TDA6650TT; TDA6651TT
NXP Semiconductors
5 V mixer/oscillator and low noise PLL synthesizer
NOISE
FIGURE
METER
LBIN
or
MBIN
27 Ω
NOISE
SOURCE
BNC
RIM
IFOUTA
INPUT
CIRCUIT
DUT
IFOUTB
V
CCA
fce750
NF = NFmeas − loss of input circuit (dB).
Fig 16. Noise figure (NF) measurement in low and mid band with asymmetrical IF output
BNC
connector
BNC
connector
Cs
TL
TL
Cc
Cp
Cc
Cp
Ls
to the IC
mixer input
to the IC
mixer input
Lp
Lp
mce452
a. Schematic 1
b. Schematic 2
For fRF = 50 MHz (Schematic 1)
For fRF = 300 MHz (Schematic 2)
Loss = 0 dB.
Loss = 0.5 dB.
Cs = 12 pF in parallel with a 0.8 pF to 8 pF trimmer.
Cp = 18 pF in parallel with a 0.8 pF to 8 pF trimmer.
Cc = 4.7 nF.
Cp = 8.2 pF in parallel with a 0.8 pF to 8 pF trimmer.
Cc = 4.7 nF.
Ls = 2 turns, 1.5 mm, wire = 0.4 mm air coil.
Lp = 2 turns, 1.5 mm, wire = 0.4 mm air coil.
TL = 50 Ω semi rigid cable, length = 75 mm.
Lp = 8 turns, 5 mm, wire = 0.4 mm air coil
TL = 50 Ω semi rigid cable, length = 75 mm.
For fRF = 150 MHz (Schematic 1)
Loss = 0 dB.
Cs = 0.8 pF to 8 pF trimmer.
Cp = 0.4 pF to 2.5 pF trimmer.
Cc = 4.7 nF.
Lp = 4 turns, 4.5 mm, wire = 0.4 mm air coil
TL = 50 Ω semi rigid cable, length = 75 mm.
Fig 17. Input circuit for optimum noise figure in low and mid band
TDA6650TT_6651TT_5
© NXP B.V. 2007. All rights reserved.
Product data sheet
Rev. 05 — 10 January 2007
35 of 54
NXP [ NXP ]
