- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄69508 > TPS40040DRBT (TEXAS INSTRUMENTS INC) 7.2 A SWITCHING CONTROLLER, 350 kHz SWITCHING FREQ-MAX, PDSO8 PDF資料下載
參數(shù)資料
| 型號(hào)： | TPS40040DRBT |
| 廠商： | TEXAS INSTRUMENTS INC |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | 7.2 A SWITCHING CONTROLLER, 350 kHz SWITCHING FREQ-MAX, PDSO8 |
| 封裝： | 3 X 3 MM, PLASTIC, SON-8 |
| 文件頁數(shù)： | 7/38頁 |
| 文件大?。?/td> | 741K |
| 代理商： | TPS40040DRBT |
第1頁第2頁第3頁第4頁第5頁第6頁當(dāng)前第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁
www.ti.com
Bootstrap for N-Channel MOSFET Drive
Bootstrap Capacitor Series Resistor
External Schottky Diode for Low Input Voltage
VDD Bypass and Filtering
SLUS700D – MARCH 2006 – REVISED DECEMBER 2007
The PWM duty cycle is limited to a maximum of 95%, allowing the bootstrap capacitor to charge during every
cycle. During each PWM OFF period, the voltage on VDD charges the bootstrap capacitor. When the PWM
switch is next commanded to turn ON, the voltage used to drive the MOSFET is derived from the voltage on this
capacitor. Since this is a charge transfer circuit, the value of the bootstrap capacitor must be sized such that the
energy stored in the capacitor on a per cycle basis is greater then the gate charge requirement of the MOSFET
being used. See the Design Example section for details.
Since resistors should not be placed in series with the high-side gate, it may be necessary to place a small 1-
to 3-
resistor in series with the bootstrap capacitor to control the turn-on of the main switching MOSFET and
reduce the dV/dt rate of rise of the switch node voltage. A resistor placed between the BOOT pin and the
bootstrap capacitor increases the series resistance during the turn-on of the high-side MOSFET, and has no
effect during the high-side MOSFET’s turn-off period. This prevents the TPS40040/1 from sensing the upper
switch MOSFET’s turn-off too early and reducing the upper switch MOSFET turn-off to the SR MOSFET turn-on
delay timing too far.
DESIGN
To reduce EMI, place a small 1-
to 3- resistor in series with the boost
HINT:
capacitor to control the turn-on of the main switching FET.
The TPS40040/1 uses an internal P-channel MOSFET switch between VDD and BOOT to charge the bootstrap
capacitor during synchronous rectifier conduction time. At low input voltages, a MOSFET can not be turned on
hard enough to rapidly replenish the charge required to turn on an (high gate charge) external high-side
MOSFET. For this situation, an external Schottky diode between the VDD and BOOT pins may be added. While
the diode carries very small average current (QG x FSW) it may be required to carry several hundred mA of peak
surge current. The diode should be rated for at least 500 mA of surge current. For higher input voltage
applications, if a resistor is used in series with the boost capacitor, connect the diode to the junction of the
resistor and capacitor to remove the added resistance from the capacitor’s charge path.
For low input voltages, and a high gate charge upper switch MOSFET, a small
DESIGN
Schottky diode should be placed from VDD to BOOT. Do not use a resistor in
HINT:
series with the boost capacitor.
To prevent switching noise from being injected into the TPS40040/1 control circuitry, a ceramic capacitor (1
F
minimum) must be placed as close to the VDD pin and GND pad as possible.
Copyright 2006–2007, Texas Instruments Incorporated
15
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| TPS40041DRBRG4 | 7.2 A SWITCHING CONTROLLER, 700 kHz SWITCHING FREQ-MAX, PDSO8 |
| TPS40050QPWPRQ1 | SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO16 |
| TPS40051QPWPRQ1 | SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO16 |
| TPS40051PWP | 0.2 A SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO16 |
| TPS40050PWP | 0.2 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 |
|---|---|
| TPS40040DRBT | 制造商:Texas Instruments 功能描述:Peak Reflow Compatible (260 C):Yes |
| TPS40040DRBTG4 | 功能描述:DC/DC 開關(guān)控制器 Lo Vin Synch Buck DC/DC Cntrlr 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 |
| TPS40040EVM-001 | 功能描述:電源管理IC開發(fā)工具 10A Synch Buck Eval Mod RoHS:否 制造商:Maxim Integrated 產(chǎn)品:Evaluation Kits 類型:Battery Management 工具用于評(píng)估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V |
| TPS40041 | 制造商:TI 制造商全稱:Texas Instruments 功能描述:LOW PIN COUNT, LOW VIN (2.5 V TO 5.5 V) SYNCHRONOUS BUCK DC-TO-DC CONTROLLER WITH ENABLE |
| TPS40041DRBR | 功能描述:DC/DC 開關(guān)控制器 Low Vin Synch Buck DC/DC Controller 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 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。