MIC24056 Datasheet, PDF (1/30 Pages) Micrel Semiconductor – 12V, 12A High-Efficiency Buck Regulator

MIC24056
12V, 12A High-Efficiency Buck Regulator
SuperSwitcher II
General Description
Features
The Micrel MIC24056 is a constant-frequency,
synchronous DC/DC buck regulator featuring adaptive on-
time control architecture. The MIC24056 operates over a
supply range of 4.5V to 19V. It has an internal linear
regulator which provides a regulated 5V to power the
internal control circuitry. MIC24056 operates at a constant
600kHz switching frequency in continuous-conduction
mode and can be used to provide up to 12A of output
current. The output voltage is adjustable down to 0.8V.
Micrel’s HyperLight Load^® architecture provides the same
high efficiency and ultra-fast transient response as the
Hyper Speed Control architecture under medium to
heavy loads, but also maintains high efficiency under light
load conditions by transitioning to variable frequency,
discontinuous mode operation.
The MIC24056 offers a full suite of protection features to
ensure protection of the IC during fault conditions. These
include undervoltage lockout to ensure proper operation
under power-sag conditions, thermal shutdown, internal
soft start to reduce the inrush current, foldback current-
limit and “hiccup” mode short-circuit protection. The
MIC24056 includes a power good (PG) output to allow
simple sequencing.
The 12A Hyper Speed Control part, MIC24055, is also
available on Micrel’s web site.
All support documentation can be found on Micrel’s web
site at: www.micrel.com.
• HyperLight Load efficiency – up to 80% at 10mA
• Hyper Speed Control architecture enables
− High delta V operation (V_IN = 19V and V_OUT = 0.8V)
− Small output capacitance
• Input voltage range: 4.5V to 19V
• Output current up to 12A
• Up to 95% efficiency
• Adjustable output voltage from 0.8V to 5.5V
• ±1% FB accuracy
• Any Capacitor™ stable − zero-to-high ESR
• 600kHz switching frequency
• Power good (PG) output
• Foldback current-limit and “hiccup” mode short-circuit
protection
• Safe start-up into pre-biased loads
• –40°C to +125°C junction temperature range
• Available in 28-pin 5mm × 6mm QFN package
Applications
• Servers, work stations
• Routers, switches, and telecom equipment
• Base stations
___________________________________________________________________________________________________________
Typical Application
100
95
90
85
80
75
70
65
60
55
50
0
Efficiency (VIN = 12V)
vs. Output Current
5.0V
3.3V
2.5V
1.8V
1.5V
1.2V
1.0V
0.9V
0.8V
VIN = 12V
3
6
9
12
15
OUTPUT CURRENT (A)
HyperLight Load is a registered trademark of Micrel, Inc.
Hyper Speed Control, SuperSwitcher II, and Any Capacitor are trademarks of Micrel, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
December 2012
M9999-121012-A