參數(shù)資料
型號(hào): TPS40003
廠商: Texas Instruments, Inc.
英文描述: Low Input Voltage Mode Synchronous Buck Controller
中文描述: 低輸入電壓模式同步降壓控制器
文件頁數(shù): 3/20頁
文件大?。?/td> 280K
代理商: TPS40003
TPS40000, TPS40001
TPS40002, TPS40003
TPS40004, TPS40005
SLUS507B JANUARY 2002 REVISED AUGUST 2003
11
www.ti.com
APPLICATION INFORMATION
detailed description
During each switching cycle, a comparator looks at the voltage across the top side MOSFET while it is on. This
comparator is enabled after the SW node reaches a voltage greater than (VDD1.2 V) followed by a 100-ns
blanking time. If the voltage across that MOSFET exceeds a programmable threshold voltage, the
current-switching pulse is terminated and a 3-bit counter is incremented by one count. If, during the switching
cycle, the topside MOSFET voltage does not exceed a preset threshold, then this counter is decremented by
one count. (The counter does not wrap around from 7 to 0 or from 0 to 7). If the counter reaches a full count
of 7, the device declares that a fault condition exists at the output of the converter. In this fault state, HDRV is
turned off and LDRV is turned on and the soft-start capacitor is discharged. The counter is decremented by one
by the soft start capacitor (CSS) discharge. When the soft-start capacitor is fully discharged, the discharging
circuit is turned off and the capacitor is allowed to charge up at the nominal charging rate. When the soft-start
capacitor reaches about 700 mV, it is discharged again and the overcurrent counter is decremented by one
count. The capacitor is charged and discharged, and the counter decremented until the count reaches zero (a
total of six times). When this happens, the outputs are again enabled as the soft-start capacitor generates a
reference ramp for the converter to follow while attempting to restart.
During this soft-start interval (whether or not the controller is attempting to do a fault recovery or starting for the
first time), pulse-by-pulse current limiting is in effect, but overcurrent pulses are not counted to declare a fault
until the soft-start cycle has been completed. It is possible to have a supply attempt to bring up a short circuit
for the duration of the soft start period plus seven switching cycles. Power stage designs should take this into
account if it makes a difference thermally. Figure 3 shows the details of the overcurrent operation.
UDG01145
0V
VTS
Overcurrent
Cycle
Normal
Cycle
Internal PWM
External
Main Drive
Overcurrent
Threshold
Voltage
(+)
VTS
()
Figure 3. Switch Node Waveforms for Synchronous Buck Converter
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TPS40003DGQ 功能描述:電壓模式 PWM 控制器 Low Input Synch Buck Cntrlr RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓?fù)浣Y(jié)構(gòu):Buck 輸出電壓:34 V 輸出電流: 開關(guān)頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel
TPS40003DGQ 制造商:Texas Instruments 功能描述:DC/DC BUCK CONTROLLER SMD 40003
TPS40003DGQG4 功能描述:電壓模式 PWM 控制器 Lo Input Vltg Mode Synch Buck Cntrlr RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓?fù)浣Y(jié)構(gòu):Buck 輸出電壓:34 V 輸出電流: 開關(guān)頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel
TPS40003DGQR 功能描述:電壓模式 PWM 控制器 Lo Input Vltg Mode Synch Buck Cntrlr RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓?fù)浣Y(jié)構(gòu):Buck 輸出電壓:34 V 輸出電流: 開關(guān)頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel
TPS40003DGQRG4 功能描述:電壓模式 PWM 控制器 Lo Input Vltg Mode Synch Buck Cntrlr RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓?fù)浣Y(jié)構(gòu):Buck 輸出電壓:34 V 輸出電流: 開關(guān)頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel