參數(shù)資料
型號(hào)： TPS40077PWPRG4
廠商： TEXAS INSTRUMENTS INC
元件分類： 穩(wěn)壓器
英文描述： 2 A SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO16
封裝： GREEN, PLASTIC, HTSSOP-16
文件頁(yè)數(shù)： 7/43頁(yè)
文件大?。?/td> 847K
代理商： TPS40077PWPRG4
C u
V
IN * 8 V
R
SR
(1)
R t
0.2 V
f
SW
Q
g(TOT) ) IDD
(2)
SETTING THE SWITCHING FREQUENCY (PROGRAMMING THE CLOCK OSCILLATOR)
R
T +
1
f
SW(kHz)
17.82
10*6
* 23
kW
(3)
PROGRAMMING THE RAMP GENERATOR CIRCUIT AND UVLO
R
KFF + 0.131
R
T
V
UVLO(on) * 1.61
10*3
V
UVLO(on)
2
) 1.886
V
UVLO * 1.363 * 0.02
R
T * 4.87
10*5
R2
T
www.ti.com ..................................................................................................................................................... SLUS714D – JANUARY 2007 – REVISED APRIL 2009
where
V
VIN is the final value of the input voltage ramp
f
SW is the switching frequency
Q
g(TOT) is the combined total gate charge for both upper and lower MOSFETs (from MOSFET data sheet)
I
DD is the TPS40077 input current (3.5 mA maximum)
SR is the maximum allowed slew rate [12 ×104] (V/s)
The TPS40077 has independent clock oscillator and PWM ramp generator circuits. The clock oscillator serves as
the master clock to the ramp generator circuit. Connecting a single resistor from RT to ground sets the switching
frequency of the clock oscillator. The clock frequency is related to RT by:
The ramp generator circuit provides the actual ramp used by the PWM comparator. The ramp generator provides
voltage feed-forward control by varying the PWM ramp slope with line voltage, while maintaining a constant ramp
magnitude. Varying the PWM ramp directly with line voltage provides excellent response to line variations,
because the PWM is not required to wait for loop delays before changing the duty cycle. (See Figure 23).
The PWM ramp must reach approximately 1 V in amplitude during a clock cycle, or the PWM is not allowed to
start. The PWM ramp time is programmed via a single resistor (RKFF) connected from KFF VDD. RKFF, VSTART,
and RT are related by (approximately):
(4)
where
R
T and RKFF are in k
V
UVLO(on) is in V
This yields typical numbers for the programmed startup voltage. The minimum and maximum values may vary up
to ±15% from this number. Figure 16 through Figure 18 show the typical relationship of VUVLO(on), VUVLO(off) and
RKFF at three common frequencies.
The programmable UVLO circuit incorporates 20% hysteresis from the start voltage to the shutdown voltage. For
example, if the startup voltage is programmed to be 10 V, the controller starts when VDD reaches 10 V and shuts
down when VDD falls below 8 V. The maximum duty cycle begins to decrease as the input voltage rises to twice
the startup voltage. Below this point, the maximum duty cycle is as specified in the Electrical Characteristics
table. Note that with this scheme, the theoretical maximum output voltage that the converter can produce is
approximately two times the programmed startup voltage. For design, set the programmed startup voltage equal
to or greater than the desired output voltage divided by maximum duty cycle (85% for frequencies 500 kHz and
below). For example, a 5-V output converter should not have a programmed startup voltage below 5.9 V.
Figure 23 shows the theoretical maximum duty cycle (typical) for various programmed startup voltages.
Copyright 2007–2009, Texas Instruments Incorporated
15
Product Folder Link(s) :TPS40077
相關(guān)PDF資料
PDF描述
TPS40077PWPG4 2 A SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO16
TPS40090QPWRQ1 SWITCHING CONTROLLER, 1200 kHz SWITCHING FREQ-MAX, PDSO24
TPS40101RGET 1.3 A SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PQCC24
TPS40131RHBT SWITCHING CONTROLLER, 1200 kHz SWITCHING FREQ-MAX, PQCC32
TPS40131RHBTG4 SWITCHING CONTROLLER, 1200 kHz SWITCHING FREQ-MAX, PQCC32
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TPS40090 制造商:TI 制造商全稱:Texas Instruments 功能描述:HIGH FREQUENCY MULTIPHASE CONTROLLER
TPS40090EVM-001 功能描述:電源管理IC開(kāi)發(fā)工具 TPS40090-001 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
TPS40090EVM-002 功能描述:電源管理IC開(kāi)發(fā)工具 TPS40090-002 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
TPS40090PW 功能描述:DC/DC 開(kāi)關(guān)控制器 4 Ch Multiphase Buck DC/DC Controller RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開(kāi)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
TPS40090PW 制造商:Texas Instruments 功能描述:CONTROLLER IC
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*