參數(shù)資料
型號(hào): TPS51317RGBR
廠商: TEXAS INSTRUMENTS INC
元件分類: 穩(wěn)壓器
英文描述: SWITCHING REGULATOR, 1500 kHz SWITCHING FREQ-MAX, PQCC20
封裝: 4 X 3.50 MM, GREEN, PLASTIC, QFN-20
文件頁數(shù): 13/28頁
文件大?。?/td> 1000K
代理商: TPS51317RGBR
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
÷
D
+
÷
è
=
-
÷
÷
D
-
÷
÷
è
è
2
VOUT
SW
LOAD max
MIN off
IN min
OUT min_ under
VOUT
IN min
SW
VOUT
LOAD insert
MIN off
IN min
V
t
L
I
t
V
C
V
2
V
t
V
(
)
(
)
(
)
(
)
D
=
D
2
OUT
LOAD max
OUT min_ over
VOUT
LOAD release
L
I
C
2
V
=
=
p
C
M
0
OUT
S
R
G
1
f
190 kHz
2
C
R
p
W
p
m
=
W
0
S
OUT
C
M
f
R
2
C
190 kHz
53m
2
80 F
R
5 k
G
1mS
=
p
=
0
Z
C
f
1
f
2
R
C
10
SLUSAH9
– MARCH 2011
The minimum valley OCL is 6 A over process and temperature, and IP-P = 1.5 A, the minimum DC OCL is
calculated to be 6.75A.
Step Six
Determine the output capacitance.
To determine COUT based on transient and stability requirement, first calculate the the minimum output
capacitance for a given transient.
Equation 10 and Equation 9 can be used to estimate the amount of capacitance needed for a given dynamic load
step/release. Please note that there are other factors that may impact the amount of output capacitance for a
specific design, such as ripple and stability. Equation 10 and Equation 9 are used only to estimate the transient
requirement, the result should be used in conjunction with other factors of the design to determine the necessary
output capacitance for the application.
(9)
(10)
Equation 9 and Equation 10 calculate the minimum COUT for meeting the transient requirement, which is 84 F
assuming the following:
±3% voltage allowance for load step and release
MLCC capacitance derating of 60% due to DC and AC bias effect
In this reference design, 6, 22-
F capacitors are used in order to provide this amount of capacitance.
Step Seven
Determine the stability based on the output capacitance COUT.
In order to achieve stable operation. The 0-dB frequency, f0 should be kept less than 1/5 of the switching
frequency (1 MHz). (See Figure 4)
where
RS = RDS(on) × GMC × RLOAD
(11)
.
(12)
Using 6, 22-
F capacitors, the compensation resistance, RC can be calculated to be approximately 5 kΩ.
The purpose of the comparator capacitor (CC) is to reduce the DC component to obtain high DC feedback gain.
However, as it causes phase delay, another zero to cancel this effect at f0 is needed. This zero can be
determined by values of CC and the compensation resistor, RC.
(13)
And since RC has previously been derived, the value of CC is calculated to be 2.2 nF. In order to further boost
phase margin, a value of 3.3-nF is chosen for this reference design.
20
Copyright
2011, Texas Instruments Incorporated
Product Folder Link(s): TPS51317
相關(guān)PDF資料
PDF描述
TPS51427ARHBR DUAL SWITCHING CONTROLLER, PQCC32
TPS51427ARHBT DUAL SWITCHING CONTROLLER, PQCC32
TPS51461RGET SWITCHING REGULATOR, 1000 kHz SWITCHING FREQ-MAX, PQCC24
TPS51511RHLT SWITCHING CONTROLLER, 350 kHz SWITCHING FREQ-MAX, PQCC20
TPS53114PW SWITCHING CONTROLLER, 700 kHz SWITCHING FREQ-MAX, PDSO16
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TPS51317RGBT 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 3.3V/5Vin,6A,DCAP Mode Sync Converter RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT
TPS51362RVER 制造商:Texas Instruments 功能描述:22V INPUT, 10A INTEGRATED FET 制造商:Texas Instruments 功能描述:IC REG BUCK SYNC ADJ 10A 28VQFN
TPS51362RVET 制造商:Texas Instruments 功能描述:22V INPUT, 10A INTEGRATED FET 制造商:Texas Instruments 功能描述:IC REG BUCK SYNC ADJ 10A 28VQFN
TPS51363 制造商:TI 制造商全稱:Texas Instruments 功能描述:22-V Input, 8-A or 10-A Converter With Integrated FET
TPS51363RVER 制造商:Texas Instruments 功能描述:Conv DC-DC Single Step Down 3V to 22V 28-Pin VQFN EP T/R 制造商:Texas Instruments 功能描述:IC REG BCK SYNC ADJ 10/8A 28VQFN