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器件描述：Low Voltage Buck PWM Control IC Final Information
器件厂商：MICREL [Micrel Semiconductor]
厂商主页：http://www.micrel.com/
文件大小：75.86KB
文件页数：12
PDF阅读：MIC2184.pdf (点击阅读器件资料)
摘要：
December 10, 2001 1 MIC2184
MIC2184 Micrel
MIC2184
Low Voltage Buck PWM Control IC
Final Information
General Description
Micrel’s MIC2184 is a high efficiency PWM buck control IC.
With its wide input voltage range of 2.9V to 14V, the MIC2184
can be used to efficiently step voltages down in 1- or 2-cell Li
Ion battery powered applications, as well as in fixed 3.3V, 5V,
or 12V systems.
Efficiencies over 90% are achievable over a wide range of
load conditions with the MIC2184’s PWM control scheme.
The operating frequency can be divided by two by raising the
FREQ/2 pin to V
DD
. This allows the user to optimize efficiency
versus board space. It also allows the MIC2184 to be exter-
nally synchronized to frequencies below its nominal 400KHz.
The MIC2184 features an oscillator output, FreqOut, which
can be used to implement a simple charge pump in low
voltage applications. The output of the charge pump can be
fed into the gate drive power circuitry via the V
IN
P pin,
allowing enhanced gate drive, hence higher efficiencies,
despite low input voltages.
MIC2184 features a 1?A shutdown mode, and a program-
mable undervoltage lockout, making it well suited for portable
applications.
The MIC2184 is available in 16 pin SOP and QSOP package
options with a junction temperture range range from –40°C
to +125°C.
Typical Application
FreqOut
VINA
EN/UVLO
V
OUT
2.5V @5A
FREQ/2
VDD
COMP
SS
VREF
SYNC SGND
MIC2184
VINP
CSH
CSL
OUTP
PGND
FB
V
IN
= 3.3V
1
7
2
16
10
4
3
13
11 5
16
9
8
14
12
6
120?F (x2)
6.3V
15m?
Q3
Si9803DY(x2)
4.7?H
220?F(x2)
6.3V
Adjustable Output Buck Converter
Features
? Input voltage range: 2.9V to 14V
? >90% efficiency
? Oscillator frequency of 400kHz
? Frequency divide-by-two pin
? Frequency sync to 600kHz
? FrequOut oscillator output allows simple charge pump
implementation in low voltage systems
? 1.245V reference output
? Front edge blanking
?5? output driver
? Soft start
? PWM current mode control
?1?A shutdown current
? Cycle-by-cycle current limiting
? Frequency foldback short circuit protection
? Adjustable under-voltage lockout
? 16 pin narrow-body SOIC and QSOP package options
Applications
? 3.3V to 2.5V/1.8V/1.5V conversion
? DC power distribution systems
? Wireless Modems
? ADSL line cards
? 1-and 2-cell Li Ion battery operated equipment
? Satellite Phones
Micrel, Inc. ? 1849 Fortune Drive ? San Jose, CA 95131 ? USA ? tel + 1 (408) 944-0800 ? fax + 1 (408) 944-0970 ? http://www.micrel.com
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012345
EFFICIENCY (%)
OUTPUT CURRENT (A)
MIC2184 EFFICIENCY
V
IN
= 3.3V
V
OUT
= 2.5V
f
S
= 200kHz
相关器件：MIC2184BM MIC2184BQS
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