TEF6903AH/V5S,518 NXP Semiconductors, TEF6903AH/V5S,518 Datasheet - Page 9

• Manufacturer Part Number: TEF6903AH/V5S,518
• Description: IC CAR RADIO SGL CHIP CIRC 80QFP
• Manufacturer: NXP Semiconductors

Specifications of TEF6903AH/V5S,518

• Modulation Or Protocol: AM, FM, WB
• Applications: AM/FM Radio Receiver
• Current - Receiving: 102mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 8 V ~ 9 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Frequency: -
• Sensitivity: -
• Memory Size: -
• Data Rate - Maximum: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 935288823518

NXP Semiconductors
TEF6904A_3
Product data sheet
7.10 Crystal oscillator
7.11 Tuning PLL
7.12 Antenna DAA
7.13 AM RF AGC control
7.14 AM mixer 1
7.9 VCO and dividers
The varactor tuned LC oscillator together with the dividers provides the local oscillator
signal for both AM and FM front-end mixers. The VCO has an operating frequency of
approximately 160 MHz to 250 MHz. In FM mode the VCO frequency is divided by 2 or 3.
These dividers generate in-phase and quadrature-phase output signals used in the
FM front-end mixer for image rejection. In AM mode the VCO frequency is divided by 6, 8,
10, 16 or 20 depending on the selected AM band. The amplitude of the VCO is controlled
by a digital AGC to ensure a safe oscillation start-up at a wide range of the loaded Q.
The crystal oscillator provides a 20.5 MHz signal. A divider-by-two generates in-phase
and quadrature-phase mixer frequencies for the conversion from IF1 to IF2 including
image rejection. The reference divider generates from the crystal frequency various
reference frequencies for the tuning PLL. Also timing signals for the sequential machine
as well as references for the integrated FM channel filter, the stereo decoder and the
integrated audio filters are derived from the crystal reference.
The tuning PLL locks the VCO frequency divided by the programmable divider ratio to the
reference frequency. Due to the combination of different charge pump signals in the
PLL loop filter, the loop parameters are adapted dynamically. Tuning to different
RF frequencies is done by changing the programmable divider ratio. The tuning step size
is selected with the reference frequency divider setting.
For FM operation the antenna Digital Auto Alignment (DAA) measures the VCO tuning
voltage and multiplies it with a factor defined by the 7-bit DAA setting to generate a tuning
voltage for the FM antenna tank circuit (RF selectivity). In AM mode the DAA setting
controls a fixed voltage.
The AM front-end is designed for the application of an external Junction Field Effect
Transistor (JFET) low noise amplifier with cascode AGC and PIN diode AGC both
controlled by an integrated AGC control circuit. Four AGC thresholds of the detector at the
first mixer input are selectable via I
AMIF2 input prevent undesired overload (see
out via I
reverse biasing of the PIN diode, when the AGC is not active to achieve a low parasitic
capacitance.
The large dynamic range AM mixer converts AM RF (144 kHz to 26.1 MHz) to an IF
frequency of 10.7 MHz.
2
C-bus. The PIN diode current drive circuit includes a pull-up current source for
Rev. 03 — 20 March 2008
2
C-bus. Detectors at the RF mixer input and at the
Figure
39). AGC information can be read
TEF6904A
Integrated car radio
© NXP B.V. 2008. All rights reserved.
9 of 108