AST1S31HF Datasheet, PDF (1/33 Pages) STMicroelectronics – Internal soft-start and enable

AST1S31HF
Up to 4 V, 3 A step-down 2.3 MHz switching regulator for
automotive applications
Datasheet - production data
Applications
 Designed for automotive systems
 Battery powered applications
 Car body applications
Description
Features
 AECQ100 qualified
 3 A DC output current
 2.8 V to 4 V input voltage
 Output voltage adjustable from 0.8 V
 2.3 MHz switching frequency
 Internal soft-start and enable
 Integrated 70 m and 55 m power MOSFETs
 All ceramic capacitor
 Power Good (POR)
 Cycle-by-cycle current limiting
 Current foldback short-circuit protection
 VFDFPN 3 x 3 - 8L package
The AST1S31HF is an internally compensated
2.3 MHz fixed frequency PWM synchronous step-
down regulator. The AST1S31HF operates from
2.8 V to 4 V input, while it regulates an output
voltage as low as 0.8 V and up to V_IN.
The AST1S31HF device integrates a 70 m high-
side switch and a 55 m synchronous rectifier
allowing very high efficiency with very low output
voltages.
The peak current mode control with internal
compensation deliver a very compact solution
with a minimum component count.
The AST1S31HF is available in a 3 mm x 3 mm,
8-lead VFDFPN package.
Figure 1. Application circuit
L
VIN
VOUT
VINSW
SW
Cin_a
VINA
R3
EN
AST1S31HF
R1
Cin_sw
PG
GND
VFB
Cout
R2
March 2016
This is information on a product in full production.
DocID026968 Rev 2
1/33
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