Micrel, Inc.
MICRF002/RF022
Operation in this example is at 315MHz, and may be
customized by selection of the appropriate frequency
reference (Y1), and adjustment of the antenna length. The
value of C4 would also change if the optional input filter is
used. Changes from the 1kb/s data rate may require a
change in the value of R1. A bill of materials accompanies
the schematic.
Applications Example
315MHz Receiver/Decoder Application
Figure 7 illustrates a typical application for the MICRF002
UHF Receiver IC. This receiver operates continuously (not
duty cycled) in sweep mode, and features 6-bit address
decoding and two output code bits.
0.4λ monopole
+5V
Supply
Input
antenna (11.6in)
6-bit
address
U1 MICRF002
SSEELL00 SWEN
VSSRF REFOSC
U2 HT-12D
4.8970MHz
Y1
C4
Optional Filter
8.2pF, 16.6nH
pcb foil inductor
1in of 30mil trace
A0
A1
A2
A3
A4
A5
A6
A7
VSS
VDD
VT
R2
1k
R1
L1
VSSRF
ANT
SEL1
CAGC
WAKEB
SHUT
DO
OSC1
OSC2
DIN
68k
4.7µF
VDDRF
VDDBB
CTH
C1
4.7µF
D11
Code Bit 0
Code Bit 1
D10
D9
C2
2.2µF
NC
VSSBB
D8
RF Baseband
(Analog) (Digital)
Ground Ground
Figure 7. 315MHz, 1kbps On-Off Keyed Recwiver/Decoder
Bill of Materials
Item
C1
Part Number
Manufacturer
Vishay(1)
Vishay(1)
Vishay(1)
Vishay(1)
Murata(2)
Lumex(3)
Description
Qty.
1
4.7µF, Dipped Tantalum Capacitor
2.2µF, Dipped Tantalum Capacitor
4.7µF, Dipped Tantalum Capacitor
8.2pF, COG Ceramic Capacitor
6.00MHz, Ceramic Resonator
RED LED
C2
1
C3
1
C4
1
CR1
D1
CSA6.00MG
1
SSF-LX100LID
1
R1
68k, 1/4W, 5%
1
R2
Vishay(1)
Micrel, Inc.(4)
Holtek(5)
1k, 1/4W, 5%
300-440MHz QwikRadio® ASK Receiver
1
U1
MICRF002
1
U2
HT-12D
Logic Decoder
1
Notes:
1. Vishay Tel: (203) 268-6261
2. Murata Tel: (800) 241-6574, Fx: (770) 436-3030
3. Lumex Tel: (800) 278-5666, Fx: (847) 359-8904
5. Micrel, Inc.: (408) 944-0800
5. Holtek Tel: (408) 894-9046, Fx: (408) 894-0838
M9999-070808
July 2008
14
MICREL [ MICREL SEMICONDUCTOR ]
