參數(shù)資料
型號(hào): TPS62751DSKR
廠商: TEXAS INSTRUMENTS INC
元件分類: 穩(wěn)壓器
英文描述: 1.8 A SWITCHING REGULATOR, 2500 kHz SWITCHING FREQ-MAX, PDSO10
封裝: 2.50 X 2.50 MM, GREEN, PLASTIC, SON-10
文件頁(yè)數(shù): 11/30頁(yè)
文件大?。?/td> 1733K
代理商: TPS62751DSKR
(
)
I
× V
- V
IN
OUT
C
=
min
f ×
V × V
OUT
D
I× t
Capacitance =
V
1.3A ×1.154ms
Capacitance =
= 4.2mF
350mV
www.ti.com ................................................................................................................................................. SLVS955A – JULY 2009 – REVISED SEPTEMBER 2009
OUTPUT CAPACITOR SELECTION
The TPS62750 has been specifically internally compensated to operate with large capacitance values. But to
maintain loop stability of the device, it is recommended to use a small ceramic capacitor placed as close as
possible to the VOUT and GND pins of the IC in parallel with the large holdup capacitor. To get an estimate of the
small ceramic recommended minimum output capacitance, Equation 4 can be used.
(4)
Parameter f is the switching frequency and
ΔV is the maximum allowed ripple.
With a chosen ripple voltage of 10 mV, a minimum effective capacitance of 2.7
μF is needed. The total ripple is
larger due to the ESR of the output capacitor. This additional component of the ripple can be calculated using
Δ
VESR = IOUT x RESR.
A capacitor with a value in the range of the calculated minimum should be used. This is required to maintain
control loop stability. There are no additional requirements regarding minimum ESR. There is no upper limit for
the output capacitance value. Larger capacitors cause lower output voltage ripple as well as lower output voltage
drop during load transients.
Note that ceramic capacitors have a DC Bias effect, which will have a strong influence on the final effective
capacitance needed. Therefore the right capacitor value has to be chosen very carefully. Package size and
voltage rating in combination with material are responsible for differences between the rated capacitor value and
the effective capacitance.
To calculate the value of the effective capacitance required to buffer a GSM transmission pulse, the following
equations can be used:
(5)
Assuming the DCDC supplies ~700mA, the rest of the energy to supply the GSM transmission pulse must come
from the capacitor.
ICAP = IGSM - IDCDC
ICAP = 2A - 700mA = 1.3A
Assuming a GSM transmission pulse width of 1.154ms and allowing a maximum voltage drop on the output of
350mV, the effective capacitance required is:
(6)
Table 4. List of Capacitors
COMPONENT REFERENCE
PART NUMBER
MANUFACTURER
VALUE
CO
GRM188R60J106M69D
Murata
10
μF
6TPG150M
Sanyo POSCAP
150
μF
CBULK
592D158X06R3X2T25H
Vishay
1.5mF
592D228X06R3X2T22H
Vishay
2.2mF
AVERAGE INPUT CURRENT LIMIT
The average input current is set by selecting the correct external resistor value correlating to the required current
limit. The current limit can be selected between a high current limit (ILIM_U) and a lower limit (ILIM_L) by toggling
the H/L pin high or low. This has the added benefit that of allowing a device first plugged into the USB port to
enumerate at 100mA before switching over to the high power mode (500mA). The equations below are a
guideline for selecting the correct resistor value:
Copyright 2009, Texas Instruments Incorporated
19
Product Folder Link(s) :TPS62750, TPS62751
相關(guān)PDF資料
PDF描述
TPS63000IDRCRQ1 2.1 A SWITCHING REGULATOR, 1500 kHz SWITCHING FREQ-MAX, PDSO10
TPS65011RGZT 2-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC48
TPS65023QRHARQ1 POWER SUPPLY SUPPORT CKT, PQCC40
TPS65040ZQER 8-CHANNEL POWER SUPPLY MANAGEMENT CKT, PBGA71
TPS650531IRGERQ1 POWER SUPPLY SUPPORT CKT, PQCC24
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TPS62751DSKT 功能描述:直流/直流開(kāi)關(guān)調(diào)節(jié)器 2.25MHz 92% Eff Step Down Converter RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開(kāi)關(guān)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(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5
TPS62770EVM-734 功能描述:TPS62770 - DC/DC, Step Up or Down 2, Non-Isolated Outputs Evaluation Board 制造商:texas instruments 系列:- 零件狀態(tài):有效 主要用途:DC/DC,步升/步降 輸出和類型:2,非隔離 功率 - 輸出:- 電壓 - 輸出:- 電流 - 輸出:- 電壓 - 輸入:2.5 V ~ 5.5 V 穩(wěn)壓器拓?fù)?降壓-升壓 頻率 - 開(kāi)關(guān):- 板類型:完全填充 所含物品:板 使用的 IC/零件:TPS62770 標(biāo)準(zhǔn)包裝:1
TPS62770YFPT 功能描述:Buck, Boost Switching Regulator IC Positive Programmable 1V, 4.5V (12V) 2 Output 300mA, 30mA, 100mA, 200mA 16-XFBGA, DSBGA 制造商:texas instruments 系列:- 包裝:剪切帶(CT) 零件狀態(tài):有效 功能:升壓,降壓 輸出配置:正 拓?fù)?降壓,升壓 輸出類型:可編程 輸出數(shù):2 電壓 - 輸入(最小值):2.5V 電壓 - 輸入(最大值):5.5V 電壓 - 輸出(最小值/固定):1V,4.5V(12V) 電壓 - 輸出(最大值):3V,15V 電流 - 輸出:300mA,30mA,100mA,200mA 頻率 - 開(kāi)關(guān):1.05MHz 同步整流器:是 工作溫度:-40°C ~ 85°C(TA) 安裝類型:表面貼裝 封裝/外殼:16-XFBGA,DSBGA 供應(yīng)商器件封裝:16-DSBGA 標(biāo)準(zhǔn)包裝:1
TPS63000DRCR 功能描述:直流/直流開(kāi)關(guān)調(diào)節(jié)器 96% Buck Boost Converter RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開(kāi)關(guān)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(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5
TPS63000DRCRG4 功能描述:直流/直流開(kāi)關(guān)調(diào)節(jié)器 96% Buck Boost Converter RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開(kāi)關(guān)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(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5