MICRF002/RF022

Micrel

MICRF002/RF022

14

March 2003

Applications Example

315MHz Receiver/Decoder Application

Figure 7a 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.

Operation in this example is at 315MHz, and may be custom-

ized 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.

SEL0

SEL0

SWEN

VSSRF

REFOSC

VSSRF

SEL1

ANT

CAGC

VDDRF

WAKEB

VDDBB

SHUT

CTH

DO

NC

VSSBB

C2

2.2

µF

4.8970MHz

Y1

U1 MICRF002

4.7

µF

Optional Filter

8.2pF, 16.6nH

pcb foil inductor

1in of 30mil trace

C4

L1

+5V

Supply

Input

C1

4.7

µF

A0

VDD

A1

VT

A2

OSC1

A3

OSC2

A4

DIN

A5

D11

A6

D10

A7

D9

U2 HT-12D

VSS

D8

R1

68k

R2

1k

Code Bit 0

Code Bit 1

RF

(Analog)

Ground

Baseband

(Digital)

Ground

0.4

monopole

antenna (11.6in)

6-bit

address

Figure 7a. 315MHz, 1kbps On-Off Keyed Receiver/Decoder

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Figure 7c. Component Vendors