ROHM BD9763FVM Technical data

Large Current External FET Controller Type Switching Regulators

Single-output Step-up,High-efficiency Switching Regulator (Controller Type)

BD9763FVM

●Description

BD9763FVM is a 1-channel high efficiency step-up switching regulator. It is possible to choose small application space due to its high-speed operation (Max switching frequency 1.2MHz)

●Features

1) Build-in under voltage lock out circuit.

2) High accuracy reference voltage (2.5V±1.0%)

3) Establish maximum duty cycle internally.

4) CTL/SS terminal for both stand-by and soft-start function. (Soft-start time can be set by external capacitor)

5) MSOP8 thin and small package.

●Applications

Single-lens reflex cameras, digital video cameras, liquid crystal modules, DVD drive.

●Absolute Maximum Ratings(Ta=25℃)

Parameter Symbol Limit Unit

Supply voltage Vcc 10 V Storage temperature range Tstg -55 to +150 ℃

Power dissipation Pd 587 * mW

Junction temperature Tjmax +150 ℃

* IC mounted on a PCB board (70mm x 70mm x 1.6mm, glass epoxy). Reduced by 4.7mW for each increase in Ta of 1℃ over 25℃.

●Recommended Operating Conditions

Parameter Symbol

Supply voltage Vcc 4 7 9 V

Oscillating frequency fosc 100 - 1200 kHz Operating temperature range Topr -40 - +85 ℃

Min Typ Max

Limit

No.09028EAT07

Unit

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●Electrical characteristics (Unless otherwise specified, Ta=25℃, Vcc=7.0V)

Parameter Symbol

Min Typ Max

Limits

Unit Condition

【Oscillator】

Oscillating frequency fosc 522 600 678 kHz RRT=24kΩ

Frequency tolerance FDV -5 0 5 % Vcc=4 to 9V Swing voltage Vpptr － 0.5 － V

【Stand-by, Soft start】

CTL/SS pin source current ISS -1.90 -1.00 -0.55 µA V

CTL/SS

=1.5V

CTL/SS pin clamp voltage VSS 2.2 2.4 2.6 V

CTL threshold voltage VCTLTH 1.2 1.3 1.4 V

【PWM comparator】

0% threshold voltage D0 1.5 1.6 1.7 V

Maximum duty cycle DMAX 80 90 99.5 %

【Error amplifier】

Threshold voltage VIN 0.98 1.00 1.02 V Band width BW － 3.0 － MHz AV=0dB

Voltage gain Av － 70 － dB Input bias current IIB -150 -70 － nA

Maximum output voltage VCH 2.3 2.4 2.6 V Minimum output current VCL － 0.03 0.20 V

Output source current IOI -3.1 -1.6 -1.0 mA VFB=1.0V

Output sink current IOO 12 50 125 mA VFB=1.0V

【Reference voltage】

Output voltage VREF 2.475 2.500 2.525 V I Load regulation △VREFlo - - 10 mV I

=0mA

VREF

=0 to -1mA

VREF

Output short current IVREF -45 -16 -1 mA

【Whole device】

Stand-by current ICCS 420 610 960 µA

Circuit current ICCA 3.4 5.0 7.8 mA No load

【Output】

ON resistance RON 0.9 2.5 8.0 Ω Output rise/fall time Tr/Tf － 20 － nsec Cout=1000pF

Output source current IOUTSO － -0.80 － A

Output sink current IOUTSI － 0.85 － A

Ta=-40 to 85℃,VCC=4 to 9V, OUT=0V，rush current

Ta=-40 to 85℃,VCC=4 to 9V, OUT=VCC，rush current

【Under voltage lock out】

Threshold voltage VUT 3.7 3.8 3.9 V Vcc sweep down

Hysteresis width VUThy 0.05 0.10 0.15 V

Technical Note

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BD9763FVM

●Reference data (Unless otherwise specified, Ta=25℃)

[V]

VREF voltage

VREF　voltage　vs .　Ambient　temperature

2.53

2.52

2.51

2.5

2.49

2.48

2.47

-60 -40 -20 0 20 40 60 80 100 120 140

Ambient　temperature　 [℃]

Fig.1 VREF voltage – Ambient temperature

Oscillating　frequency　vs.　Ambient　temperature

650

640

630

[kHz]

frequency

Oscillating

RT=24kΩ

620

610

600

590

580

570

560

550

-60 -40 -20 0 20 40 60 80 100 120 140

Ambient　temperature　 [℃]

Fig.3 Oscillating frequency – Ambient temperature Fig.4 Oscillating frequency – Ambient temperature

(RT=24kΩ) (RT=10kΩ)

●Block diagram

Clamper

VREF

U.V.L.O

Vref

INV

5

Error

1.0V

Amp

FB

6

T.S.D

4

7

CTL/SS

Fig.5

Technical Note

Oscillating　frequency　vs.　Timing　 resistance

10000

1000

Oscillating　frequency 　 [kHz]

100

1 10 100 1000

Fig.2 Oscillating frequency – Timing resistance (R

1200

1180

1160

[kHz]

1140

1120

1100

frequency

1080

1060

1040

Oscillating

1020

1000

RTVCC

81

TRI

PWM

COMP

Vdt

Timing　resistance　(RT) 　[kΩ]

Oscillating　frequency　vs.　Ambient　temperature

RT=10kΩ

-60 -40 -20 0 20 40 60 80 100 120 140

Ambient　temperature　 [℃]

VCC

OUT

2

3

GND

RT)

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BD9763FVM

Technical Note

●Pin configuration

1pin

VCC

RT

8pin

2pin

OUT

CTL/SS

7pin

3pin

GND

FB

6pin

4pin

VREF

INV

5pin

Fig.6

●Pin number , Pin name

Pin No. Pin name Function

1 VCC Power supply

2 OUT FET driver output

3 GND Ground 4 VREF Reference voltage (2.5V±1%) output

5 INV Inverting input of error amplifier

6 FB Output of error amplifier

7 CTL/SS Stand-by switch/Soft start capacitor connecting pin

8 RT Timing resistor connecting pin

●Block description ・VOLTAGE REFERENCE(VREF) BLOCK

This voltage reference block generates 2.5V internal reference voltage.

・OSCILLATOR BLOCK

Oscillator block sets the oscillating frequency adjusted by an external resistance in RT pin. The oscillating frequency can be set within a range of 100~1200kHz.. (See the description of how to set the frequency on page6.)

・PWM COMP

The PWM comparator transforms the voltage outputted from error amp to PWM waveform and outputs to FET driver. The maximum duty cycle is limited up to 90%.

・ERROR AMP BLOCK

The error amp block detects the output voltage from the INV pin, amplifies the difference between the detected voltage and the reference voltage, and outputs it to FB pin. The reference voltage is 1V±2%.

・PROTECTION CIRCUIT BLOCK

The under voltage lock out circuit is activated to shut down the whole circuit when the VCC voltage is up to 3.8V. When the thermal shutdown circuit detects abnormal heating of the chip (150℃), the output becomes off. And the output turns back on when the chip temperature goes down to a specific level.

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