TDA7541B STMicroelectronics, TDA7541B Datasheet - Page 26

• Manufacturer Part Number: TDA7541B
• Description: IC TUNER AM/FM CAR RADIO 64-LQFP
• Manufacturer: STMicroelectronics

Specifications of TDA7541B

• Modulation Or Protocol: AM, FM
• Applications: Automotive Audio
• Current - Receiving: 48mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 7.7 V ~ 9 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Frequency: -
• Sensitivity: -
• Memory Size: -
• Data Rate - Maximum: -

Functional description
4
4.1
4.1.1
4.1.2
4.1.3
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Functional description
FM part
Mixer 1 AGC and IF amplifier
FM quadrate I/Q-mixer converts FM RF to IF1 of 10.7 MHz. The mixer provides inherent
image rejection and wide dynamic range with low noise and large input signal performance.
For accurate image rejection the phase-error of I/Q can be compensated by software (PH).
It is capable of tuning the US FM, US weather (dedicated WB input), Europe FM, Japan FM
and East Europe FM bands:
The AGC operates on different sensitivities and bandwidths in order to improve the input
sensitivity and dynamic range. AGC thresholds are programmable by software (RFAGC,
IFAGC, and KAGC). The output signal is a controlled current for pin diode attenuator.
A 10.7 MHz programmable amplifier (IFG) correct the IF ceramic insertion loss and the
costumer level plan application.
Mixer2, limiter, FM demodulator and spike cancellation
In the 2nd mixer stage the first 10.7 MHz IF is converted into the second 450 kHz IF.
The fully integrated sample and hold FM demodulator including spike cancellation (DSB)
converts the IF signal from the 450 kHz limiter (limiter gain 80 dB typ.) to the FM multiplex
output signal with very low distortion.
The sensitivity of spike blanking can be set via I
Quality detection and ISS
Field strength
Parallel to mixer2 input a 10.7 MHz limiter generates a signal for digital IF counter and field
strength voltage V
adjacent channel and multi path detection and is available at PIN27 (FSU) in a range of 0 V
to 5 V. The offset and slope of FSU signal can be adjusted via I
application adaptation.
The voltage VFSWO including offset adjust is externally filtered at PIN37 (FSWO) and used
for weak signal mute function and generation of ISS filter control signals in weak signal
condition. It is possible to combine the IF counter result with this voltage VFSWO by
programmable comparator threshold (SSTH).
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–
–
–
–
US FM = 87.9 to 107.9 MHz
US weather = 162.4 to 162.55 MHz
Europe FM = 87.5 to 108 MHz
Japan FM = 76 to 91 MHz
East Europe FM = 65.8 to 74 MHz
FSUint
. This internal voltage V
Doc ID 16048 Rev 1
FSUint
2
C bus.
is used for AM IF noise blanker,
2
C bus (FSWO and SL) for
TDA7541B