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): 8/35頁
文件大小: 1356K
代理商: TPS54418RTER
VSENSE
COMP
VO
R1
R3
C1
C2
R2
CO RO
gm
225 uA/V
0.8 V
PowerStage
13.0 A/V
PH
RESR
COUT
RL
b
a
c
VO
RL
VC
fp
fz
Adc
gmps
RESR
COUT
s
1+
2 ×
z
vo
= Adc
vc
s
1+
2 ×
p
÷
p
è
÷
p
è
ps
L
Adc = gm
R
SLVS946A – MAY 2009 – REVISED MAY 2010
www.ti.com
Figure 30. Small Signal Model for Loop Response
SIMPLE SMALL SIGNAL MODEL FOR PEAK CURRENT MODE CONTROL
Figure 30 is a simple small signal model that can be used to understand how to design the frequency
compensation. The TPS54418 power stage can be approximated to a voltage controlled current source (duty
cycle modulator) supplying current to the output capacitor and load resistor. The control to output transfer
function is shown in Equation 7 and consists of a dc gain, one dominant pole and one ESR zero. The quotient of
the change in switch current and the change in COMP pin voltage (node c in Figure 30) is the power stage
transconductance. The gm for the TPS54418 is 13.0 A/V. The low frequency gain of the power stage frequency
response is the product of the transconductance and the load resistance as shown in Equation 8. As the load
current increases and decreases, the low frequency gain decreases and increases, respectively. This variation
with load may seem problematic at first glance, but the dominant pole moves with load current [see Equation 9].
The combined effect is highlighted by the dashed line in the right half of Figure 31. As the load current
decreases, the gain increases and the pole frequency lowers, keeping the 0-dB crossover frequency the same
for the varying load conditions which makes it easier to design the frequency compensation.
Figure 31. Simple Small Signal Model and Frequency Response for Peak Current Mode Control
(7)
(8)
16
Copyright 2009–2010, Texas Instruments Incorporated
Product Folder Link(s): TPS54418
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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?)