参数资料
型号: MIC2185BQS
厂商: Micrel Inc
文件页数: 8/15页
文件大小: 0K
描述: IC REG CTRLR BST PWM CM 16-QSOP
标准包装: 98
PWM 型: 电流模式
输出数: 1
频率 - 最大: 440kHz
占空比: 95%
电源电压: 2.9 V ~ 14 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 125°C
封装/外壳: 16-SSOP(0.154",3.90mm 宽)
包装: 管件
MIC2185
MOSFET, Q2. Current ?ows through the MOSFET because
its voltage drop is less than diode D1. The MOSFET remains
on until the end of the switching cycle. There is another
non-overlap time delay between the turn-off of the high side
MOSFET and the turn-on of the low side MOSFET at the
beginning of the next switching cycle.
The description of the MIC2185 controller is broken down
into 6 basic functions.
? Control Loop
? PWM Operation
? SKIP Mode Operation
? Current Limit
? MOSFET gate drive
? Reference, Enable & UVLO
? Oscillator & Sync
? Soft Start
V IN
Micrel, Inc.
Control Loop
PWM and SKIP modes of operation
The MIC2185 can operate in either PWM (pulse width modu-
lated) or skip mode. The ef?ciency of the boost converter can
be improved at lower output loads by manually selecting the
skip mode of operation. The potential disadvantage of skip
mode is the variable switching frequency that accompanies
this mode of operation. The occurrence of switching pulses
depends on component values as well as line and load con-
ditions. PWM mode is the best choice of operation at higher
output loads. In skip mode, current through the inductor can
settle to zero, causing voltage ringing across the inductor.
PWM mode has the advantages of lower output ripple volt-
age and higher ef?ciencies at higher output loads. Another
advantage of the synchronous PWM mode of operation is
that the inductor current is always continuous, even at zero
output current. This reduces parasitic ringing that occurs
C DECOUP
V IN A 1
C IN
V IN P
L1
EN/UVLO
7
Bias
V REF
V DD
16
D1
V DD
SKIP
2
Control
On
P GND
OUTP
14
Q2
C OUT
V OUT
OUTN
13
Q1
FREQ/2
15
SYNC
11
SS
3
Osc
Current Reset
Skip Current
Limit Comparator
50mV
P GND
CSH
9
R SENSE
COMP
4
V REF
1.245V
P GND
PGND
12
VREF
8
VDD
10
V REF
V DD
Hysteresis
Comparator
1%
FB
6
R1
R2
S GND
SGND
5
Figure 2. MIC2185 Skip Mode Block Diagram
MIC2185
8
October 2005
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相关代理商/技术参数
参数描述
MIC2185BQS TR 功能描述:IC REG CTRLR BST PWM CM 16-QSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:4,000 系列:- PWM 型:电压模式 输出数:1 频率 - 最大:1.5MHz 占空比:66.7% 电源电压:4.75 V ~ 5.25 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 85°C 封装/外壳:40-VFQFN 裸露焊盘 包装:带卷 (TR)
MIC2185YM 功能描述:DC/DC 开关控制器 SO-16 Low Vin Synchronous Buck PWM Control IC (Lead Free) RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK
MIC2185YM TR 功能描述:DC/DC 开关控制器 SO-16 Low Vin Synchronous Buck PWM Control IC (Lead Free) RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK
MIC2185YQS 功能描述:DC/DC 开关控制器 SO-16 Low Vin Synchronous Buck PWM Control IC (Lead Free) RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK
MIC2185YQS TR 功能描述:DC/DC 开关控制器 SO-16 Low Vin Synchronous Buck PWM Control IC (Lead Free) RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK