UCC27221

UCC27222

SLUS486B − AUGUST 2001 − REVISED JULY 2003

11

www.ti.com

APPLICATION INFORMATION

systems with 5-V input only

The circuit pictured in Figure 6 starts up from a 5-V input bus and provides a 6.5-V gate drive to the power

and apply this to the input of the linear regulator. The regulator then regulates the doubled input voltage to the

6.5-V nominal for VLO.

CIN

C2

C1

PWM

Input

D1

GND

+5V

VHI

G1

SW

SWS

PVLO

N/C

VDD

VLO

G2S

G2

PGND

AGND

IN

N/C

UCC27222

L1

Cout

Q1

Q2

V OUT

GND

C4

D3

D4

D2

C3

Figure 6. System Application: 5-V-Only Power Input with 6.5-V Gate Drive Using Charge Pump Circuit