U3741BM Datasheet, PDF (1/25 Pages) ATMEL Corporation – UHF ASK RECEIVER IC

UHF ASK/FSK Receiver
U3741BM
Description
The U3741BM is a multi-chip PLL receiver device
supplied in an SO20 package. It has been specially
developed for the demands of RF low-cost data
transmission systems with low data rates from 1 kBaud to
10 kBaud (1 kBaud to 3.2 kBaud for FSK) in Manchester
or Bi-phase code. The receiver is well suited to operate
with the TEMIC PLL RF transmitter U2741B. Its main
applications are in the areas of telemetering, security
technology and keyless-entry systems. It can be used in
the frequency receiving range of f₀ = 300 MHz to
450 MHz for ASK or FSK data transmission. All the
statements made below refer to 433.92-MHz and
315-MHz applications.
Features
D Minimal external circuitry requirements, no RF
components on the PC board except adaptation to the
receiver antenna
D High sensitivity, especially at low data rates
D Sensitivity reduction possible even while receiving
D Fully integrated VCO
D Low power consumption due to configurable self
polling with a programmable timeframe check
D Supply voltage 4.5 V to 5.5 V,
operating temperature range –40°C to 105°C
D Single-ended RF input for easy adaptation to
l/4 antenna or printed antenna on PCB
D Low-cost solution due to high integration level
D ESD protection according to MIL-STD. 883
(4KV HBM) except Pin POUT (2KV HBM)
D High image frequency suppression due to 1 MHz IF
in conjunction with a SAW front-end filter. Up to
40 dB is thereby achievable with newer SAWs.
D Programmable output port for sensitivity selection or
for controlling external periphery
D Communication to mC possible via a single,
bi-directional data line
D Power management (polling) is also possible by
means of a separate pin via the mC
D 2 different IF bandwidth versions are available
(300 kHz and 600 kHz)
System Block Diagram
1 Li cell
Encoder
Keys ^M44Cx9x
UHF ASK/FSK
Remote control transmitter
U2741B
UHF ASK/FSK
Remote control receiver
U3741BM
Demod.
Control
XTO
PLL
VCO
Antenna Antenna
IF Amp
PLL
XTO
1...3 _mC
Power
amp.
LNA
VCO
14917
Figure 1. System block diagram
Rev. A1, 15-Oct-98
1 (25)
Preliminary Information