TDA5211XT Infineon Technologies, TDA5211XT Datasheet - Page 20

• Manufacturer Part Number: TDA5211XT
• Manufacturer: Infineon Technologies

Specifications of TDA5211XT

• Operating Temperature (min): -40C
• Operating Temperature Classification: Automotive
• Product Depth (mm): 4.4mm
• Product Length (mm): 9.7mm
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Lead Free Status / Rohs Status: Compliant

Wireless Components
3.4.10
3.4.7
3.4.8
3.4.9
The demodulator circuit is switched off in case of reception of ASK signals.
Data Filter
The data filter comprises an OP-Amp with a bandwidth of 100kHz used as a
voltage follower and two 100k
capacitors a 2nd order Sallen-Key low pass filter is formed. The selection of the
capacitor values is described in Section 4.2.
Data Slicer
The data slicer is a fast comparator with a bandwidth of 100 kHz. This allows
for a maximum receive data rate of up to 100kBaud. The maximum achievable
data rate also depends on the IF Filter bandwidth and the local oscillator toler-
ance values. Both inputs are accessible. The output delivers a digital data sig-
nal (CMOS-like levels) for sbsequent circuits. The self-adjusting threshold on
pin 20 its generated by RC-term or peak detector depending on the baseband
coding scheme. The data slicer threshold generation alternatives are described
in more detail in Section 4.5.
Peak Detector
The peak detector generates a DC voltage which is proportional to the peak
value of the receive data signal. An external RC network is necessary. The input
is connected to the output of the RSSI-output of the Limiter, the output is con-
nected to the PDO pin (Pin 26 ). This output can be used as an indicator for the
received signal strength to use in wake-up circuits and as a reference for the
data slicer in ASK mode. The output current is typically 950µA, the discharge
current is lower than 2µA. Note that the RSSI level is also output in case of FSK
mode.
Bandgap Reference Circuitry
A Bandgap Reference Circuit provides a temperature stable reference voltage
for the device. A power down mode is available to switch off all subcircuits which
is controlled by the PWDN pin (Pin 27) as shown in the following table. The sup-
ply current drawn in this case is typically 50nA.
Table 3-4 PDWN Pin Operating States
PDWN
Open or tied to ground
Tied to Vs
3 - 12
on-chip resistors. Along with two external
Powerdown Mode
Operating State
Receiver On
Functional Description
Specification, May 2001
TDA 5211