tda5251f1 Infineon Technologies Corporation, tda5251f1 Datasheet - Page 8

• Manufacturer Part Number: tda5251f1
• Description: Ask/fsk 315mhz Wireless Transceiver
• Manufacturer: Infineon Technologies Corporation

Confidential
1
1.1
The IC is a low power consumption single chip FSK/ASK Transceiver for the frequency band
315MHz. The IC combines a very high level of integration and minimum external part count. The
device contains a low noise amplifier (LNA), a double balanced mixer, a fully integrated VCO, a PLL
synthesizer, a crystal oscillator with FSK modulator, a limiter with RSSI generator, an FSK
demodulator, a data filter, a data comparator (slicer), a positive and a negative data peak detector,
a highly efficient power amplifier and a complex digital timing and control unit with I
microcontroller interface. Additionally there is a power down feature to save battery power.
The transmit section uses direct ASK modulation by switching the power amplifier, and crystal
oscillator detuning for FSK modulation. The necessary detuning load capacitors are external. The
capacitors for fine tuning are integrated. The receive section is using a novel single-conversion/
direct-conversion scheme that is combining the advantages of both receive topologies. The IF is
contained on the chip, no RF channel filters are necessary as the channel filter is also on the chip.
The self-polling logic can be used to let the device operate autonomously as a master for a decoding
microcontroller.
1.2
– Low supply current (I
– Supply voltage range 2.1 V to 5.5 V
– Operating temperature range -40° C to +85° C
– Power down mode with very low supply current consumption
– FSK and ASK modulation and demodulation capability without external circuitry changes, FM
– Fully integrated VCO and PLL synthesizer and loop filter on-chip with on-chip crystal oscillator
– Differential receive signal path completely on-chip, therefore no external filters are necessary
– On-chip low pass channel select and data filter with tuneable bandwith
– Data slicer with self-adjusting threshold and 2 peak detectors
– Self-polling logic with adjustable duty cycle and ultrafast data rate detection and timer mode
– FSK and ASK sensitivity < -109 dBm
– Adjustable LNA gain
– Digital RSSI and Battery Voltage Readout
– Provides Clock Out Pin for external microcontroller
– Transmit power up to +13 dBm in 50W load at 5V supply voltage
– I
Preliminary Specification
voltage, 25°C )
demodulation capability
tuning, therefore no additional external components necessary
providing periodical interrupt
2
C/3-wire microcontroller interface, working at max. 400kbit/s
Product Description
Overview
Features
s
= 9 mA typ. receive, I
s
8
= 13mA typ. transmit mode, both at 3 V supply
Product Description
TDA5251 F1
Version 1.0
2003-02-18
2
C/3-wire