A5974AD Datasheet, PDF (1/49 Pages) STMicroelectronics – Zero load current operation

A5974AD
Up to 2 A step-down switching regulator
for automotive applications
Features
■ Qualified following the AEC-Q100
requirements (see PPAP for more details)
■ 2 A DC output current
■ 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
■ 500 kHz internally fixed frequency
■ Voltage feed-forward
■ Zero load current operation
■ Internal current limiting
■ Inhibit for zero current consumption
■ Synchronization
■ Protection against feedback disconnection
■ Thermal shutdown
Application
■ Dedicated to automotive applications
Figure 1. Application schematic
HSOP8 - exposed pad
Description
The A5974AD is a step-down monolithic power
switching regulator with a minimum switch current
limit of 2.5 A, it is therefore able to deliver up to 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 a HSOP8 package with
exposed frame, that allows to reduce the R_THJ-A
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 500 kHz. Having a minimum input voltage of
only 4 V, it fits automotive applications requiring
device operation even in cold crank conditions.
Pulse-by-pulse current limit with the internal
frequency modulation offers an effective constant
current short-circuit protection.
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April 2011
Doc ID 018762 Rev 1
1/49
www.st.com
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