TEF6700HL NXP Semiconductors, TEF6700HL Datasheet - Page 10

• Manufacturer Part Number: TEF6700HL
• Description: Car Radio Tuner Front-end For Digital If
• Manufacturer: NXP Semiconductors

Philips Semiconductors
7
7.1
The FM quadrature mixer converts FM RF
(64 to 162.55 MHz) to an IF of 10.7 MHz. The FM mixer
provides inherent image rejection and high RF sensitivity.
The image rejection can be switched from ‘low’ injection
Local Oscillator (LO) to ‘high’ injection LO via the I
The mixer gain can be increased by 6 dB via the I
In this case the threshold of the FM keyed AGC has to be
lowered by 6 dB to prevent the mixer from being
overloaded.
The mixer is capable of tuning the:
7.2
The buffer output (pin WBFLAG) is HIGH for weather band
mode.
7.3
The varactor tuned LC oscillator provides the local
oscillator signal for both FM and AM mixer 1. It has a
frequency range from 159.9 to 248.2 MHz.
7.4
The crystal oscillator provides a 20.5 MHz signal that is
used for:
7.5
The fast synthesizer PLL tuning system with local control
is used for inaudible RDS updating.
2003 Oct 21
US FM and US IBOC DAB from 87.9 to 107.9 MHz
US weather FM from 162.4 to 162.55 MHz
Europe FM from 87.5 to 108 MHz
Japan FM from 76 to 91 MHz
East Europe FM from 64 to 74 MHz.
Reference frequency for frequency synthesizer PLL
Local oscillator for AM mixer 2
Reference frequency for the IF counter
Timing signal for the RDS update algorithm.
Car radio tuner front-end for digital IF
FUNCTIONAL DESCRIPTION
FM I/Q-mixer
Buffer output for weather band flag
VCO
Crystal oscillator
PLL
2
2
C-bus.
C-bus.
10
7.6
To reduce the number of manual alignments in production
the following I
(DAA) functions are included:
7.7
The AGC threshold is programmable and the keyed AGC
function is switchable via the I
occurs at the input of the FM mixer. If the keyed AGC
function is activated, the AGC is keyed only by the
narrow-band level. The AGC PIN diode drive can be
activated via the I
tuning. The AGC sources a constant 10 mA current into
the FM PIN diode in AM mode.
7.8
The FM IF amplifier provides 10.5 or 14 dB gain,
selectable via the I
dynamic range. In IBOC DAB mode (activated via I
FM IF is buffered and directly fed to FM IF AGC bypassing
the second FM ceramic filter.
7.9
This is a linear FM IF AGC amplifier with multiplexed
inputs for FM standard and FM IBOC DAB. The gain
controlled FM IF is output by the multiplexed
FM IF/AM IF2 buffer for a car IF DSP IC (e.g. SAA7724H).
FM RF DAA
– 7-bit DAA circuitry for the conversion of the VCO
FM and AM level DAA
– Level DAA circuitry for alignment of slope (3-bit) and
tuning voltage to a controlled alignment voltage for
the FM antenna tank circuit
starting point (5-bit) of the level curve.
DAA
FM keyed AGC
FM IF amplifier
FM IF AGC
2
C-bus controlled Digital Auto Alignment
2
C-bus as a local function for search
2
C-bus with high linearity over a wide
2
C-bus. AGC detection
Product specification
TEF6700HL
2
C-bus)