PM6675AS Datasheet, PDF (1/48 Pages) STMicroelectronics – High efficiency step-down controller with embedded 2 A LDO regulator

PM6675AS
High efficiency step-down controller
with embedded 2 A LDO regulator
Features
■ Switching section
– 4.5 V to 36 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
VFQFPN-24 4x4
Description
The PM6675AS 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.
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 limit
(±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.
■ Industrial application on 24 V
■ Graphic cards
■ Embedded computer systems
Table 1. Device summary
Order codes
Package
Packaging
PM6675AS
PM6675ASTR
VFQFPN-24 4x4 (exposed pad)
Tube
Tape and reel
February 2008
Rev 1
1/48
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