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E-L293DD Datasheet, PDF (1/17 Pages) STMicroelectronics – 2.5 A switch step down switching regulator
L5973D
2.5 A switch step down switching regulator
Features
■ 2.5 A internal switch
■ Operating input voltage from 4 V to 36 V
■ 3.3 V / (±2%) reference voltage
■ Output voltage adjustable from 1.235 V to 35 V
■ Low dropout operation: 100 % duty cycle
■ 250 kHz internally fixed frequency
■ Voltage feedforward
■ Zero load current operation
■ Internal current limiting
■ Inhibit for zero current consumption
■ Synchronization
■ Protection against feedback disconnection
■ Thermal shutdown
Applications
■ Consumer: STB, DVD, TV, VCR, car radio,
LCD monitors
■ Networking: XDSL, modems, DC-DC modules
■ Computer: printers, audio/graphic cards,
optical storage, hard disk drive
■ Industrial: changers, car battery, DC-DC
converters
Figure 1. Test application circuit
HSOP8 exposed pad
Description
The L5973D is a step down monolithic power
switching regulator with a minimum switch current
limit of 2.5 A so it is able to deliver more than 2 A
DC current to the load depending on the
application conditions.
The output voltage can be set from 1.235 V to
35 V. The high current level is also achieved
thanks to an SO8 package with exposed frame,
that allows to reduce the Rth(j-amb) down to
approximately 40 °C/W.
The device uses an internal P-channel D-MOS
transistor (with a typical Rdson of 250 mΩ) as
switching element to minimize the size of the
external components.
An internal oscillator fixes the switching frequency
at 250 kHz.
Having a minimum input voltage of 4 V only, it is
particularly suitable for 5 V bus, available in all
computer related applications.
Pulse by pulse current limit with the internal
frequency modulation offers an effective constant
current short circuit protection.
VREF
3.3V
6
1
VIN = 4.4V to 35V
VCC
8 L5973D
SYNC. 2
C1
10µF
35V
CERAMIC
COMP
C4
22nF
4
3
INH
C3
220pF
R3
4.7K
5
7
GND
OUT
FB
L1 15µH
D1
STPS340U
VOUT=3.3V
R1
5.6K
R2
3.3K
C2
330µF
10V
January 2008
D03IN1439
Rev 16
1/17
www.st.com
17