L5970D Datasheet, PDF (1/10 Pages) STMicroelectronics – UP TO 1A STEP DOWN SWITCHING REGULATOR

L5970D
UP TO 1A STEP DOWN SWITCHING REGULATOR
s UP TO 1A OUTPUT CURRENT
s OPERATING INPUT VOLTAGE FROM 4.4V
TO 36V
s 3.3V / (±2%) / REFERENCE VOLTAGE
s OUTPUT VOLTAGE ADJUSTABLE FROM
1.2V TO 35V
s LOW DROPOUT OPERATION: 100% DUTY
CYCLE
s 250KHz INTERNALLY FIXED FREQUENCY
s VOLTAGE FEEDFORWARD
s ZERO LOAD CURRENT OPERATION
s INTERNAL CURRENT LIMITING
s INHIBIT FOR ZERO CURRENT
CONSUMPTION
s SINCHRONIZATION
s PROTECTION AGAINST FEEDBACK
DISCONNECTION
s THERMAL SHUTDOWN
APPLICATIONS:
s CONSUMER: STB, DVD, TV, VCR,CAR
RADIO, LCD MONITORS
s NETWORKING: XDSL, MODEMS,DC-DC
MODULES
s COMPUTER: PRINTERS, AUDIO/GRAPHIC
CARDS, OPTICAL STORAGE, HARD DISK
DRIVE
s INDUSTRIAL: CHARGERS, CAR BATTERY
DC-DC CONVERTERS
TEST APPLICATION CIRCUIT
SO8
ORDERING NUMBERS: L5970D (SO8)
L5970D013TR (T&R)
DESCRIPTION
The L5970D is a step down monolithic power
switching regulator capable to deliver up to 1A at
output voltages from 1.2V to 35V.
The device uses an internal P-Channel D-MOS
transistor (with a typical Rdson of 250mΩ) as
switching element to minimize the size of the ex-
ternal components.
An internal oscillator fixes the switching frequency
at 250KHz.
Having a minimum input voltage of 4.4V only, it is
particularly suitable for 5V bus, available in all
computer related applications.
Pulse by pulse current limit with the internal fre-
quency modulation offers an effective constant
current short circuit protection.
VREF
3.3V
6
1
VIN = 4.4V to 35V
VCC
8 _L5970D
SYNC. 2
C1
10µF
35V
CERAMIC
COMP
C4
22nF
4
3
INH.
C3
220pF
R3
4.7K
5
7
GND
OUT ^{L1 33µH}
VOUT=3.3V
D1
STPS2L40U ^R1
FB
5.6K
C2
100µF
10V
R2
3.3K
D98IN954C
May 2003
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