TDA5210T Infineon Technologies, TDA5210T Datasheet - Page 23
![IC ASK/FSK RECEIVER P-TSSOP-28](/photos/14/17/141745/448-28-tssop-1_sml.jpg)
TDA5210T
Manufacturer Part Number
TDA5210T
Description
IC ASK/FSK RECEIVER P-TSSOP-28
Manufacturer
Infineon Technologies
Datasheet
1.TDA5210.pdf
(53 pages)
Specifications of TDA5210T
Frequency
810MHz ~ 870MHz, 400MHz ~ 440MHz
Sensitivity
-107dBm
Modulation Or Protocol
ASK, FSK
Applications
Alarm Systems, Communication Systems
Current - Receiving
4.8mA
Data Interface
PCB, Surface Mount
Antenna Connector
PCB, Surface Mount
Voltage - Supply
4.6 V ~ 5.5 V
Operating Temperature
-40°C ~ 105°C
Package / Case
28-TSSOP
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
Lead free / RoHS Compliant
Other names
SP000087156
Wireless Components
4.1 Choice of LNA Threshold Voltage and Time Constant
In the following figure the internal circuitry of the LNA automatic gain control is
shown.
Figure 4-1
The LNA automatic gain control circuitry consists of an operational transimped-
ance amplifier that is used to compare the received signal strength signal
(RSSI) generated by the Limiter with an externally provided threshold voltage
U
value between approximately 0.8 and 2.8V to provide a switching point within
the receive signal dynamic range.
This voltage U
can be generated by attaching a voltage divider between the 3VOUT pin
(Pin 24) which provides a temperature stable 3V output generated from the
internal bandgap voltage and the THRES pin. If the RSSI level generated by the
Limiter is higher than U
yields a voltage rise on the TAGC pin (Pin 4). Otherwise, the OTA generates a
negative current. These currents do not have the same values in order to
achieve a fast-attack and slow-release action of the AGC and are used to
charge an external capacitor which finally generates the LNA gain control volt-
age.
thres
. As shown in the following figure the threshold voltage can have any
LNA Automatic Gain Control Circuitry
thres
Pins:
RSSI > U
RSSI < U
is applied to the THRES pin (Pin 23) The threshold voltage
th r es h o ld
th r es h o ld
4 - 2
thres
24
: I
: I
lo a d
lo a d
, the OTA generates a positive current I
20k
=4.2µA
= -1.5µA
+3.1 V
C
4
R1
U
I
C
lo a d
U
U
U
U
c
c
c ma x
c min
:< 2.6V : Gain high
:> 2.6V : Gain low
23
= 1.67V
= V
OTA
C C
U
th re s h old
- 0.7V
Gain control
R2
voltage
VCC
RSSI (0.8 - 2.8V)
LNA
Specification, May 2001
Applications
TDA 5210
load
LNA_autom.wmf
. This