MIC4690 Datasheet, PDF (1/12 Pages) Micrel Semiconductor – 500kHz 1A SuperSwitcher Buck Regulator

MIC4690
Micrel
MIC4690
500kHz 1A SuperSwitcher™ Buck Regulator
Final Information
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
• 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
Applications
• 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
Typical Application
SHUTDOWN
ENABLE
5V
212C0µVF1
MIC4690BM
2 _VIN
SW ³
Power
SOP-8
1 _SHDN
FB ⁴
GND
5Ð8
L1
10µH
D22A01V
2.5V/1A
R3.101k
R2.294k
C140V20µF
2.5V Adjustable Converter
4V to 30V
(34V Transient)
SHUTDOWN
ENABLE
212C0µ_VF1
MIC4690BM
2 _VIN
SW ³
Power
SOP-8
1 _SHDN
FB ⁴
GND
5Ð8
L1
18µH
D22A01V
1.8V/1A
R3.101k
R6.249k
C242V20_µF
SuperSwitcher is a trademark of Micrel, Inc.
1.8V Adjustable Converter
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com
June 2001
1
MIC4690