Datasheet MIC4680 (Microchip)

MIC4680
1A 200kHz SuperSwitcher™
Buck Regulator General Description Features The MIC4680 SuperSwitcher™ is an easy-to-use fixed or
adjustable output voltage step-down (buck) switch-mode
voltage regulator. The 200kHz MIC4680 achieves up to
1.3A of continuous output current over a wide input range
in a 8-pin SOIC.
The MIC4680 is available in 3.3V and 5V fixed output
versions or adjustable output down to 1.25V.
The MIC4680 has an input voltage range of 4V to 34V,
with excellent line, load, and transient response. The
regulator performs cycle-by-cycle current limiting and
thermal shutdown for protection under fault conditions. In
shutdown mode, the regulator draws less than 2µA of
standby current.
The MIC4680 SuperSwitcher™ regulator requires a minimum number of external components and can operate
using a standard series of inductors and capacitors.
Frequency compensation is provided internally for fast
transient response and ease of use.
The MIC4680 is available in the 8-pin SOIC with a
–40°C to +125°C junction temperature range. •
•
•
•
•
•
•
•
•
•
• SOIC-8 package with up to 1.3A output current
All surface mount solution
Only 4 external components required
Fixed 200kHz operation
3.3V, 5V, and adjustable output versions
Internally compensated with fast transient response
Wide 4V to 34V operating input voltage range
Less than 2µA typical shutdown-mode current
Up to 90% efficiency
Thermal shutdown
Overcurrent protection Applications
•
•
•
•
•
•
•
• Simple 1A high-efficiency step-down (buck) regulator
Replacement of TO-220 and TO-263 designs
Efficient pre-regulator (5V to 2.5V, 12V to 3.3V, etc.)
On-card switching regulators
Positive-to-negative converter (inverting buck-boost)
Simple battery charger
Negative boost converter
Higher output current regulator using external FET Typical Application
+6V to +34V
C1
15µF
35V
SHUTDOWN
ENABLE Power
SOIC-8 MIC4680-3.3BM
2 1 IN
SHDN SW 3 FB 4 L1
68µH GND
5–8 D1
B260A or
SS26 Fixed Regulator Circuit 3.3V/1A
C2
220µF
16V +5V to +34V
C1
15µF
35V
SHUTDOWN
ENABLE Power
SOIC-8 2 1 MIC4680BM
IN
SW
SHDN FB GND
5–8 3 L1 2.5V/1A 68µH R1
3.01k 4 D1
B260A or
SS26 R2
2.94k C2
220µF
16V Adjustable Regulator Circuit SuperSwitcher is a trademark of Micrel, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com March 2008 M9999-032808