TS4994EIKJT STMICROELECTRONICS [STMicroelectronics], TS4994EIKJT Datasheet - Page 27

• Manufacturer Part Number: TS4994EIKJT
• Description: 1.2 W differential input/output audio power amplifier with selectable standby
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

TS4994FC
4.6
Figure 92. PSRR vs. frequency with random
-100
-110
-120
-130
-140
-10
-20
-30
-40
-50
-60
-70
-80
-90
0
20
Vcc = 5V, Vripple = 200mVpp
Av = 1, Cin = 4.7 μ F
Δ R/R ≤ 0.1%, RL ≥ 8 Ω
Tamb = 25 ° C, Inputs = Grounded
The two following graphs show typical applications of the TS4994 with a random selection of
four
CMRR performance
For calculating CMRR performance, we consider that C
has no influence in the calculation of the CMRR.
We use the same kind of resistor (same tolerance) and ΔR is the tolerance value in %.
The following CMRR equation is valid for frequencies ranging from DC to about 1kHz.
The CMRR equation is (ΔR in %):
Example: With ΔR = 1%, the minimum CMRR is -34dB.
This example is a worst case scenario where each resistor has extreme tolerance. Ut
illustrates the fact that for CMRR, good matching is essential.
As with the PSRR, due to self-generated noise, the TS4994 CMRR limitation is about
-110dB.
Figure 94
worst-case conditions (ΔR=0.1%).
choice condition
Cb=1 μ F
Δ
100
R/R values with a 0.1% tolerance.
Cb=0.1 μ F
and
Cb=0.47 μ F
Frequency (Hz)
Figure 95
1000
Cb=0
show CMRR versus frequency and versus bypass capacitor C
CMRR
10000
20k
≤
20
×
Log
Figure 93. PSRR vs. frequency with random
⎡
⎢
⎣
(
10000
-100
-110
-120
-130
-140
Δ
-10
-20
-30
-40
-50
-60
-70
-80
-90
R
0
20
×
−
200
Vcc = 2.5V, Vripple = 200mVpp
Av = 1, Cin = 4.7 μ F
Δ R/R ≤ 0.1%, RL ≥ 8 Ω
Tamb = 25 ° C, Inputs = Grounded
choice condition
Δ
R
in
Cb=1 μ F
2
100
)
and C
⎤
⎥
⎦
Cb=0.1 μ F
(
dB
Cb=0.47 μ F
Frequency (Hz)
feed
)
Application information
have no influence. C
1000
Cb=0
10000
20k
27/35
b
b
in