參數(shù)資料
型號: TS4871IDT
廠商: STMICROELECTRONICS
元件分類: 音頻/視頻放大
英文描述: 1 W, 1 CHANNEL, AUDIO AMPLIFIER, PDSO8
封裝: SOP-8
文件頁數(shù): 18/28頁
文件大小: 1491K
代理商: TS4871IDT
TS4871
25/28
s Note on how to use the PSRR curves
(page 7)
We have finished a design and we have chosen
the components values :
Rin=Rfeed=22k
Cin=100nF
Cb=1F
Now, on fig. 13, we can see the PSRR (input
grounded) vs frequency curves. At 217Hz we have
a PSRR value of -36dB.
In reality we want a value about -70dB. So, we
need a gain of 34dB !
Now, on fig. 12 we can see the effect of Cb on the
PSRR (input grounded) vs. frequency. With
Cb=100F, we can reach the -70dB value.
The process to obtain the final curve (Cb=100F,
Cin=100nF, Rin=Rfeed=22k
) is a simple transfer
point by point on each frequency of the curve on
fig. 13 to the curve on fig. 12. The measurement
result is shown on the next figure.
Fig. 85 : PSRR changes with Cb
What is the PSRR ?
The PSRR is the Power Supply Rejection Ratio.
It's a kind of SVR in a determined frequency range.
The PSRR of a device, is the ratio between a
power supply disturbance and the result on the
output. We can say that the PSRR is the ability of
a device to minimize the impact of power supply
disturbances to the output.
How do we measure the PSRR ?
Fig. 86 : PSRR measurement schematic
s Principle of operation
We fixed the DC voltage supply (Vcc), the AC
sinusoidal ripple voltage (Vripple) and no supply
capacitor Cs is used
The PSRR value for each frequency is:
Remark : The measure of the Rms voltage is not a
Rms selective measure but a full range (2 Hz to
125 kHz) Rms measure. It means that we
measure the effective Rms signal + the noise.
sHigh/low cut-off frequencies
For their calculation, please check this "Frequency
Response Gain vs Cin, & Cfeed" graph:
10
100
1000
10000
100000
-70
-60
-50
-40
-30
Cin=100nF
Cb=100
F
Cin=100nF
Cb=1
F
Vcc = 5, 3.3 & 2.6V
Rfeed = 22k, Rin = 22k
Rg = 100
, RL = 8
Tamb = 25
°C
P
S
RR
(
d
B)
Frequency (Hz)
Vripple
Vcc
Rin
Cin
Rg
100 Ohms
Cb
Rfeed
4
3
2
1
5
8
Vin-
Vin+
-
+
-
+
Bypass
Standby
Bias
6
Vout1
Vout2
Av=-1
TS4871
Vs-
Vs+
RL
Vcc
GND
7
PSRR d B
() = 20 x Log
10
Rm s Vrippl e
()
Rm s Vs + - Vs-
()
---------------------------------------------
10
100
1000
10000
-25
-20
-15
-10
-5
0
5
10
Rin = Rfeed = 22k
Tamb = 25
°C
Cfeed = 2.2nF
Cfeed = 680pF
Cfeed = 330pF
Cin = 470nF
Cin = 82nF
Cin = 22nF
G
a
in
(dB
)
Frequency (Hz)
相關(guān)PDF資料
PDF描述
TS4871ID 1 W, 1 CHANNEL, AUDIO AMPLIFIER, PDSO8
TS4871IST 1 W, 1 CHANNEL, AUDIO AMPLIFIER, PDSO8
TS4871IQT 1 W, 1 CHANNEL, AUDIO AMPLIFIER, DSO8
TS4871IS 1 W, 1 CHANNEL, AUDIO AMPLIFIER, PDSO8
TS488IQT 0.13 W, 2 CHANNEL, AUDIO AMPLIFIER, PDSO8
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TS4871IQT 功能描述:音頻放大器 1W Mono Audio Power Amplifier RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel
TS487-1IQT 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Amplifier. Other
TS4871IS 制造商:未知廠家 制造商全稱:未知廠家 功能描述:AUDIO AMPLIFIER|SINGLE|TSSOP|8PIN|PLASTIC
TS4871IST 功能描述:音頻放大器 1W Audio Power Amp RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel
TS4872 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:RAIL TO RAIL INPUT/OUTPUT 1W AUDIO POWER AMPLIFIER WITH STANDBY MODE