MIC24055 Datasheet, PDF (1/29 Pages) Micrel Semiconductor – 12V, 12A High-Efficiency Buck Regulator

MIC24055
12V, 12A High-Efficiency Buck Regulator
SuperSwitcher II
General Description
Features
The Micrel MIC24055 is a constant-frequency,
synchronous buck regulator featuring a unique adaptive
on-time control architecture. The MIC24055 operates over
an input supply range of 4.5V to 19V and provides a
regulated output of up to 12A of output current. The output
voltage is adjustable down to 0.8V with a guaranteed
accuracy of ±1%, and the device operates at a switching
frequency of 600kHz.
• 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 from 0.8V to 5.5V
Micrel’s Hyper Speed Control architecture allows for
ultra-fast transient response while reducing the output
capacitance and also makes (High V_IN)/(Low V_OUT)
operation possible. This adaptive t_ON ripple control
architecture combines the advantages of fixed-frequency
operation and fast transient response in a single device.
The MIC24055 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, internal soft-start to reduce
inrush current, foldback current limit, “hiccup mode” short-
circuit protection and thermal shutdown. An open-drain
power good (PG) pin is provided.
The 12A HyperLight Load^® part, MIC24056, is also
available on Micrel’s web site.
• ±1% feedback accuracy
• Any Capacitor™ Stable – zero-to-high ESR
• 600kHz switching frequency
• No external compensation
• Power good (PG) output
• Foldback current-limit and “hiccup mode” short-circuit
protection
• Supports safe startup into a pre-biased load
• –40°C to +125°C junction temperature range
• Available in 28-pin 5mm × 6mm QFN package
Applications
• Server and work stations
All support documentation can be found on Micrel’s web _{• Routers, switches and telecom equipment}
site at: www.micrel.com.
• Base station
___________________________________________________________________________________________________________
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
M9999-120712-A