ATA3745P3-TGQY Atmel, ATA3745P3-TGQY Datasheet - Page 8

• Manufacturer Part Number: ATA3745P3-TGQY
• Description: IC UHF ASK/FSK RECEIVER 20SOIC
• Manufacturer: Atmel

Specifications of ATA3745P3-TGQY

• Frequency: 310MHz ~ 440MHz
• Sensitivity: -108dBm
• Data Rate - Maximum: 10 kBaud
• Modulation Or Protocol: ASK, FSK
• Applications: RKE, TPM, Security Systems
• Current - Receiving: 7mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-SOIC (0.300", 7.50mm Width)
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• 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
• Features: -
• Memory Size: -
• Lead Free Status / Rohs Status: Compliant
• Other names: ATA3745P3-TGQYTR

4.4
8
Receiving Characteristics
ATA3745
The cut-off frequency of the low-pass filter is defined by the selected baud rate range
(BR_Range). BR_Range is defined in the OPMODE register (refer to
Receiver” on page
The ATA3745 is designed to operate with data encoding where the DC level of the data signal
is 50%. This is valid for Manchester and Bi-phase encoding. If other modulation schemes are
used, the DC level should always remain within the range of V
V
Each BR_Range is also defined by a minimum and a maximum edge-to-edge time (t
These limits are defined in the section
be exceeded to maintain full sensitivity of the receiver.
The RF receiver ATA3745 can be operated with and without a SAW front end filter. The selec-
tivity with and without a SAW front-end filter is illustrated in
ASK mode of the ATA3745. Note that the mirror frequency is reduced by 40 dB. The plots are
printed relative to the maximum sensitivity. If a SAW filter is used, an insertion loss of about
4 dB must be considered.
When designing the system in terms of receiving bandwidth, the LO deviation must be consid-
ered as it also determines the IF center frequency. The total LO deviation is calculated to be
the sum of the deviation of the crystal and the XTO deviation of the ATA3745. Low-cost crys-
tals are specified to be within ±100 ppm. The XTO deviation of the ATA3745 is an additional
deviation due to the XTO circuit. This deviation is specified to be ±50 ppm. If a crystal of
±100 ppm is used, the total deviation is ±150 ppm in that case. Note that the receiving band-
width and the IF-filter bandwidth are equivalent in ASK mode.
Figure 4-1.
DC_max
= 66%. The sensitivity may be reduced by up to 1.5 dB in that condition.
Receiving Frequency Response
18). BR_Range must be set in accordance to the used baud rate.
-100.0
-20.0
-30.0
-40.0
-60.0
-80.0
-90.0
-50.0
-70.0
-10.0
0.0
-6.0
-5.0 -4.0
-3.0
“Electrical Characteristics” on page
-2.0
-1.0
df (MHz)
0.0
with SAW
1.0
without SAW
2.0
Figure
3.0
4.0
4-1. This example relates to
5.0
“Configuration of the
6.0
23. They should not
D C _ m i n
4901B–RKE–11/07
= 33% and
ee_sig
).