參數(shù)資料
型號(hào): MIC2178
廠商: Micrel Semiconductor,Inc.
英文描述: 2.5A Synchronous Buck Regulator
中文描述: 包2.5a同步降壓穩(wěn)壓器
文件頁(yè)數(shù): 1/16頁(yè)
文件大?。?/td> 170K
代理商: MIC2178
June 1998
1
MIC2178
MIC2178
Micrel
MIC2178
2.5A Synchronous Buck Regulator
General Description
The Micrel MIC2178 is a 200kHz synchronous buck (step-
down) switching regulator designed for high-efficiency, bat-
tery-powered applications.
The MIC2178 operates from a 4.5V to 16.5V input and
features internal power MOSFETs that can supply up to 2.5A
output
current. It can operate with a maximum duty cycle of
100% for use in low-dropout conditions. It also features a
shutdown mode that reduces quiescent current to less than
5
μ
A.
The MIC2178 achieves high efficiency over a wide output
current range by operating in either PWM or skip mode. The
operating mode is externally selected, typically by an intelli-
gent system, which chooses the appropriate mode according
to operating conditions, efficiency, and noise requirements.
The switching frequency is preset to 200kHz and can be
synchronized to an external clock signal of up to 300kHz.
The MIC2178 uses current-mode control with internal current
sensing. Current-mode control provides superior line regula-
tion and makes the regulator control loop easy to compen-
sate. The output is protected with pulse-by-pulse current
limiting and thermal shutdown. Undervoltage lockout turns
the output off when the input voltage is less than 4.5V.
The MIC2178 and is packaged in a 20-lead wide power SOIC
package with an operating temperature range of –40
°
C to
+85
°
C.
See the MIC2177 for automatic selection of PWM or skip-
mode operation.
Typical Application
Features
4.5V to 16.5V input voltage range
Dual-mode operation for high efficiency (up to 96%)
PWM mode for > 200mA load current
Skip mode for < 200mA load current
100m
internal power MOSFETs at 12V input
200kHz preset switching frequency
Low quiescent current
1.0mA in PWM mode
600
μ
A in skip mode
< 5
μ
A in shutdown mode
Current-mode control
Simplified loop compensation
Superior line regulation
100% duty cycle for low dropout operation
Current limit
Thermal shutdown
Undervoltage lockout
Applications
High-efficiency, battery-powered supplies
Buck (step-down) dc-to-dc converters
Palmtop computers
Laptop computers
Cellular telephones
Hand-held instruments
Battery Chargers
BIAS
SGND
PWRGD
COMP
PGND
FB
SW
VIN
L1
33μH
C6
10nF
C5
0.01μF
MIC
2178-5.0
PWM
SYNC
EN
R1
20k
R2
15k
U1
20
11
10
18
13
14–17
19
12
4–7
3,8
1,2,9
D1
MBRS140
OOUTPUT LOW
C4
220μF
10V
V
5V/2.5A
C3
220μF
10V
V
6V to 16.5V
C1
22μF
35V
C2
22μF
35V
SKIP MODE
70
75
80
85
90
95
100
10
100
1000 2500
E
OUTPUT CURRENT (mA)
5V Output
Efficiency
V
IN
= 6V
SKIP
PWM
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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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MIC2178_05 制造商:MICREL 制造商全稱:Micrel Semiconductor 功能描述:2.5A Synchronous Buck Regulator
MIC2178-3.3BWM 功能描述:直流/直流開關(guān)調(diào)節(jié)器 2.5A 200kHz Synchronous Switcher RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5
MIC2178-3.3BWM TR 功能描述:直流/直流開關(guān)調(diào)節(jié)器 2.5A 200kHz Synchronous Switcher RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5
MIC2178-3.3YWM 功能描述:直流/直流開關(guān)調(diào)節(jié)器 2.5A 200kHz Synchronous Switcher RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5
MIC2178-3.3YWM TR 功能描述:直流/直流開關(guān)調(diào)節(jié)器 2.5A 200kHz Synchronous Switcher RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5