- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄98283 > TPS54418RTER (TEXAS INSTRUMENTS INC) 6.4 A SWITCHING REGULATOR, 2000 kHz SWITCHING FREQ-MAX, PQCC16 PDF資料下載
參數(shù)資料
| 型號： | TPS54418RTER |
| 廠商： | TEXAS INSTRUMENTS INC |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | 6.4 A SWITCHING REGULATOR, 2000 kHz SWITCHING FREQ-MAX, PQCC16 |
| 封裝： | 3 X 3 MM, GREEN, PLASTIC, WQFN-16 |
| 文件頁數(shù)： | 6/35頁 |
| 文件大?。?/td> | 1356K |
| 代理商： | TPS54418RTER |
第1頁第2頁第3頁第4頁第5頁當前第6頁第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
W
1.0793
311890
RT (k ) =
Fsw(kHz)
0.9393
133870
Fsw(kHz)
RT(k )
=
W
SLVS946A – MAY 2009 – REVISED MAY 2010
www.ti.com
CONSTANT SWITCHING FREQUENCY and TIMING RESISTOR (RT/CLK Pin)
The switching frequency of the TPS54418 is adjustable over a wide range from 200 kHz to 2000 kHz by placing
a maximum of 1000k
and minimum of 85 k, respectively, on the RT/CLK pin. An internal amplifier holds this
pin at a fixed voltage when using an external resistor to ground to set the switching frequency. The RT/CLK is
typically 0.5 V. To determine the timing resistance for a given switching frequency, use the curve in Figures TBD
and TBD, or Equation 5.
(5)
(6)
To reduce the solution size one would typically set the switching frequency as high as possible, but tradeoffs of
the efficiency, maximum input voltage and minimum controllable on time should be considered.
The minimum controllable on time is typically 60 ns at full current load and 110 ns at no load, and limits the
maximum operating input voltage or output voltage.
OVERCURRENT PROTECTION
The TPS54418 implements a cycle by cycle current limit. During each switching cycle the high side switch
current is compared to the voltage on the COMP pin. When the instantaneous switch current intersects the
COMP voltage, the high side switch is turned off. During overcurrent conditions that pull the output voltage low,
the error amplifier responds by driving the COMP pin high, increasing the switch current. The error amplifier
output is clamped internally. This clamp functions as a switch current limit.
FREQUENCY SHIFT
To operate at high switching frequencies and provide protection during overcurrent conditions, the TPS54418
implements a frequency shift. If frequency shift was not implemented, during an overcurrent condition the low
side MOSFET may not be turned off long enough to reduce the current in the inductor, causing a current
runaway. With frequency shift, during an overcurrent condition the switching frequency is reduced from 100%,
then 75%, then 50%, then 25% as the voltage decreases from 0.8 to 0 volts on VSENSE pin to allow the low
side MOSFET to be off long enough to decrease the current in the inductor. During start-up, the switching
frequency increases as the voltage on VSENSE increases from 0 to 0.8 volts. See Figure 7 for details.
REVERSE OVERCURRENT PROTECTION
The TPS54418 implements low side current protection by detecting the voltage across the low side MOSFET.
When the converter sinks current through its low side FET, the control circuit turns off the low side MOSFET if
the reverse current is more than 1.3 A. By implementing this additional protection scheme, the converter is able
to protect itself from excessive current during power cycling and start-up into pre-biased outputs.
SYNCHRONIZE USING THE RT/CLK PIN
The RT/CLK pin is used to synchronize the converter to an external system clock. See Figure 28. To implement
the synchronization feature in a system, connect a square wave to the RT/CLK pin with an on time of at least
75ns. If the pin is pulled above the PLL upper threshold, a mode change occurs and the pin becomes a
synchronization input. The internal amplifier is disabled and the pin is a high impedance clock input to the
internal PLL. If clocking edges stop, the internal amplifier is re-enabled and the mode returns to the frequency set
by the resistor. The square wave amplitude at this pin must transition lower than 0.6 V and higher than 1.6 V
typically. The synchronization frequency range is 300 kHz to 2000 kHz. The rising edge of the PH is
synchronized to the falling edge of RT/CLK pin.
14
Copyright 2009–2010, Texas Instruments Incorporated
Product Folder Link(s): TPS54418
相關PDF資料 |
PDF描述 |
|---|---|
| TPS54426PWP | 7.5 A SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO14 |
| TPS54429PWP | 0.01 A SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO14 |
| TPS5450MDDAREP | 11.7 A SWITCHING REGULATOR, 600 kHz SWITCHING FREQ-MAX, PDSO8 |
| TPS54519RTER | 8 A SWITCHING REGULATOR, 2000 kHz SWITCHING FREQ-MAX, PQCC16 |
| TPS54612MPWPREP | 12 A SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO28 |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| TPS54418RTERG4 | 制造商:Texas Instruments 功能描述: |
| TPS54418RTET | 功能描述:直流/直流開關調節(jié)器 2.95-6Vin 4A 2MHz Synch St Down RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5 |
| TPS54424RNVT | 功能描述:4.5V TO 17V INPUT, CURRENT MODE, 制造商:texas instruments 系列:SWIFT?? 包裝:剪切帶（CT） 零件狀態(tài):在售 功能:降壓 輸出配置:正 拓撲:降壓 輸出類型:可調式 輸出數(shù):1 電壓 - 輸入（最小值）:4.5V 電壓 - 輸入（最大值）:17V 電壓 - 輸出（最小值/固定）:0.6V 電壓 - 輸出（最大值）:12V 電流 - 輸出:4A 頻率 - 開關:200kHz ~ 1.6MHz 同步整流器:是 工作溫度:-40°C ~ 150°C（TJ） 安裝類型:表面貼裝 封裝/外殼:18-VFQFN 供應商器件封裝:18-VQFN-HR（3.5x3.5） 標準包裝:1 |
| TPS54425 | 制造商:TI 制造商全稱:Texas Instruments 功能描述:4-A OUTPUT SINGLE SYNCHRONOUS STEP DOWN SWITCHER WITH INTEGRATED FET ( SWIFT?) |
| TPS54425_10 | 制造商:TI 制造商全稱:Texas Instruments 功能描述:4-A OUTPUT SINGLE SYNCHRONOUS STEP DOWN SWITCHER WITH INTEGRATED FET ( SWIFT?) |
發(fā)布緊急采購，3分鐘左右您將得到回復。