Device description

L6731B

12/24

5.5

Error amplifier

5.6

Soft start

the start-up phase takes place. Otherwise the SS pin is internally shorted to GND. At start-up, a

initial value for this current is 35µA and charges the capacitor up to 0.5V. After that it becomes

10µA until the final charge value of approximately 4V (see Figure 6.).

Figure 5.

Error Amplifier Reference

Figure 6.

Device start-up: Voltage at the SS pin.

2.5V

100K

DDR-IN

0.6V/500KHz

0.6V/250KHz

DDR-IN/2

250KHz

Error Amplifier Ref.

t

t

0.5V

4V

Vcc

Vin

Vss

4.2V

1.25V