RT9173B
2.5V
VIN
3.3V
VCNTL
REFEN
RT9173B
V
OUT
C
1.25V
VOUT
A
V
GND
OUT
I
L
Figure 3. Current Limit for High Side, ΙCLHIGH
Power Supply
with Current Limit
3.3V
2.5V
A
VCNTL
VIN
I
L
RT9173B
REFEN
V
OUT
C
1.25V
VOUT
V
GND
OUT
Figure 4. Current Limit for Low Side, ΙCLLOW
3.3V
2.5V
VCNTL
VIN
RT9173B
REFEN
V
OUT
1.25V
VOUT
V
REFEN
GND
C
0.2V
V
OUT
R
L
1.25V
V
OUT
0V
V
V
would be low if V
< 0.2V
> 0.6V
OUT
OUT
REFEN
would be high if V
REFEN
RL and COUT
Time deleay
Figure 5. REFEN Pin Shutdown Threshold, VTRIGGER
DS9173B-09 March 2007
www.richtek.com
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