UM3501_15 Datasheet, PDF (6/11 Pages) Union Semiconductor, Inc. – 600mA, 1.2MHz, Synchronous Step-Down DC-DC Converter

UM3501
Typical Performance Characteristics (continued)
(V_IN = 3.6V, V_OUT = 1.8V, L1= 2.2µH, C1= 4.7µF, C3= 10µF, T_A = +25°C, unless otherwise
noted.)
Light Load Operation
(Vout=1.8V, Io=0mA)
SW
Heavy Load Operation
(Vout=1.8V, Io=200mA)
SW
VOUT 20mV/div 5ms/div
VOUT 20mV/div 500ns/div
Block Diagram
OSC
SLOPE
COMP
I SENSE
AMP
_
SQ
0.6V
+
FB
EA
-
ICOMP
+
__
RQ
4
-
RS LATCH
PWM
LOGIC
DRV
VIN
EN
3
REF
0.6V
I ZERO
COMP
VIN
1
VIN
2.5~5.5V
SW
5
VOUT
R2
COUT
R1
2
GND
Function Description
UM3501 is a monolithic switching mode Step-Down DC-DC converter. It utilizes internal
MOSFETs to achieve high efficiency and can generate very low output voltage by using internal
reference at 0.6V. It operates at a fixed switching frequency, and uses the slope compensated
current mode architecture. This Step-Down DC-DC Converter supplies 600mA output current at
V_IN =3.6V with input voltage range from 2.5V to 5.5V.
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http://www.union-ic.com Rev.06 Feb.2015
6/11