L5972D Datasheet, PDF (1/10 Pages) STMicroelectronics – 2A SWITCH STEP DOWN SWITCHING REGULATOR

L5972D
2A SWITCH STEP DOWN SWITCHING REGULATOR
s 2A INTERNAL SWITCH
s OPERATING INPUT VOLTAGE FROM 4.4V
TO 36V
s OUTPUT VOLTAGE ADJUSTABLE FROM
1.235V 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 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
SO8 (4+2+2)
ORDERING NUMBERS: L5972D (SO8)
L5972D013TR (Tape & Reel)
DESCRIPTION
The L5972D is a step down monolithic power switch-
ing regulator with a minimum switch current limit of
2A so it is able to deliver more than 1.5A DC current
to the load depending on the application conditions.
The output voltage can be set from 1.235V to 35V.
The device uses an internal P-Channel D-MOS tran-
sistor (with a typical Rdson of 250mΩ) as switching
element to minimize the size of the external compo-
nents.
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 com-
puter related applications.
Pulse by pulse current limit with the internal frequen-
cy modulation offers an effective constant current
short circuit protection.
TEST APPLICATION CIRCUIT
VIN = 4.4V to 35V
VCC
8
C1
10µF
35V
CERAMIC
COMP
4
C4
6
22nF
C3
220pF
R3
4.7K
L5972D
OUT
1
L1 33µH
D1
STPS2L40U
5
237
FB
GND
VOUT=3.3V
R1
5.6K
R2
3.3K
C2
100µF
10V
May 2003
D03IN1436
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