TEF6730A NXP Semiconductors, TEF6730A Datasheet - Page 8

• Manufacturer Part Number: TEF6730A
• Description: Tef6730a Front-end For Digital-if Car Radio
• Manufacturer: NXP Semiconductors

NXP Semiconductors
7. Functional description
TEF6730A_1
Product data sheet
7.1 FM mixer 1
7.2 FM RF AGC
7.3 Antenna DAA1 and DAA2
Table 3.
The FM quadrature mixer converts FM RF (65 MHz to 108 MHz) to an IF frequency of
10.7 MHz. The FM mixer provides high image rejection, a large dynamic range and
selectable mixer gain. The image rejection can be selected between low injection of LO
and high injection of LO via the I
RF input for weather band is available.
AGC detection is at the FM front-end mixer input and the AM/FM IF AGC amplifier input,
both with programmable AGC thresholds. When the threshold is exceeded, the PIN diode
drive circuit sources a current to an external PIN diode circuit, keeping the RF signal level
constant.
Keyed AGC function is selectable via the I
from the IF DSP.
The AGC PIN diode drive circuit can optionally deliver a fixed current as a local function.
In AM mode, the AGC PIN diode drive circuit can be set to generate a fixed source current
into the external FM PIN diode circuitry.
The antenna DAA1 measures the VCO tuning voltage and multiplies it with a factor
defined by the 7-bit DAA1 setting to generate a tuning voltage for the FM antenna tank
circuit. If a second FM tank circuit is applied, the tuning voltage can be derived from the
antenna DAA2 output. The antenna DAA2 measures the output voltage of the antenna
DAA1 and multiplies it with a factor defined by the 4-bit DAA2 setting.
Symbol
SCL
DGND
FREF1
FREF2
VREF
GND
V
IFOUT1
IFOUT2
IFAGCMSB
IFAGCLSB
V
IFGND
IFAGCBIAS
CC
CC(IF)
Pin description
Pin
51
52
53
54
55
56
57
58
59
60
61
62
63
64
Rev. 01 — 21 February 2007
…continued
Description
I
digital ground
reference frequency input 1
reference frequency input 2
reference voltage noise decoupling
ground
supply voltage (8.5 V)
IF AGC amplifier output 1
IF AGC amplifier output 2
MSB input for IF AGC amplifier gain setting
LSB input for IF AGC amplifier gain setting
IF AGC amplifier supply voltage
IF AGC amplifier ground
bias voltage decoupling for IF AGC amplifier
2
C-bus clock line input
2
C-bus independently of the band selection. A separate
2
C-bus and uses the in-band level information
Front-end for digital-IF car radio
TEF6730A
© NXP B.V. 2007. All rights reserved.
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