Rainbow Electronics BA3257FP-HFP User Manual

Dual Low Drop Out Regulator

Ceramic Capacitor Available

BA3257FP/HFP

Description
BA3257FP/HFP is a power supply IC in which

2-output series regulators are incorporated into
a power package (TO252-5/HRP-5). 2-outputs
are 3.3V and a variable output.(Above 1.5V can
be set.) Each current is 1A. Ceramic capacitor
is available for output.

Features

1) 3.3V/1A and Variable(1.25V standard)/1A

2) Output ceramic capacitor available

3) Output voltage accuracy :+/-2%

4) Built-in over-current and thermal protection circuit

5) TO252-5 package and HRP-5 package

Applications

HDD/DVD

Dimension (Unit : mm)

BA3257FP

6.5±0.2

+0.2

5.1

−0.1

1.5±0.2

2-C0.5

5.5±0.2

123 54

0.8

0.5

TO252-5

BA3257HFP

9.39±0.125

8.82±0.1
(5.59)

1.017±0.28.0±0.13

1 2 3 4 5

1.2575

2.3±0.2

0.5±0.1

9.5±0.5

1.5

1.27

2.5

0.5±0.1

1.0±0.2

1.905±0.1

(7.49)

10.54±0.13

0.835±0.2

1.523±0.15

+ 5.5°

4.5°

− 4.5°

+ 0.1

0.27

− 0.05

Absolute Maximum Ratings (Ta=25˚C)

Parameter Symbol

Power supply voltage

Power
dissipation

HRP-5

TO252-5

Operating temperature range

Storage temperature range

∗1 Derating : 18.4mW/˚C for operation above Ta=25˚C PCB (70mmx70mm, t=1.6mm) glass epoxy mounting.
∗2 Derating : 10.4mW/˚C for operation above Ta=25˚C PCB (70mmx70mm, t=1.6mm) glass epoxy mounting.

VCC

Pd

Topr

Tstg

Limits

15
2300
1300

0

-

55

+85

~

+150

~

∗1

∗2

Recommended Operating Conditions (Ta=25˚C)

Parameter Min. Max. UnitTyp.Symbol

Power supply voltage VCC

4.75 14.0 V

-

Unit

V

mW

˚C
˚C

1.72

0.08±0.05

0.73±0.1

SSD 0.08

HRP-5

Electrical characteristics (Unless otherwise noted; Ta=25˚C, Vcc=5V, R1=R2=5kΩ)

Parameter Symbol Min. Typ. Max. Unit Conditions
Circuit current
Line regulation 1,2
Load regulation 1,2

Ib

∆VLINE1,2

∆

VLOAD1,2

-

-

-

3
5
5

5
15
20

Io1=0mA, Io2=0mA

mA

Vcc=4.75 → 14V, Io1=5mA

mV

Io2=5mA → 1A

mV
[3.3V output]
Output voltage
Dropout voltage
Output current

[Variable output]
Reference voltage
Dropout voltage
Output current

Vo1

∆

VD1

Io1

Vref

∆

VD2

Io2

3.234

-

1.0

1.225

-

1.0

3.300

1.1

-



1.250

1.1

-

3.366

1.3

­

1.275

1.3

-

Io1=50mA

V

Io1=1A

V
A

Io2=50mA

V

Io2=1A, R1=8.2kΩ, R2=5kΩ

V
A

Application Circuit

VO1 3.3V

Current

Limit

5

CO1
1µF

GND

FIN

Thermal

Shutdown

Current

Limit

VREF

BA3257FP/HFP

VOUT2=VREF X (1+R1/R2)+IADJ X R1

VO2

4

ADJ

2

VCC

1

ADJ

CO2
1µF

R1

R2

VIN

CIN

3.3µF