TS616 STMicroelectronics, TS616 Datasheet - Page 33

• Manufacturer Part Number: TS616
• Description: Multi video line driver (6 lines) and ADSL driver
• Manufacturer: STMicroelectronics

Specifications of TS616

• Low Noise: 2.5nV/√Hz
• High Output Current: 420mA
• High Slew Rate: 420V/µs
• -3db Bandwidth: 40MHz @ gain = 12dB on 25

TS616
Figure 70. Equivalent schematic - Ro is the synthesized impedance
Let us write Vo
that the current through R3 is negligible, we can calculate the output resistance, Ro:
After choosing the k factor, Rs will be equal to 1/2RL(k-1).
For a good impedance matching we assume that:
Equation 10
From
Equation 11
By fixing an arbitrary value of R2,
Finally, the values of R2 and R3 allow us to extract R1 from
Equation 12
with GL the required gain.
Table 6.
GL (gain for the loaded system)
Load viewed by each driver
Equation 9
R2 (= R4)
R3 (= R5)
Components calculation for impedance matching implementation
°
=kVo, where k is the matching factor varying between 1 and 2. If we assume
R1
Rs
and
Equation
Vi.Gi
Increasing the line level using active impedance matching
10, we derive:
R2
------- -
R3
R1
Ro
Equation 11
GL is fixed for the application requirements
GL= Vo/Vi= 0.5(1+2R2/R1+R2/R3)/(1-R2/R3)
2R2/[2(1-R2/R3)GL-1-R2/R3]
Arbitrarily fixed
R2/(1-Rs/0.5RL)
0.5RL(k-1)
kRL/2
=
=
=
1
Ro
---------------------------------------------------------- -
2 1
1
-- - RL
2
Ro
–
R3
2Rs
---------- -
RL
=
–
=
---------------------------- -
RL
R2
------- -
R3
--------------------
1
kVoRL
Iout
2R2
becomes:
–
+
R2
GL 1
2Rs
---------- -
2Rs1
RL
–
–
R2
------- -
R3
1/2
Equation
RL
6, so that:
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