MIC26400 Datasheet, PDF (1/27 Pages) Micrel Semiconductor – 5A Hyper Speed Control Synchronous DC/DC Buck Regulator

MIC26400
5A Hyper Speed Control^TM
Synchronous DC/DC Buck Regulator
SuperSwitcher II^TM
General Description
The Micrel MIC26400 is a constant-frequency, synchronous
buck regulator featuring a unique digitally modified adaptive
ON-time control architecture. The MIC26400 operates over
an input supply range of 4.5V to 26V and provides a
regulated output at up to 5A of output current. The output
voltage is adjustable down to 0.8V with a typical accuracy of
±1%, and the device operates at a switching frequency of
300kHz.
Micrel’s Hyper Speed Control^TM architecture allows for ultra-
fast transient response while reducing the output capacitance
and also makes (High V_IN)/(Low V_OUT) operation possible.
This digitally modified adaptive t_ON ripple control architecture
combines the advantages of fixed frequency operation and
fast transient response in a single device.
The MIC26400 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.
All support documentation can be found on Micrel’s web
site at: www.micrel.com.
Features
• Hyper Speed Control^TM architecture enables
- High delta V operation (V_IN = 26V and V_OUT = 0.8V)
- Small output capacitance
• 4.5V to 26V input voltage
• Output down to 0.8V with ±1% accuracy
• Any Capacitor^TM Stable
- Zero ESR to high-ESR output capacitance
• 5A output current capability
• 300kHz switching frequency
• Internal compensation
• Up to 95% efficiency
• 6ms Internal soft-start
• Foldback current limit and “hiccup” mode short-circuit
protection
• Thermal shutdown
• Supports safe start-up into a pre-biased load
• –40°C to +125°C junction temperature range
• 28-pin 5mm X 6mm MLF^® package
Applications
• Distributed power systems
• Communications/networking infrastructure
• Set-top box, gateways and routers
• Printers, scanners, graphic cards and video cards
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Typical Application
Hyper Speed Control, SuperSwitcher II and Any Capacitor are trademarks of Micrel, Inc.
MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
July 2010
M9999-070110-A