TS616 STMicroelectronics, TS616 Datasheet - Page 31

• 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
10
Increasing the line level using active impedance
matching
With passive matching, the output signal amplitude of the driver must be twice the amplitude
on the load. To go beyond this limitation an active matching impedance can be used. With
this technique, it is possible to maintain good impedance matching with an amplitude on the
load higher than half of the output driver amplitude. This concept is shown in
differential line.
Figure 68. TS616 as a differential line driver with active impedance matching
Component calculation
Let us consider the equivalent circuit for a single-ended configuration, as shown in
Figure
Figure 69. Single-ended equivalent circuit
69.
Vi
Vi
100n
100n
1k
1k
10
Vcc+
GND
½ R1
½ R1
100n
Vi
Vi
Increasing the line level using active impedance matching
1/2
1/2
R1
R1
R2
R2
+
_
+
_
+
+
+
+
_
_
_
_
Vcc/2
R2
R3
R5
R4
R3
R3
Vcc+
GND
Vcc+
GND
Vo°
Vo°
Vo°
Vo°
Rs1
Rs1
-1
-1
-1
-1
Rs2
Rs1
Vo
Vo
Vo
Vo
10n
½ RL
½ RL
1
RL
Transformer
Hybrid
1:n
&
Figure 68
100
31/37
for a