MIC4690
Micrel
MIC4690
500kHz 1A SuperSwitcher™ Buck Regulator
General Description
The MIC4690 SuperSwitcher™ is an easy-to-use, 500kHz
step-down PWM voltage regulator. The MIC4690 achieves
over 1A of continuous output current over a wide input voltage
range in an 8-lead SO (small outline) package.
The high switching frequency of the MIC4690 allows the
smallest surface-mount inductors and capacitors to be used.
Internal compensation ensures fast transient response and a
minimum amount of external components.
The MIC4690 features a power SO-8 package with a special
lead frame that allows over 1A of continuous current. The
MIC4690, housed in an SO-8, can replace larger TO-220 and
TO-263 packages in many applications.
The MIC4690 allows for a high degree of safety. It has a wide
input voltage range of 4V to 34V, allowing for it to be used in
applications where input voltage transients may be present.
Built-in safety features include over-current protection, fre-
quency foldback protection, and thermal shutdown.
The MIC4690 is available in an 8-lead SO package with a
junction temperature range of –40°C to +125°C.
Features
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SO-8 package with over 1A output current
Fixed 500kHz operation
Wide 4V to 34Vinput voltage range
Output voltage adjustable to 1.23V
All surface mount solution
Internally compensated with fast transient response
Up to 85% efficiency
Overcurrent protection
Frequency foldback short-circuit protection
Thermal shutdown
Simple 1A step-down (buck) regulator
Replacement of TO-220 and TO-263 designs
12V to 5V/3.3V/2.5V/1.8V/1.5V conversion
5V to 2.5V/1.8V/1.5V conversion
On-card switching regulators
Hard disk drives
Cable modems
Positive-to-negative converters
Simple battery chargers
Applications
Typical Application
5V
SHUTDOWN
ENABLE
2
C1
22µF
10V
VIN
MIC4690BM
Power
SOP-8
SW
FB
3
L1
10µH
D1
2A
20V
2.5V/1A
R1
3.01k
R2
2.94k
C2
100µF
4V
1
SHDN
GND
4
5Ð8
2.5V Adjustable Converter
4V to 30V
(34V Transient)
C1
22
µ
F
10V
SHUTDOWN
ENABLE
2
VIN
MIC4690BM
Power
SOP-8
SW
FB
3
L1
18
µ
H
D1
2A
20V
1.8V/1A
R1
3.01k
R2
6.49k
C2
220
µ
F
4V
1
SHDN
GND
4
5Ð8
1.8V Adjustable Converter
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
April 2005
1
MIC4690
MICREL [ MICREL SEMICONDUCTOR ]
