MIC4680
Micrel
MIC4680
1A 200kHz SuperSwitcher™ Buck Regulator
Final Information
General Description
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-lead SOP (small outline package).
The MIC4680 is available in 3.3V and 5V fixed output ver-
sions 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 shut-
down for protection under fault conditions. In shutdown
mode, the regulator draws less than 2µA of standby current.
The MIC4680 SuperSwitcher™ regulator requires a mini-
mum number of external components and can operate using
a standard series of inductors and capacitors. Frequency
compensation is provided internally for fast transient re-
sponse and ease of use.
The MIC4680 is available in the 8-lead SOP with a
–40°C to +125°C junction temperature range.
Features
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SO-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
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Simple 1A high-efficiency step-down (buck) regulator
Replacement of TO-220 and TO-263 designs
Efficient preregulator (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 Applications
+6V to +34V
C1
15µF
35V
SHUTDOWN
ENABLE
2
MIC4680-3.3BM
IN
SW
3
L1
68µH
3.3V/1A
C2
220µF
16V
1
SHDN
GND
5–8
FB
4
Power
SOP-8
D1
B260A or
SS26
Fixed Regulator Circuit
MIC4680BM
IN
SW
+5V to +34V
C1
15µF
35V
SHUTDOWN
ENABLE
2
3
L1
68µH
R1
3.01k
R2
2.94k
2.5V/1A
C2
220µF
16V
1
SHDN
GND
5–8
FB
4
Power
SOP-8
D1
B260A or
SS26
Adjustable Regulator Circuit
SuperSwitcher is a trademark of Micrel, Inc.
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
June 2000
1
MIC4680
MICREL [ MICREL SEMICONDUCTOR ]
