A5970D_08 Datasheet, PDF (1/13 Pages) STMicroelectronics – Up to 1 A step down switching regulator for automotive applications

A5970D
Up to 1 A step down switching regulator
for automotive applications
Features
■ Qualified following the AEC-Q100
requirements (temperature grade 3),
see PPAP for more details.
■ Up to 1 A DC output current
■ Operating input voltage from 4 V to 36 V
■ 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
■ Dedicated to automotive applications
Figure 1. Application schematic
SO-8
Description
The A5970D is a step down monolithic power
switching regulator capable to deliver up to 1 A at
output voltages from 1.2 V to 35 V.
The device uses an internal P-channel D-MOS
transistor (with a typical R_DS(on) 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.
Pulse by pulse current limit with the internal
frequency modulation offers an effective constant
current short circuit protection.
VIN=4.4V to 35V
C1
10uF
35V
CERAMIC
C4
22nF
C3
220pF
VCC
8
COMP
4
6
R3 ^VREF
3.3V
4k7
OUT
1
A5970D
7
SYNCH
2
FB
5
3
GND INH
L1 33uH
D1
STPS340U
Vout=3.3V
R1
5k6
C2
100uF
10V
R2
3k3
August 2008
Rev 4
1/12
www.st.com
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