TDA6502 Datasheet, PDF (24/44 Pages) NXP Semiconductors – 5 V mixers/oscillators and synthesizers for cable TV and VCR 2-band tuners

Philips Semiconductors
5 V mixers/oscillators and synthesizers for
cable TV and VCR 2-band tuners
13 TEST AND APPLICATION INFORMATION
13.1 Test circuits
Preliminary specification
TDA6502; TDA6502A;
TDA6503; TDA6503A
handbook, full pagewidth
signal
50 Ω source
VHFIN IFOUT
27 Ω
e
Vmeas V
50 Ω
Vi
D.U.T.
Vo V'meas
spectrum
analyzer
50 Ω
RMS
voltmeter
FCE577
Z_i >> 50 Ω ⇒ V_i = 2 × V_meas = 80 dBµV
V_i = V_meas + 6 dB = 80 dBµV
V_o = V’_meas × ^{5----0---5--+}-0----2---7--
G_v = 20 log ^V-V----o-_i
Fig.12 Gain measurement in VHF band.
handbook, full pagewidth
BNC ^C1
L1
I1
PCB
plug
C2
RIM-RIM
(a)
I3
PCB
BNC ^C3
I2
plug
RIM-RIM
C4
(b)
FCE578
(a) For f_RF = 50 MHz:
mixer A frequency response measured = 57 MHz, loss = 0 dB
image suppression = 16 dB
C1 = 9 pF
C2 = 15 pF
L1 = 7 turns (∅ 5.5 mm, wire ∅ = 0.5 mm)
l1 = semi rigid cable (RIM) of 5 cm long
(semi rigid cable (RIM); 33 dB/100 m; 50 Ω; 96 pF/m).
(b) For f_RF = 150 MHz:
mixer A frequency response measured = 150.3 MHz, loss = 1.3 dB
image suppression = 13 dB
C3 = 5 pF
C4 = 25 pF
l2 = semi rigid cable (RIM): 30 cm long
l3 = semi rigid cable (RIM) of 5 cm long
(semi rigid cable (RIM); 33 dB/100 m; 50 Ω; 96 pF/m).
Fig.13 Input circuit for optimum noise figure in VHF band.
2000 Mar 16
24