mt88ebnr Zarlink Semiconductor, mt88ebnr Datasheet - Page 16

• Manufacturer Part Number: mt88ebnr
• Description: 4-wire Calling Number Identification Circuit 2 4-wire Cnic2 Semiconductor Inc
• Manufacturer: Zarlink Semiconductor

Gain Setting Resistor Calculation Example for Figure 8:
•
•
•
•
For the desired nominal Vdd, use Figure 8 to determine approximate A
For the GS1 op-amp, start with the 0 dB gain setting resistor values of R5
these values are 53K7, 60K4 and 464 K respectively. Keep C1,C2,R1,R2,R3,R4 as in Figure 7 to maintain
the highpass corner frequency constant for all gain settings.
For the desired gain setting of A
Repeat for R
R7
R5
1/R6
Av
Av
= R7
= R5
Av
= 1/R5
10
0dB
0dB
1.00
0.95
0.90
0.85
0.80
0.75
0.70
0.65
0.60
0.55
0.50
, R
11
3.0
x A
x A
, R
Av
V
V
- 1/R7
12
0.668
0.531
for the GS2 op-amp.
Figure 8 - Gain Ratio as a Function of Nominal Vdd
Av
v
:
Gain ratio for
Bellcore GS1, GS2
ETSI GS2 op amps
3.5
Zarlink Semiconductor Inc.
Calculate R6
the closest standard resistor value as R6
Scaled for desired gain. Choose
the closest standard resistor value as R7
Actual A
Scaled for good common mode range. Choose
the closest standard resistor value as R5
MT88E45
Nominal Vdd (Volts)
16
v
from now on is R7
4.0
Av
so that R5
Gain ratio for ETSI
GS1 op amp
Av
v
.
=R6
Av
4.5
0dB
/R7
Av
, R6
0db
|| R7
0dB
Av
and R7
Av
Av
Av
. Choose
.
.
.
0.794
0dB
5.0
Data Sheet
. In Figure 7