T5744-TKS Atmel, T5744-TKS Datasheet - Page 3

• Manufacturer Part Number: T5744-TKS
• Description: RF Transceiver UHF ASK Receiver IC
• Manufacturer: Atmel

Specifications of T5744-TKS

• Operating Supply Voltage: 5 V
• Mounting Style: SMD/SMT
• Package / Case: SSO-20
• Minimum Operating Temperature: - 40 C
• Operating Frequency (max): 450000kHz
• Operating Temperature (min): -40C
• Operating Temperature (max): 105C
• 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

Figure 2-2.
3. RF Front End
4521C–RKE–05/05
Block Diagram
LNAGND
The RF front end of the receiver is a heterodyne configuration that converts the input signal into
a 1-MHz IF signal. According to
fier), LO (Local Oscillator), a mixer and RF amplifier.
The LO generates the carrier frequency for the mixer via a PLL synthesizer. The XTO (crystal
oscillator) generates the reference frequency f
erates the drive voltage frequency f
is divided by factor 64. The divided frequency is compared to f
tor. The current output of the phase frequency detector is connected to a passive loop filter and
thereby generates the control voltage VLF for the VCO. By means of that configuration, VLF is
controlled in a way that f
the following formula:
f
MIXVCC
XTO
LNA_IN
CDEM
AVCC
AGND
DGND
RSSI
= f
LO
/64
LNA
BR_0
and data filter
RSSI IF Amp
Demodulator
4. Order
IF Amp
ASK-
3 MHz
3 MHz
LPF
LPF
BR_1
RSSI
LO
/64 is equal to f
Dem_out
Figure
LO
f
VCO
for the mixer. f
2-2, the front end consists of an LNA (Low-Noise Ampli-
64
XTO
Data interface
. If f
Standby logic
XTO
Test
. The VCO (Voltage-Controlled Oscillator) gen-
LO
XTO
LO
is determined, f
is dependent on the voltage at pin LF. f
XTO
DATA
TEST
MODE
DVCC
ENABLE
LFGND
LFVCC
XTO
LF
by the phase frequency detec-
XTO
can be calculated using
T5744
LO
3