參數(shù)資料
型號: TPS40055MPWPREPG4
廠商: TEXAS INSTRUMENTS INC
元件分類: 穩(wěn)壓器
英文描述: SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO16
封裝: PLASTIC, HTSSOP-16
文件頁數(shù): 7/35頁
文件大小: 2348K
代理商: TPS40055MPWPREPG4
www.ti.com
SGLS310B – JULY 2005 – REVISED OCTOBER 2010
(16)
where:
ISINK is the current into the ILIM pin and is 8.5 A, minimum
IOC is the overcurrent setpoint which is the dc output current plus one-half of the peak inductor current
VOS is the overcurrent comparator offset and is –20 mV, maximum
SYNCHRONIZING TO AN EXTERNAL SUPPLY
The TPS40055 can be synchronized to an external clock through the SYNC pin. Synchronization occurs on the
falling edge of the SYNC signal. The synchronization frequency should be in the range of 20% to 30% higher
than its programmed free-run frequency. The clock frequency at the SYNC pin replaces the master clock
generated by the oscillator circuit. Pulling the SYNC pin low programs the TPS40055 to freely run at the
frequency programmed by RT.
The higher synchronization must be factored in when programming the PWM ramp generator circuit. If the PWM
ramp is interrupted by the SYNC pulse, a UVLO condition is declared and the PWM becomes disabled. Typically
this is of concern under low-line conditions only. In any case, RKFF needs to be adjusted for the higher switching
frequency. In order to specify the correct value for RKFF at the synchronizing frequency, calculate a dummy value
for RT that would cause the oscillator to run at the synchronizing frequency. Do not use this value of RT in the
design.
(17)
Use the value of RT(dummy) to calculate the value for RKFF.
(18)
This value of RKFF ensures that UVLO is not engaged when operating at the synchronization frequency.
RT(dummy) is in k
Loop Compensation
Voltage-mode buck-type converters are typically compensated using Type III networks. Since the TPS40055
uses voltage feedforward control, the gain of the PWM modulator with voltage feedforward circuit must be
included. The modulator gain is described in Figure 10, with VIN being the minimum input voltage required to
cause the ramp excursion to cover the entire switching period as described in Equation 19.
(19)
Duty cycle (D) varies from 0 to 1 as the control voltage (VC) varies from the minimum ramp voltage to the
maximum ramp voltage (VS). Also, for a synchronous buck converter, D = VO / VIN. To get the control voltage to
output voltage modulator gain in terms of the input voltage and ramp voltage:
(20)
Copyright 2005–2010, Texas Instruments Incorporated
15
Product Folder Link(s): TPS40055-EP
相關(guān)PDF資料
PDF描述
TPS40055QPWPRQ1 SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO16
TPS40054QPWPRQ1 SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO16
TPS40070PWPRG4 2 A SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO16
TPS40071PWPR 2 A SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO16
TPS40070PWPR 2 A SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO16
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TPS40055PWP 功能描述:DC/DC 開關(guān)控制器 Wide Input Sync Buck Cntrlr source/sink RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
TPS40055PWPG4 功能描述:DC/DC 開關(guān)控制器 Wide Input Sync Buck Cntrlr source/sink RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
TPS40055PWPR 功能描述:DC/DC 開關(guān)控制器 Wide Input Sync Buck Cntrlr source/sink RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
TPS40055PWPRG4 功能描述:DC/DC 開關(guān)控制器 Wide Input Sync Buck Cntrlr source/sink RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
TPS40056 制造商:TI 制造商全稱:Texas Instruments 功能描述:WIDE-INPUT SYNCHRONOUS, TRACKING BUCK CONTROLLER