参数资料
型号: MIC2044-2BTS TR
厂商: Micrel Inc
文件页数: 11/15页
文件大小: 0K
描述: IC DISTRIBUTION SW SGL 16-TSSOP
标准包装: 2,500
类型: 高端开关
输出数: 1
Rds(开): 30 毫欧
内部开关:
电流限制: 可调
输入电压: 0.8 V ~ 5.5 V
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 16-TSSOP(0.173",4.40mm 宽)
供应商设备封装: 16-TSSOP
包装: 带卷 (TR)
其它名称: MIC2044-2BTSTR
MIC2044-2BTSTR-ND
MIC2044/2045
Functional Description
The MIC2044 and MIC2045 are high-side N-Channel switches
equipped with programmable current limit up to 6A for use in
general purpose power distribution applications. The switches,
available with active-high or active-low enable inputs, provide
output slew-rate control and circuit protection via thermal
shutdown and an optional output latch during overcurrent
conditions.
Input and Output
VBIAS supplies power to the internal circuitry of the switch
and must be present for the switch to operate. VIN is con-
nected to the drain of the output MOSFET and sources power
to the switched load. VIN must be less than or equal to VBIAS.
VOUT is the source terminal of the output MOSFET and
attaches to the load. In a typical circuit, current flows from VIN
to VOUT toward the load. If VOUT is greater than VIN, current
will flow from VOUT to VIN since the switch is bi-directional
Micrel
Programmable Current Limit
The MIC2044/45 is designed to prevent damage to the
external load by limiting the maximum amount of current it
can draw. The current limit is programmed by an external
resistor (R SET ) connected from ILIM (Pin 6) to ground and
becomes active when the output voltage is at least 200mV
below the voltage at the input to the device. The limiting
current value is defined by the current limit factor (CLF)
divided by R SET , and the MIC2044/45 will limit from 1A to 6A
with a set point accuracy of ± 21%. In programming the
nominal current limit, the value of R SET is determined using
the following equation:
CLF ( 380A × ? )
R SET = = (1)
I LIMIT I LIMIT
And given the ± 21% tolerance of the current limit factor (CLF),
the external resistor is bound by:
when the device is enabled. When disabled (OFF), the switch
50 ? ≤ R SET ≤ 460 ?
(2)
will block current flow from either direction.
Enable Input
Enable, the ON/OFF control for the output switch, is a digital
input available as an active-high (–1) or active-low (–2)
signal. The EN pin, referenced to approximately 0.5 × VBIAS,
must be driven to a clearly defined logic high or logic low.
Failure to observe this requirement, or allowing EN to float,
will cause the MIC2044/45 to exhibit unpredictable behavior.
EN should not be allowed to go negative with respect to
ground, nor allowed to exceed VBIAS. Failure to adhere to
these conditions may result in damage to the device.
Undervoltage Lockout
When the switch is enabled, undervoltage lockout (UVLO)
monitors the input voltage, V IN , and prevents the output
MOSFET from turning on until V IN exceeds a predetermined
level, nominally set at 1.45V. The UVLO threshold is adjust-
able and can be varied by applying an external resistor divider
to the UVLOIN pin from VIN to GND. The resistive divider
network is required when the input voltage is below 1.5V. The
UVLO threshold is internally preset to 1.45V if the UVLOIN
pin is left open. See “Applications Information.”
Current Limit
The graphs below (Figure 3) display the current limit factor
characteristic over the full temperature range at the indicated
voltage. These curves can be used as a point of reference in
determining the maximum variation in the device’s current
limit over the full temperature range. For example: With V IN
= V BIAS = 3.0V and a nominal 4A current limit (R SET = 95 ? ),
the low and high current limit settings for the MIC2044/45
would be 3.15A and 4.85A, respectively, as shown on the 3V
graph using the 95 ? reference point.
When current limiting occurs, the MIC2044 and MIC2045
respond differently. Upon first reaching the limiting current
both devices restrict current flow, allowing the load voltage to
drop below V IN . If the V IN to V OUT differential voltage exceeds
200mV, then a fault condition is declared and the fault delay
timer is started. If the fault condition persists longer than the
delay period, typically 32ms, then the /FAULT output asserts
low. At this point, the MIC2044 will continue to supply current
to the load at the limiting value (I LIMIT ), whereas the MIC2045
will latch off its output.
Current Limit
8
7
6
5
4
3
2
1
0
vs. R SET
–40 ° C to +85 ° C
V IN = V BIAS = 3V, 5V
CLF (HI)
CLF (LO)
0 50 100 150 200 250 300 350 400 450
R SET ( ? )
8
7
6
5
4
3
2
1
0
vs. R SET
–40 ° C to +85 ° C
V IN = V BIAS = 1.6V
CLF (HI)
CLF (LO)
0 50 100 150 200 250 300 350 400 450
R SET ( ? )
Figure 3. Current Limit Factor
January 2005
11
MIC2044/2045
相关PDF资料
PDF描述
222A152-100-0 BOOT MOLDED
382LX473M050B062VS CAP ALUM 47000UF 50V 20% SNAP
MIC2045-1BTS IC DISTRIBUTION SW SGL 16-TSSOP
0982660108 CBL 10POS 0.5MM JMPR TYPE D 7"
LAR2W221MELA40 CAP ALUM 220UF 450V 20% SNAP
相关代理商/技术参数
参数描述
MIC2044-2YTS 功能描述:电源开关 IC - USB 22 mohm Low Voltage Switch - Lead Free RoHS:否 制造商:Micrel 电源电压-最小:2.7 V 电源电压-最大:5.5 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:SOIC-8 封装:Tube
MIC2044-2YTS TR 功能描述:电源开关 IC - USB 23 mohm Low Voltage Switch - Lead Free RoHS:否 制造商:Micrel 电源电压-最小:2.7 V 电源电压-最大:5.5 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:SOIC-8 封装:Tube
MIC2045 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:Single Channel, High Current, Low Voltage, Protected Power Distribution Switch
MIC2045-1BTS 功能描述:IC DISTRIBUTION SW SGL 16-TSSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 电源分配开关 系列:- 特色产品:XRP252 Switches 标准包装:1 系列:- 类型:高端开关 输出数:2 Rds(开):140 毫欧 内部开关:是 电流限制:1.15A 输入电压:1.75 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:10-WFDFN 裸露焊盘 供应商设备封装:10-TDFN(3x3) 包装:Digi-Reel® 其它名称:1016-1691-6
MIC2045-1BTS TR 功能描述:IC DISTRIBUTION SW SGL 16-TSSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 电源分配开关 系列:- 特色产品:XRP252 Switches 标准包装:1 系列:- 类型:高端开关 输出数:2 Rds(开):140 毫欧 内部开关:是 电流限制:1.15A 输入电压:1.75 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:10-WFDFN 裸露焊盘 供应商设备封装:10-TDFN(3x3) 包装:Digi-Reel® 其它名称:1016-1691-6