TDA7210 Infineon Technologies, TDA7210 Datasheet - Page 32

• 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
4.7 Principle of the Precharge Circuit
In case the data slicer threshold shall be generated with an external RC network
as described in Section 4.5 it is necessary to use large values for the capacitor
C13 attached to the SLN pin (pin 20) in order to achieve long time constants.
This results also from the fact that the choice of the value for R1 connected
between the SLP and SLN pins (pins 19 and 20) is limited by the 330k Ω resistor
appearing in parallel to R1 as can be seen in Figure 4-7. Apart from this a resis-
tor value of 100k Ω leads to a voltage offset of 1mV at the comparator input as
described in Section 4.6.1. The resulting startup time constant τ
lated with:
In case R1 is chosen to be 100k Ω and C13 is chosen as 47nF this leads to
When the device is turned on this time constant dominates the time necessary
for the device to be able to demodulate data properly. In the powerdown mode
the capacitor is only discharged by leakage currents.
In order to reduce the turn-on time in the presence of large values of C13 a pre-
charge circuit was included in the TDA7210 as shown in the following figure.
Figure 4-10
20k
24
Principle of the precharge circuit
U2
τ
+3.1V
1
R4
R4+R5=600k
=
23
(
Uc>Us
C18
100
U
threshold
-
4 - 11
OTA
k
R5
Ω
0 / 240uA
Uc<Us
τ
||
+2.4V
1
330
U2<2.4V : I=240uA
U2>2.4V : I=0
=
k
I
load
(
Ω
R
)
1
×
-
+
||
20
47
330
nF
Uc
C13
R1
k
=
Ω
19
77
Us
)
k
×
Ω
C
Data Filter
×
13
47
Data Sheet, December 2008
nF
=
ASK/FSK Switch
3
6 .
ms
1
Applications
can be calcu-
TDA7210
precharge.WMF