U4065B Datasheet, PDF (9/34 Pages) TEMIC Semiconductors – FM Receiver

MIXIN1
MIXIN2
VREF
4807A–AUDR–05/04
Figure 13. Input 1 of the Double-balanced Mixer
V_REF
2.5k
15
ESD
U4065B
The parallel input resistance is 1.2 kΩ. The parallel input capacitance is about 9 pF.
When using the mixer in an unbalanced way, this pin needs to be grounded for RF sig-
nals by an external capacitance of a few nF. DC current is not allowed.
Figure 14. Input 2 of the Double-balanced Mixer
V_REF
2.5k
16
ESD
The parallel input resistance is 1.6 kΩ. The parallel input capacitance is about 7 pF. The
double sideband noise figure of the unbalanced mixer is about 7 dB. If using the mixer in
balanced mode, the noise figure will be reduced by about 0.8 dB.
Figure 15. Reference Voltage Output
V_S
200
4.6 V
17
ESD
The internal temperature-compensated reference voltage is 3.9 V and it is used as bias
voltage for most blocks. Therefore, the electrical characteristics of the U4065B are
mainly independent of the supply voltage. The internal output resistance of the refer-
ence voltage is less than 10 Ω. To avoid internal coupling across this pin, external
capacitors are required. The maximum output current is I_REF = 5 mA.
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