Philips Semiconductors
Wideband differential digital controlled
variable gain amplifier
Product specification
TDA9901
handbook, full pagewidth
FILTER
sine wave
generator
100 Ω
CMVGA 5
15 OUT 47 nF
IN 6
680 Ω
TDA9901TS
100
100 Ω
nF
680 Ω
INN 7
14 OUTN
47 nF
Vi 42
C1(1)
TDA8768
(ADC)
D0...11 12
Vi 43
C2(1)
dB
(2)
(3)
36
CLK
30 MHz
FCE306
(1) C1 and C2 represent the board line capacitance. They represent about 5 pF with the TDA8768 input capacitance. Special
care has to be taken to minimize this load in order to have the best dynamic performance.
(2) The HD2 and HD3 of the TDA8768 is lower than that measured on the TDA9901.This measurement method is preferred to
conventional methods due to its low contribution to the HD2.
(3) The chain measurement shows the harmonic distortion of the TDA9901 as the measurement from TDA8768 is negligible.
Fig.5 Dynamic distortion measurement diagram.
handbHoDok−,5h5alfpage
(dBc)
−60
FCE307
−65
−70
(1)
−75
(2)
−80
−85
10−1
1
10 f (MHz) 102
(1) HD3
(2) HD2
Typical condition; 2 V (p-p) differential output.
Fig.6 Harmonic distortion as a function of
frequency for minimum gain.
1999 Oct 08
handbHoDok−,5h5alfpage
(dBc)
−60
−65
FCE308
(1)
−70
(2)
−75
−80
−85
10−1
1
10 f (MHz) 102
(1) HD3
(2) HD2
Typical condition; 2 V (p-p) differential output.
Fig.7 Harmonic distortion as a function of
frequency for minimum gain plus 6 dB.
11