TS616 STMicroelectronics, TS616 Datasheet - Page 17

• 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
5
Intermodulation distortion product
The non-ideal output of the amplifier can be described by the following series, due to a non-
linearity in the input-output amplitude transfer:
where the single-tone input is V
fundamental, C
A one-frequency (one-tone) input signal contributes to a harmonic distortion. A two-tone
input signal contributes to a harmonic distortion and an intermodulation product.
This intermodulation product, or rather, the study of the intermodulation distortion of a two-
tone input signal is the first step in characterizing the amplifiers capability for driving multi-
tone signals.
The two-tone input is equal to:
giving:
In this expression, we can extract distortion terms and intermodulation terms from a single
sine wave: second-order intermodulation terms IM2 by the frequencies (
with an amplitude of C2A
(2
We can measure the intermodulation product of the driver by using the driver as a mixer via
a summing amplifier configuration. In doing this, the non-linearity problem of an external
mixing device is avoided.
Figure 45. Non-inverting summing amplifier for intermodulation measurements
1
-
t
2
), (2
=
Vin1
Vin1
50
50
C
0
1
+
1: 2
1: 2
C
n
1
is the amplitude of the harmonics of the output signal V
2
100
100
), (
A
Vin1
Vin1
sin
50
50
1
1
49.9
49.9
t
+ 2
2
49.9
49.9
1: 2
1: 2
+
and third-order intermodulation terms IM3 by the frequencies
B
V out
sin
2
100
100
) and (
in
=Asin t, and C
2
49.9
49.9
49.9
49.9
V
=
t
1k
1k
1k
1k
1k
1k
in
1k
1k
C
+
0
=
C
1
+
2
A
C 1 V in
300
300
300
300
A
sin
sin
2
+
+
_
_
_
_
+
+
1/2
1/2
1/2
1/2
) with an amplitude of (3/4)C3A
910
910
910
910
TS616
TS616
TS616
TS616
1
+
t
1
+
C 2 V
t
-Vcc
-Vcc
+Vcc
+Vcc
0
+
B
is the DC component, C
B
sin
in
sin
Vout diff.
Vout diff.
2
Intermodulation distortion product
+
2
t
C n V in
2
t
2
+
n
Rout1
Rout1
Rout2
Rout2
49.9
49.9
49.9
49.9
C
n
A
sin
100
100
1
out
t
1
1
+
-
(V
.
3
B
2:1
2:1
.
in
2
sin
) and (
) is the
50
50
2
t
n
1
17/37
2
)