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MIC2182_04 Datasheet, PDF (1/28 Pages) Micrel Semiconductor – High-Efficiency Synchronous Buck Controller | |||
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MIC2182
Micrel
MIC2182
High-Efficiency Synchronous Buck Controller
General Description
Micrelâs MIC2182 is a synchronous buck (step-down) switch-
ing regulator controller. An all N-channel synchronous archi-
tecture and powerful output drivers allow up to a 20A output
current capabilty. The PWM and skip-mode control scheme
allows efficiency to exceed 95% over a wide range of load
current, making it ideal for battery powered applications, as
well as high current distributed power supplies.
The MIC2182 operates from a 4.5V to 32V input and can
operate with a maximum duty cycle of 86% for use in low-
dropout conditions. It also features a shutdown mode that
reduces quiescent current to 0.1µA.
The MIC2182 achieves high efficiency over a wide output
current range by automatically switching between PWM and
skip mode. Skip-mode operation enables the converter to
maintain high efficiency at light loads by turning off circuitry
pertaining to PWM operation, reducing the no-load supply
current from 1.6mA to 600µA. The operating mode is inter-
nally selected according to the output load conditions. Skip
mode can be defeated by pulling the PWM pin low which
reduces noise and RF interference.
The MIC2182 is available in a 16-pin SOP (small-outline
package) and SSOP (shrink small-outline package) with an
operating range from â40°C to +85°C.
Features
⢠4.5V to 32V Input voltage range
⢠1.25V to 6V Output voltage range
⢠95% efficiency
⢠300kHz oscillator frequency
⢠Current sense blanking
⢠5⦠impedance MOSFET Drivers
⢠Drives N-channel MOSFETs
⢠600µA typical quiescent current (skip-mode)
⢠Logic controlled micropower shutdown (IQ < 0.1µA)
⢠Current-mode control
⢠Cycle-by-cycle current limiting
⢠Built-in undervoltage protection
⢠Adjustable undervoltage lockout
⢠Easily synchronizable
⢠Precision 1.245V reference output
⢠0.6% total regulation
⢠16-pin SOP and SSOP packages
⢠Frequency foldback overcurrent protection
⢠Sustained short-circuit protection at any input voltage
⢠20A output current capability
Applications
⢠DC power distribution systems
⢠Notebook and subnotebook computers
⢠PDAs and mobile communicators
⢠Wireless modems
⢠Battery-operated equipment
Typical Application
VIN
4.5V to 30V*
R7
100k
GND
C3
0.1µF
C2
2.2nF
MIC2182-3.3BSM
D2
10 VIN
VDD 11 SD103BWS
C5
0.1µF
BST 14
C6
6 EN/UVLO HSD 16
0.1µF
2 PWM
C4
1nF
VSW 15
LSD 13
1 SS
PGND 12
C11
22uf
35V
C9
x2
4.7µF
16V
Q2*
Si4884
L1
10µH
Q1*
Si4884
D1
B140
R2
0.02â¦
3 COMP
R1
2k
5 SYNC
CSH 8
VOUT 9
VREF 7
SGND
4
C13, 1nF
* 30V maximum input voltage limit is due
to standard 30V MOSFET selection.
C1
0.1µF See âApplication Informationâ section for
5V to 3.3V/10A and other circuits.
VOUT
3.3V/4A
C7
220uf
10V Ã2
GND
4.5Vâ30V* to 3.3V/4A Converter
Micrel, Inc. ⢠1849 Fortune Drive ⢠San Jose, CA 95131 ⢠USA ⢠tel + 1 (408) 944-0800 ⢠fax + 1 (408) 474-1000 ⢠http://www.micrel.com
April 22, 2004
1
M9999-042204
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