A5973D Datasheet, PDF (1/13 Pages) STMicroelectronics – 2.5A switch step down switching regulator for automotive applications

A5973D
2.5A switch step down switching regulator
for automotive applications
Features
■ Qualified following the AEC-Q100
requirements (temperature Grade 3), see
PPAP for more details.
■ Temperature range -40°C to 85°C
■ 2A DC output current
■ Operating input voltage from 4V to 36V
■ 3.3V / (±2%) reference voltage
■ Output voltage adjustable from 1.235V to 35V
■ Low dropout operation: 100% duty cycle
■ 250kHz 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
■ Dedicated to automotive applications
Figure 1. Typical application
HSOP8 exposed pad
Description
The A5973D is a step down monolithic power
switching regulator with a minimum switch current
limit of 2.5A so it is able to deliver more than 2A
DC current to the load depending on the
application conditions. The output voltage can be
set from 1.235V to 35V. The high current level is
also achieved thanks to an SO8 package with
exposed frame, that allows to reduce the
R_th(JA) down to approximately 40°C/W. 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
external components. An internal oscillator fixes
the switching frequency at 250kHz. Having a
minimum input voltage of 4V only, it is particularly
suitable for 5V bus. Pulse by pulse current limit
with the internal frequency modulation offers an
effective constant current short circuit protection.
Pulse by pulse current limit with the internal
frequency modulation offers an effective constant
current short circuit protection.
VIN=4V to 35V
C1
10uF
35V
CERAMIC
C4
22nF
C3
220pF
VCC
8
COMP
4
6
R3 ^VREF
3.3V
4k7
OUT
1
A5973D
7
SYNCH
2
FB
5
3
GND INH
L1 15uH
D1
STPS340U
Vout=3.3V
R1
5k6
C2
330uF
6.3V
R2
3k3
October 2007
Rev 2
1/14
www.st.com
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