BA3259HFP(2009) Просмотр технического описания (PDF) - ROHM Semiconductor

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Компоненты Описание

производитель

BA3259HFP
(Rev.:2009)

Dual-output Secondary Fixed/Variable Output LDO Regulators for Local Power Supplies

ROHM Semiconductor 

BA3259HFP,BA30E00WHFP

Technical Note

Block Diagrams / Standard Example Application Circuits

Current

Limi t

VO1

5

3.3V

CO1

1μF

GND

FIN

Therm al

Shutdown

Current

Limi t

VR EF

VO2

4

GND

3

1.5V

CO2

1μF

ADJ

2

Vcc

1

R2

R1

VIN

CIN

3.3μF

Reference

Voltage

Thermal

Shut Down

GND(Fin)

Vcc1

Vcc1

Current

Limit

Sat.

Prevention

Vcc2

Vcc2

Current

Limit

Sat.

Prevention

EN 1

Vcc2 2

1μF

Vcc1 3 GND 4 Vo1 5 Vo2 6 ADJ 7

1μF

47μF 47μF R2 R1

Fig.25 BA3259HFP Block Diagram

Pin No.

1

2

3

4

5

FIN

Pin name

Vcc

ADJ

GND

Vo2

Vo1

GND

Function

Power supply pin

Variable output voltage detection pin

GND pin

Variable output pin

3.3 V output pin

GND pin

PIN

Vcc (1Pin)

Vo1 (5Pin)

Vo2 (4Pin)

External capacitor setting range

Approximately 3.3 F

1 F to 1000 F

1 F to 1000 F

TOP VIEW

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Fig.26 BA30E00WHFP Block Diagram

Pin No. Pin name

Function

1

EN

Output on/off control pin: High active

2

Vcc2 Power supply pin 2

3

Vcc1 Power supply pin 1

4

GND GND pin

5

Vo1

Power supply pin for 3.3 V output

6

Vo2

Variable output voltage detection pin (0.8 V to 3.3 V)

7

ADJ

Variable output voltage detection pin

FIN

GND GND pin

PIN

External capacitor setting range

TOP VIEW

Vcc1 (3Pin)

Approximately 1 F

Vcc2 (2Pin)

Approximately 1 F

Vo1 (5Pin)

47 F to 1000 F

Vo2 (6Pin)

47 F to 1000 F

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Setting the Output Voltage Vo2

The following output voltage setting method applies to the variable output pin.

Vo2=VADJ  ( 1 +

R2

R1

) - R2  IADJ

VADJ: Output feedback reference voltage (0.8 V typ.)

IADJ: ADJ pin source current

(0.05A typ.: BA3259HFP)

(0.2A typ.: BA30E00WHFP)

Vo2

ADJ

IADJ

R2

VADJ

R1

R1

BA3259HFP: 1 k to 10 k

BA30E00HFP: 1 k to 5 k

The above is recommended.

Note:Connect R1 and R2 to make output voltage settings as shown in Fig.25 and Fig.26. Keep in mind that the offset

voltage caused by the current (IADJ) flowing out of the ADJ pin will become high if higher resistance is used.

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© 2009 ROHM Co., Ltd. All rights reserved.

5/9

2009.04 - Rev.A

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