TDA7210 Infineon Technologies, TDA7210 Datasheet - Page 24

• Manufacturer Part Number: TDA7210
• Description: IC RECEIVER FSK/ASK 28-TSSOP
• Manufacturer: Infineon Technologies
• Type: ASK/FSK Single Conversion Receiverr

Specifications of TDA7210

• Package / Case: 28-TSSOP
• Frequency: 810MHz ~ 870MHz, 400MHz ~ 440MHz
• Sensitivity: -110dBm
• Data Rate - Maximum: 100 kbps
• Modulation Or Protocol: ASK, FSK
• Applications: Remote Control, RKE, Security Systems
• Current - Receiving: 5.9mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Operating Supply Voltage: 5 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Supply Current: 7.7 mA
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4.5 V
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (max): 5.5V
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 28
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Memory Size: -
• Lead Free Status / Rohs Status: Compliant
• Other names: SP000524274; TDA7210; TDA7210INTR

Wireless Components
Figure 4-2
The switching point should be chosen according to the intended operating sce-
nario. The determination of the optimum point is described in the accompanying
Application Note, a threshold voltage level of 1.8V is apparently a viable choice.
It should be noted that the output of the 3VOUT pin is capable of driving up to
50µA, but that the THRES pin input current is only in the region of 40nA. As the
current drawn out of the 3VOUT pin is directly related to the receiver power con-
sumption, the power divider resistors should have high impedance values. The
sum of R1 and R2 has to be 600kΩ in order to yield 3V at the 3VOUT pin. R1
can thus be chosen as 240kΩ, R2 as 360kΩ to yield an overall 3VOUT output
current of 5µA
Note: If the LNA gain shall be kept in either high or low gain mode this has to
be accomplished by tying the THRES pin to a fixed voltage. In order to achieve
always high gain mode operation, a voltage higher than 3.3V shall be applied
to the THRES pin. A short to the 3VOLT pin will keep the LNA in high gain mode
at least over a large RF-input level range. But to switch the LNA reliable into
high gain mode over the whole RF-input level range, either a voltage higher
than 3.3V has to be applied on pin 23 as mentioned above or, as alternative, a
330k resistor in parallel with a 47nF capacitor can be connected between pin 4
and GND. Whereas the capacitor should be placed as close as possible to pin
4. In order to achieve low gain mode operation a voltage lower than 0.7V shall
be applied to the THRES, such as a short to ground.
As stated above the capacitor connected to the TAGC pin is generating the gain
control voltage of the LNA due to the charging and discharging currents of the
OTA and thus is also responsible for the AGC time constant. As the charging
and discharging currents are not equal two different time constants will result.
The time constant corresponding to the charging process of the capacitor shall
be chosen according to the data rate. According to measurements performed
at Infineon the capacitor value should be greater than 47nF.
2.5
1.5
0.5
1. note the 20kΩ resistor in series with the 3.1V internal voltage source
3
2
1
0
-120
-110
RSSI Level and Permissive AGC Threshold Levels
1
and a threshold voltage of 1.8V
-100
RSSI Level
4 - 3
-90
Input Level at LNA Input [dBm]
-80
-70
-60
Data Sheet, December 2008
-50
-40
Applications
TDA7210
-30
RSSI-AGC.wmf