LTC1504A_15 Datasheet, PDF (1/12 Pages) Linear Technology – 500mA Low Voltage Step-Down Synchronous Switching Regulator

LTC1504A
500mA Low Voltage
Step-Down Synchronous
Switching Regulator
FEATURES
s _{500mA Output Current at 3.3V Output}
s _{Up to 92% Peak Efficiency}
s _{100% Maximum Duty Cycle}
s _{Internal Reference Trimmed to 1%}
s _{Output Can Source or Sink Current}
s _{Requires as Few as Four External Components}
s _{Input Voltage Range: 4V to 10V}
s _{Adjustable Current Limit}
s _{Small SO-8 Package}
s _{200kHz Switching Frequency Can Typically be}
Synchronized Up to 500kHz
U
APPLICATION_DS_{aisy-Chained Control Outputs}
s _{Small Portable Digital Systems}
s _{Active Termination}
s _{Auxiliary Output Voltage Supplies}
s _{Minimum Part Count/Size Switchers}
DESCRIPTION
The LTC^®1504A is a self-contained, high efficiency syn-
chronous buck switching regulator. It includes a pair of
on-chip 1.3Ω power switches, enabling it to supply up to
500mA of load current. Efficiency peaks at 92%, minimiz-
ing heat and wasted power. The synchronous buck archi-
tecture allows the output to source or sink current as
required to keep the output voltage in regulation. 100%
duty cycle operation minimizes dropout voltage.
The LTC1504A is available in adjustable and fixed 3.3V
output versions. An adjustable current limit circuit pro-
vides protection from overloads. The internal 1% refer-
ence combined with a sophisticated voltage feedback loop
provides optimum output voltage accuracy and fast load
transient response. The LTC1504A is specified to operate
with input voltages between 4V and 10V. Contact the LTC
factory for guaranteed specifications at 2.7V supply.
The LTC1504A is a pin-compatible, functional upgrade to
the LTC1504.
The LTC1504A is available in a plastic SO-8 package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
Minimum Part Count 5V to 3.3V Regulator
NC SHUTDOWN
5V ₊
C_IN
22µF
I_MAX
V_CC
SHDN
SW
LTC1504A-3.3
GND
SENSE
SS
COMP
L_EXT
50µH
+
C_IN: AVX TPSC226M016R0375
NC
C_OUT: AVX TAJC476M010
L_EXT: COILTRONICS CTX50-1P
1000pF
3.3V AT 500mA
C_OUT
47µF
1504A • TA01
100
90
80
70
60
50
40
30
20
10
0
10
5V to 3.3V Efficiency
100
LOAD CURRENT (mA)
500
1504 • TA02
1