A5973D_08 Datasheet, PDF (1/12 Pages) STMicroelectronics – Up to 2 A step down switching regulator for automotive applications

A5973D
Up to 2 A 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
■ 2 A DC output current
HSOP8 exposed pad
■ 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
■ Dedicated to automotive applications
Figure 1. Application schematic
Description
The A5973D is a step down monolithic power
switching regulator with a minimum switch current
limit of 2.25 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 HSOP8 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 DMOS 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. 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
C E R AM IC
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
May 2008
Rev 4
1/11
www.st.com
1