10kΩ

20 30

(V)

IN

CT = 3300pF
RT = 10kΩ

5.5

5.0

Vref short

4.5

protection
operates

Reference voltage Vref (V)

4.0
20

0

40 8060 100

Output current of Vref terminal (mA)

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

C

T

9.5

Ta = 25°C

(mA)

CT

9.0

8.5

VIN = 15V

Minimum voltage of
triangular wave

8.0

discharge current I

T

C

Measured when
RT/CT terminal voltage
is externally supplied

Maximum voltage of
triangular wave

7.5
0

1

R

terminal voltage V

T/CT

23

(V)

CT

4

5.1

5.0

4.9

Reference voltage Vref (V)

4.8

−20 10560 8040200
Ambient temperature Ta (°C)

9.5

(mA)

CT

9.0

VIN=15 V

Measured when RT/C
terminal voltage of 2 V is
externally supplied

8.5

8.0

discharge current Isink

T

C

7.5

−20 10560 8040200

Ambient temperature Ta (°C)

T

18

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

500

200

100

50

20

Oscillation frequency fosc (kHz)

10

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

Figure 7 Oscillation Frequency vs. Timing Resistance

Case 1.
Setting large maximum duty cycle.

1000pF

2200pF

4700pF

0.01µF

0.022µF

0.047µF

Timing resistance R

Triangular wave

Ta = 25¡C
V

= 15V

IN

C

T

=470pF

(Ω)

T

PWM maximum ON pulse

Du max = 95%
fosc = 52kHz

In the case of small C

and large R

T

T

(ex. CT = 3300pF, RT = 10kΩ)

Case 2.
Setting small maximum duty cycle.

Triangular wave

PWM maximum ON pulse

Du max = 40%
fosc = 52kHz

In the case of large C

and small R

T

T

(ex. CT = 0.033µF, RT = 680Ω)

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

19

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

100

75

50

25

Maximum ON duty Du max (%)

0

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

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.

Ta = 25°C
V

= 15V

IN

Figure 9 PWM Pulse ON Duty vs. Timing Resistance

20

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

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

65 25

VIN = 15V
CL = 1000pF

60

55

50

Dumax = 95%

CT = 3300pF
RT = 10kΩ

20

(mA)

IN

15

10

VIN = 15V

Ta=25°C
CL = 1000pF

fosc=300kHz

fosc=50kHz

VCS = 0V
VFB = 0V

45

Oscillation Frequency fosc (kHz)

40

Dumax = 40%

−20 10560 8040200
Ambient Temperature Ta (°C)

CT = 0.033µF
RT = 680Ω

5

Operating Current I

0

0

25

Maximum ON Duty Du max (%)

50 75 100

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

250

Ta = 25°C
CT = 3300pF
RT = 10kΩ

200

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

150

100

Rise/Fall Time (ns)

50

0

0 1000

Output load capacitance C

Rise time tr

Fall Time tf

2000 3000

L

4000

(pF)

Current Sensing Level vs. Ambient Temperature

1.25

(V)

1.00

CS

VIN = 15V
VFB = 0V

Measured when COMP terminal
voltage is externally supplied

0.75

0.50

0.25

Current sensing level V

0

250

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

200

150

100

Rise/Fall Time (ns)

50

Rise time t

Fall Time t

CL = 1000pF

CT = 3300pF
RT = 10kΩ

r

f

0

−20 10560 8040200
Ambient temperature Ta (°C)

Relationship Between Low Voltage Malfunction

Protection and PWM Output

V

IN

(UVL1)
Vref

(UVL2)
PWM

OUTPUT

Condition
description

L

L

L

Standby
state

H

L

L

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

H

H

Available
to
output

Operation
state

L

H

L

Standby
state

−20 10560 8040200
Ambient temperature Ta (°C)

21

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

100

V

= 15V, Ta = 25°C

IN

75

50

(dB)

VO

25

Gain A

VO

Unit gain frequency
f

= 1MHz Typ

T

0

0

Gain A

−25

Phase Φ

Phase margin
at f

T

ΦO = 60° Typ

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

Error Amplifier Input Signal Frequency f (Hz)

Figure 10 Open Loop Gain Characterisrics of Error Amplifier

60

120

180

Phase Φ (deg)

22

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

Calculation of operation parameters

•

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

1 + 1.78 × In 1 +

2. Oscillation frequency fosc
fosc =

C

× R

× 0.56 + In 1 +

T

T

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

3. Equalization to device R
RT = + 440Ω

0.56 (1/Du max − 1)

e

190Ω

4. Equation to device CT from fosc and R

= 1.78 ×

C

T

Du max

fosc × R

5. Operating current I

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

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

the supply voltage of the IC.
Example 1: Calculation when R
fosc = 52kHz, Du max = 95%, I
Example 2: Calculation for 50% of Du max and 200 kHz of fosc
R

= 693Ω, CT = 6360pF, IIN = 12.5mA

T

However, Ciss = 1000pF, V

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.
(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

1

190Ω

(

R

− 440Ω

T

)

1

190Ω

(){}

from Du max

T

− 440Ω

R

T

− 1

(e = 2.71828.base of natural logarithm)

T

T

IN

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

Q

= 10kΩ and CT = 3300pF

T

= 9.7mA

IN

= 18V

IN

V

IDmax =

THCS

R

CS

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%

is

IN

Figure 11 Calculation of Operation Parameters

23

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

Application Circuit Example (1)

Rectifier bridge diode

−

10k

Commercial
AC 100V

2SA1029

10k

47k

HA17431

R

10k

+

Line filter

20k

3.6k

150k

T

C

T

3300p

100p

470p

HA17384H,
HA17385H

COMP

FB

CS

R

T/CT

1k

16.4V

141V

+

100µ
200V

10µ

50V

V

IN

220k
1/4W

HRP32

+

−

0.1µ

51

SBD
HRP24

P

B

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

2SK1567

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

1
2W

1000µ
10V

+

S

−

−

V

IN

Vref

OUT

GND

1k

+

DC 5V, 3A
OUTPUT

−

Notes:

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.

Snubber circuit
example

470p

1kV

FRD
DFG1C8

(Opetation Theory)
Because this circuit is a flyback type, the voltages in the

51

P

primary (P), secondary (s) coils of the transformer and
backup (B) coil are proportional to each other. Using this,

S

the output voltage of the backup coil (V
at constant 16.4V. (The voltage of the point divided by

IN

resistors of 20kΩ and 3.6kΩ is 2.5V).

Figure 12 Primary Voltage Sensing Flyback Converter

of IC) is controlled

24

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

Application Circuit Example (2)

When the error amplifier is used

Commercial
AC 100V

2SA1029

R

T

10k

C

T

3300p

10k

150k

Line filter

10k

47k HA17431

100p

470p

−

HA17384H,
HA17385H

COMP

FB

CS

R

T/CT

1k

Rectifier bridge diode

+

16.4V

1k

V

IN

Vref

V

OUT

GND

141V

+

100µ

−

200V

10µ
50V

IN

220k
1/4W

HRP32

+

B

−

0.1µ

2SK1567

51

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

Transformer coil example

P: 0.5¿80T/570µH
SBD
HRP24

P

S

4.7k

1
2W

S: 0.5¿16T Bifiler/22µH

B: 0.2¿44T/170µH

+

−

1.8k

1000µ
10V

4.7k

330

3.3µ
+

−

B

HA17431

Photocoupler
(for output control)

3.3k

+

DC
5V, 3A
OUTPUT

−

When the error
amplifier is not used

OVP input

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

(Operation Theory)

Vref

COMP

FB
CS

RT/C

0.8mA

T

On the secondary side (S) of the flyback converter,
error amplification is carried out by a shunt
regulator and photocoupler.

V

IN

The voltage of the backup coil (B) is not monitored,

OUT

which differs from the application example (1).

GND

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

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

Figure 13 Secondary Voltage Sensing Flyback Converter

25

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

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.

7V

IN

2

FB

2.5V

IC internal circuit
(around error amp.)

I

O

800µA typ

−

EA

+

2R

(4.4V)

(3V)

(1V)

R

D

IN

Vref
5V

To power supply
detection

1V

comparator

V

REF

8

COMP

1

External circuit
(only partially shown)

(5V)

R

CU

D1

C

ST

D2

(3.7V)

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)

unit: µF)

(C

ST

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.

26

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

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.

V

IN

R
10k

3

FB

2SA1029

2

2.5V

7.0V

−

EA

+

Error amplifier

−

OVP

+

OVP comparator

Inside IC

1

COMP

R110k

R247k

1k

HA17431
(Vref ≈ 2.5V)

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

27

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

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

or below after the IC is activated.

OVP

• 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

HA17384

Series

GND

IN

Feedback

V

IN

Figure 16 Example of Circuit with Fast VIN Rise Time

28

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

OutputInput

Time constant

circuit

V

IN

18V

+

C

B

1µF

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.

HA17384

Series

GND

R
51Ω

V

B

C

IN

N

Feedback

HA17384

Series

Vref

R

C

47

T

T

0.01µF

External

synchronous

signal

Figure 18 Sample Remedial Circuit

29

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

Package Dimensions

9.6

10.6 Max
58

6.3

7.4 Max

1

0.89

4

1.3

Unit: mm

2.54 ± 0.25

0.75 Max

1.27 Max

4.90

5.3 Max

8

1

1.27

*0.42 ± 0.08

0.40 ± 0.06

0.1 Min

0.48 ± 0.10

5

3.95

4

5.06 Max

2.54 Min

1.75 Max

+ 0.11

– 0.04

0.14

0.15

7.62

0° – 15°

Hitachi Code
JEDEC
EIAJ

(reference value)

Mass

6.10

0.20 ± 0.03

*0.22 ± 0.03

0.60

+ 0.10
– 0.30

+ 0.67
– 0.20

0.25

1.08

+ 0.10
– 0.05

0° – 8°

DP-8
Conforms
Conforms

0.54 g

Unit: mm

*Dimension including the plating thickness

Base material dimension

30

0.25

M

Hitachi Code
JEDEC
EIAJ
Mass

(reference value)

FP-8DC
Conforms
—

0.085 g

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP

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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Tel: <886> (2) 2718-3666
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Copyright ' Hitachi, Ltd., 1998. All rights reserved. Printed in Japan.

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7/F., North Tower, World Finance Centre,
Harbour City, Canton Road, Tsim Sha Tsui,
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Tel: <852> (2) 735 9218
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31