US3021B Datasheet, PDF (6/8 Pages) UNISEM – 5 BIT PROGRAMMABLE SYNCHRONOUS BUCK PLUS TRIPPLE LDO CONTROLLER

US3021B
BLOCK DIAGRAM
V12
V5
SD
Vsen1
PGood
Vsen3
Vsen4
Fix
Vaux
Drive4
Drive3
Select
Drive2
Vsen2
Enable
UVLO
R
1.26V
3R
1.17Vset
V12
Over
Voltage
Vset
Enable
1.1Vset
PWM
+
Control
V12
Slope
Comp
Osc
0.9Vset
Enable
Soft
Start &
Fault
Logic
Over
Current
200uA
Vset
1.5V
3.3V
R
3R
5Bit
DAC
Fb
UGate
LGate
Phase
OCSet
PGnd
Gnd
Fault / Rt
SS
VID0
VID1
VID2
VID3
VID4
3021Bblk1-1.4
Figure 1 - Simplified block diagram of the US3021.
4-6
Rev. 1.4
12/8/00