Rev. 4702H–RKE–09/04
UHF ASK/FSK
Transmitter
ATA5756
ATA5757
Features
PLL Transmitter IC with Single-ended Output
High Output Power (6 dBm) at 8.1 mA (315 MHz) and 8.5 mA (433 MHz) Typical Values
Divide by 24 (ATA5756) and 32 (ATA5757) Blocks for 13 MHz Crystal Frequencies and
for Low XTO Start-up Times
Modulation Scheme ASK/FSK with Internal FSK Switch
Up to 20 kBaud Manchester Coding, Up to 40 kBaud NRZ Coding
Power-down Idle and Power-up Modes to Adjust Corresponding Current Consumption
through ASK/FSK/Enable Input Pins
ENABLE Input for Parallel Usage of Controlling Pins in a 3-wire Bus System
CLK Output Switches ON if the Crystal Current Amplitude has Reached 35% to 80% of
its Final Value
Crystal Oscillator Time Until CLK Output is Activated, Typically 0.6 ms
Supply Voltage 2.0 V to 3.6 V in Operation Temperature Range of -40° C to 125° C
ESD Protection at all Pins (4 kV HBM)
Small Package MSOP10
Benefits
Low Parasitic FSK Switch Integrated
Very Short and Reproducible Time to Transmit Typically < 0.85 ms
13.125 MHz/13.56 MHz Crystals Give Opportunity for Small Package Sizes
Description
The ATA5756/ATA5757 is a PLL transmitter IC which has been developed for the
demands of RF low-cost transmission systems at data rates up to 20 kBaud Manches-
ter coding and 40 kBaud NRZ coding. The transmitting frequency range is 313 MHz to
317 MHz (ATA5756) and 432 MHz to 448 MHz (ATA5757), respectively. It can be used
in both FSK and ASK systems. Due to its shorten crystal oscillator settling time it is
well suited for Tire Pressure Monitoring (TPM) and for Passive Entry Go applications.
Figure 1. System Block Diagram
Demod.
IF Amp
LNA VCO
PLL XTO
Control
U3741B/
U3745B/
T5743/
T5744/
1...3
µC
Power
amp.
XTO VCO
PLL
ATA5756/
ATA5757
Antenna Antenna
UHF ASK/FSK
TPM and Remote control
transmitter
UHF ASK/FSK
Remote control receiver
Encoder
ATARx9x
1 Li cell
Keys