收藏本站
LMZ10505EXT
www.ti.com
SNVS669G – JUNE 2010 – REVISED OCTOBER 2013
where V FB is the internal reference voltage (nominally 0.8V), I SS is the soft-start charging current (nominally 2 μA)
and C SS is the external soft-start capacitance.
Thus, the required soft-start capacitor per unit output voltage startup time is given by
C SS = 2.5 nF / ms
(21)
For example, a 4 ms soft-start time will yield a 10 nF capacitance. The minimum soft-start capacitance is 680 pF.
TRACKING
The LMZ10505EXT can track the output of a master power supply during soft-start by connecting a resistor
divider to the SS pin. In this way, the output voltage slew rate of the LMZ10505EXT will be controlled by a
master supply for loads that require precise sequencing. When the tracking function is used, a small value soft-
start capacitor should be connected to the SS pin to alleviate output voltage overshoot when recovering from a
current limit fault.
Master Power
Supply
V OUT1
V IN
VIN
VOUT
V OUT2
C in1
V SS
R trkt
EN
SS
LMZ10505EXT
C O1
R trkb
GND
TRACKING - EQUAL SOFT-START TIME
One way to use the tracking feature is to design the tracking resistor divider so that the master supply output
voltage, V OUT1 , and the LMZ10505EXT output voltage, V OUT2 , both rise together and reach their target values at
the same time. This is termed ratiometric startup. For this case, the equation governing the values of tracking
divider resistors R trkb and R trkt is given by
R trkb =
R trkt
V OUT1 -1.0V
(22)
The above equation includes an offset voltage, of 200 mV, to ensure that the final value of the SS pin voltage
exceeds the reference voltage of the LMZ10505EXT. This offset will cause the LMZ10505EXT output voltage to
reach regulation slightly before the master supply. A value of 33 k ? 1% is recommended for R trkt as a
compromise between high precision and low quiescent current through the divider while minimizing the effect of
the 2 μA soft-start current source.
For example, if the master supply voltage V OUT1 is 3.3V and the LMZ10505EXT output voltage was 1.8V, then
the value of R trkb needed to give the two supplies identical soft-start times would be 14.3 k ? . A timing diagram for
this example, the equal soft-start time case, is shown below.
RATIOMETRIC STARTUP
V OUT1
V OUT2
EN
TIME
Copyright ? 2010–2013, Texas Instruments Incorporated
Product Folder Links: LMZ10505EXT
Submit Documentation Feedback
15
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
LMZ14201TZE-ADJ/NOPB IC BUCK SYNC ADJ 1A TO-PMOD-7
LMZ14203EXTTZE/NOPB IC BUCK SYNC ADJ 3A TO-PMOD-7
LNC2W153MSEJ CAP ALUM 15000UF 450V 20% SCREW
LNK2H822MSEJ CAP ALUM 8200UF 500V 20% SCREW
LNT2H103MSEJ CAP ALUM 10000UF 500V 20% SCREW
LNX2J562MSEK CAP ALUM 5600UF 630V 20% SCREW
LNY2W153MSEJ CAP ALUM 15000UF 450V 20% SCREW
LP122M250H9P3 CAP ALUM 1200UF 250V 20% SNAP
相关代理商/技术参数
LMZ10505EXTTZX 制造商:TI 制造商全称:Texas Instruments 功能描述:5A SIMPLE SWITCHER?? Power Module with 5.5V Maximum Input Voltage for Military and Rugged Applications
LMZ10505EXTTZX/NOPB 功能描述:直流/直流开关转换器 RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
LMZ10505TZ-ADJ 制造商:NSC 制造商全称:National Semiconductor 功能描述:5A SIMPLE SWITCHER? Power Module with 5.5V Maximum Input Voltage
LMZ10505TZ-ADJ/NOPB 功能描述:直流/直流开关转换器 5V,5A PWR MODULE RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
LMZ10505TZADJNOPB 制造商:Texas Instruments 功能描述:Module DC-DC 1-OUT 0.8V to 5V 5A 7-Pin TO-PMOD EP
LMZ10505TZE-ADJ 制造商:NSC 制造商全称:National Semiconductor 功能描述:5A SIMPLE SWITCHER? Power Module with 5.5V Maximum Input Voltage
LMZ10505TZE-ADJ/NOPB 功能描述:直流/直流开关转换器 RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
LMZ10505TZX-ADJ 制造商:NSC 制造商全称:National Semiconductor 功能描述:5A SIMPLE SWITCHER? Power Module with 5.5V Maximum Input Voltage