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MIC2169B_10 Datasheet, PDF (1/25 Pages) Micrel Semiconductor – 500kHz PWM Synchronous Buck Control IC | |||
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MIC2169B
500kHz PWM Synchronous Buck
Control IC
General Description
Features
The MIC2169B is a high-efficiency, simple to use 500kHz
PWM synchronous buck control IC housed in small
MSOP-10 and MSOP-10 ePad packages. The MIC2169B
allows compact DC/DC solutions with a minimal external
component count and cost. The device features high-
output driver capability to drive loads up to 30A.
⢠3V to 14.5V input voltage range
⢠Adjustable output voltage down to 0.8V
⢠500kHz PWM operation
⢠Up to 95% efficiency
⢠Output Pre-biased Protection
The MIC2169B operates from a 3V to 14.5V input, without
the need of any additional bias voltage. The output voltage
can be precisely regulated down to 0.8V. The adaptive all
N-Channel MOSFET drive scheme allows efficiencies over
95% across a wide load range within the smallest possible
printed circuit board space area.
The MIC2169B senses current across the high-side N-
Channel MOSFET, eliminating the need for an expensive
and lossy current-sense resistor. Current-limit accuracy is
maintained by a positive temperature coefficient that tracks
the increasing RDS(ON) of the external MOSFET. Further
cost and space are saved by the internal in-rush current-
limiting digital soft-start. The MIC2169B is identical to the
MIC2169A with the exception that the MIC2169B supports
pre-bias loads and has a lower impedance gate-drive
circuit. Internal pre-bias circuit prevents output voltage
drooping and excessive reverse inductor current when
powering up with a pre-bias voltage at the output.
⢠Build-in 2.2⦠drivers to drive two n-channel MOSFETs
⢠Adaptive gate drive increases efficiency
⢠Simple, externally-compensated voltage-mode PWM
control
⢠Short minimum ON time of 30ns allowing very-low duty
cycle
⢠Fast transient response
⢠Adjustable current limit senses high-side N-Channel
MOSFET current
⢠Hiccup mode short-circuit protection
⢠No external current-sense resistor
⢠Internal soft-start current source
⢠Dual function COMP and EN pin allows low-power
shutdown
⢠Available in small-size 10-pin MSOP and 10-pin MSOP
ePad packages
The MIC2169B is available in a 10-pin MSOP and a
thermally-capable 10-pin ePad MSOP package, with a
wide junction operating range of -40°C to +125°C.
All support documentation can be found on Micrelâs web
site at www.micrel.com.
Applications
⢠Point-of-load DC/DC conversion
⢠High-Current Power Supplies
⢠Telecom/Datacom and Networking Power Supplies
⢠Servers and Workstations
⢠Graphic cards and other PC Peripherals
⢠Set-top boxes
⢠LCD power supplies
___________________________________________________________________________________________________________
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 2010
M9999-041210-B
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