MIC2174 Datasheet, PDF (1/24 Pages) Micrel Semiconductor – 300kHz, Synchronous Buck Controller 300kHz, Synchronous Buck Controller

MIC2174
300kHz, Synchronous Buck Controller
Featuring Adaptive On-Time Control
General Description
Features
The Micrel MIC2174 is a fixed frequency, synchronous
buck controller featuring adaptive on-time control. The
MIC2174 operates over an input supply range of 3V to
40V, switches at a constant frequency of 300kHz and is
capable of driving 25A of output current. The output
voltage is adjustable down to 0.8V.
• Hyper Speed Control™ architecture enables
– High delta V operation (V_IN=40V and V_OUT=0.8V)
– Smaller output capacitors than competitors
• 3V to 40V input voltage
• Stable with zero-ESR output capacitor
A unique 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. The MIC2174 utilizes a adaptive T_ON ripple
controlled architecture. A UVLO is provided to ensure
proper operation under power-sag conditions to prevent
the external power MOSFET from overheating. A soft start
is provided to reduce inrush current. Foldback current limit
and “hiccup” mode short-circuit protection ensure FET and
load protection.
The MIC2174 is available in a 10-pin MSOP (MAX1954A-
compatible) package with a junction operating range from
–40°C to +125°C.
• 300kHz switching frequency
• Output down to 0.8V with ±1% FB accuracy
• Up to 94% efficiency
• Foldback current limit and “hiccup” mode short-circuit
protection
• 6ms Internal soft start
• Thermal shutdown
• Pre-bias output safe
• –40°C to +125°C junction temperature range
• Available in 10-pin MSOP package
Applications
All support documentation can be found on Micrel’s web _{• Wide input power supply}
site at: www.micrel.com.
• Industrial Equipments
• Distributed DC power systems
• Automotive applications
• PCs and servers
____________________________________________________________________________________________________________
Typical Application
MIC2174: Synchronous Buck Controller Featuring Adaptive On-Time Control
100
95
90
85
80
75
70
65
60
55
50
0
12V to 3.3V Efficiency
VIN=5V
2
4
6
8
10
OUTPUT CURRENT (A)
Hyper Speed Control is a trademark 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
September 2009
M9999-090409-B