PM6675S Datasheet, PDF (1/53 Pages) STMicroelectronics – High efficiency step-down controller with embedded 2 A LDO regulator

PM6675S
High efficiency step-down controller
with embedded 2 A LDO regulator
Features
■ Switching section
– 4.5 V to 28 V input voltage range
– 0.6 V, ±1 % voltage reference
– Selectable 1.5 V fixed output voltage
– Adjustable 0.6 V to 3.3 V output voltage
– 1.237 V ±1 % reference voltage available
– Very fast load transient response using
constant on-time control loop
– No R_SENSE current sensing using low side
MOSFETs' R_DS(ON)
– Negative current limit
– Latched OVP and UVP
– Soft-start internally fixed at 3 ms
– Selectable pulse skipping at light load
– Selectable No-Audible (33 kHz) pulse skip
mode
– Ceramic output capacitors supported
– Output voltage ripple compensation
– Output soft-end
■ LDO regulator section
– Adjustable 0.6 V to 3.3 V output voltage
– Selectable ±1 Apk or ±2 Apk current limit
– Dedicated power-good signal
– Ceramic output capacitors supported
– Output soft-end
Applications
■ Notebook computers
■ Graphic cards
■ Embedded computers
VFQFPN-24 4x4
Description
The PM6675S device consists of a single high
efficiency step-down controller and an
independent Low Drop-Out (LDO) linear
regulator.
The Constant On-Time (COT) architecture
assures fast transient response supporting both
electrolytic and ceramic output capacitors. An
embedded integrator control loop compensates
the DC voltage error due to the output ripple.
A selectable low-consumption mode allows the
highest efficiency over a wide range of load
conditions. The low-noise mode sets the minimum
switching frequency to 33 kHz for audio-sensitive
applications.
The LDO linear regulator can sink and source up
to 2 Apk. Two fixed current limits (±1 A-±2 A) can
be chosen.
An active soft-end is independently performed on
both the switching and the linear regulators
outputs when disabled.
Table 1. Device summary
Order codes
PM6675S
PM6675STR
Package
VFQFPN-24 4x4 (exposed pad)
Packaging
Tube
Tape and reel
February 2008
Rev 1
1/53
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