RT8238A
3
RT8238A-07 January 2014
www.richtek.com
©
Copyright 2014 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
Function Block Diagram
Min. t
OFF
Q
TRIG
1-SHOT
+
-
COMP
0.5V V
REF
S1
Q
Latch
S1
Q
Latch
+
-
OV
+
-
UV
125% V
REF
70% V
REF
+
-
125% V
REF
Thermal
Shutdown
DEM/FCCM
/ASM
DRV
DRV
On-time
Compute
1-SHOT
FB
VCC
UGATE
PHASE
PGOOD
GND
LGATE
TON
BOOT
TRIG
EN
R
Q
S
X(-1/10)
+
-
PWM
MODE
+
-
90% V
REF
SS
Timer
POR
CS
VCC
PHASE
10µA
Pin No.
Pin Name
Pin Function
9
PGOOD
Open Drain Power Good Indicator. High impedance indicates power is good.
10 CS
Current Limit Threshold Setting Input. Connect a setting resistor to GND and the
current limit threshold is equal to 1/10 of the voltage at this pin.
11
TON
On-time Setting. Connect a resistor between this pin and V
IN
.
12,
13 (Exposed Pad)
GND
Ground. The exposed pad must be soldered to a large PCB and connected to
GND for maximum power dissipation.
