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MIC2169A Datasheet, PDF (1/17 Pages) Micrel Semiconductor – 500kHz PWM Synchronous Buck Control IC | |||
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MIC2169A
500kHz PWM Synchronous Buck Control IC
General Description
The MIC2169A is a high-efï¬ciency, simple to use 500kHz
PWM synchronous buck control IC housed in a small MSOP-
10 package. The MIC2169A allows compact DC/DC solutions
with a minimal external component count and cost.
The MIC2169A 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 efï¬ciencies over
95% across a wide load range.
The MIC2169A 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 coefï¬cient 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 MIC2169A is available in a 10-pin MSOP package, with
a wide junction operating range of â40°C to +125°C.
All support documentation can be found on Micrelâs web site
at www.micrel.com.
Features
⢠3V to 14.5V input voltage range
⢠Adjustable output voltage down to 0.8V
⢠Up to 95% efï¬ciency
⢠500kHz PWM operation
⢠Adjustable current limit senses high-side N-Channel
MOSFET current
⢠No external current-sense resistor
⢠Adaptive gate drive increases efï¬ciency
⢠Ultra-fast response with hysteretic transient recovery
mode
⢠Overvoltage protection protects the load in fault
conditions
⢠Dual mode current limit speeds up recovery time
⢠Hiccup mode short-circuit protection
⢠Internal soft-start
⢠Dual function COMP and EN pin allows low-power shut-
down
⢠Small size MSOP 10-lead package
Applications
⢠Point-of-load DC/DC conversion
⢠Set-top boxes
⢠Graphic cards
⢠LCD power supplies
⢠Telecom power supplies
⢠Networking power supplies
⢠Cable modems and routers
Typical Application
VIN = 5V
100ïF
5ï
150pF
100nF
4kï
0.1µF
SD103BWS
4.7ïF
0.1ïF
0.1ïF
VDD
BST
CS
VIN
HSD
MIC2169A
VSW
2ï
COMP/EN
LSD
GND FB
1kï
IRF7821
2.5ïH
IRF7821
1.4ï
1000pF
3.3V
10kï
3.24kï
150ïF x 2
MIC2169A Adjustable Output 500kHz Converter
100
95
90
85
80
75
70
65
60
55
50 0
MIC2169A Efficiency
VIN = 5V
VOUT = 3.3V
2 4 6 8 10 12 14 16
ILOAD (A)
Micrel, Inc. ⢠2180 Fortune Drive ⢠San Jose, CA 95131 ⢠USA ⢠tel + 1 (408) 944-0800 ⢠fax + 1 (408) 474-1000 ⢠http://www.micrel.com
June 2005
1
M9999-111803
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