TECHNICAL NOTE

High-performance Regulator IC Series for PCs

Ultra Low Dropout

Linear Regulator Controllers

for PC Chipsets

BD3504FVM, BD3500FVM, BD3501FVM, BD3502FVM

●Description

The BD3500/01/02/04FVM is an ultra-low dropout linear regulator controller for chipset that can achieve ultra-low voltage

input to ultra-low voltage output. By using N-MOSFET for external power transistor, the controller can be used at ultra-low

I/O voltage difference up to voltage difference generated by ON resistance. In addition, because best suited power

transistor can be chosen in accord with the output current, downsizing and cost reduction of the set can be achieved.

Because by reducing the I/O voltage difference, large current output is achieved and conversion loss can be reduced,

switching power supply can be replaced. BD3500/01/02/04FVM does not need any choke coil, diode for rectification and

power transistor which are required for switching power supply, total cost of the set can be reduced and compact size can

be achieved for the set. Using external resistors, optional output from 0.65V to 2.5V can be set. In addition, since voltage

output start-up time can be adjusted by using the NRCS terminal, it is possible to flexibly meet the power supply sequence

of the set.

●Features

1) Reduced rush current by NRCS

2) Built-in driver for external Nch h transistor

3) Adoption of MSOP8 package: 2.9 x 4.0 x 0.9 (mm)

4) Built-in timer latch short protection circuit

5) Built-in low input maloperation prevention circuit

6) Output voltage variable type

7) Built-in overheat protection circuit

●Applications

Mobile PC, desktop PC, digital home appliances

●Line up

Parameter

BD3500FVM

BD3501FVM

BD3502FVM

BD3504FVM

Output Voltage

1.8V (Fix)

1.5V (Fix)

1.2V (Fix)

Variable(0.65～2.5V)

NRCS

(Soft start)

○

(Independent Setting)

○

(Independent Setting)

○

(Independent Setting)

○

(Same Timer Latch)

Timer latch short

protection circuit

○

(Independent Setting)

○

(Independent Setting)

○

(Independent Setting)

○

(Same NRCS)

Hysterisis

Hysterisis

Hysterisis

Detected at start-up only

(set by external resistor)

External FET

GATE Drive Current

+1/-3mA

+1/-3mA

+1/-3mA

+3/-3mA

Oct. 2008