December 2000

3

MICRF007

MICRF007

Micrel

Pin Description

Pin Number

Pin Name

Pin Function

1

VSS

Ground Return (Input): Ground return to the power supply. See “Application

Information” for bypass capacitor details.

2

ANT

Antenna (Input): High-impedance, internally ac coupled receiver input.

Connect this pin to the receive antenna. This FET gate input has approxi-

mately 2pF of shunt (parasitic) capacitance. See “Applications Information”

for optional band-pass filter information.

3

VDD

Power Supply (Input): Positive supply input for the RF IC. Connect a low

ESL, low ESR decoupling capacitor from this pin to VSS, lead lengths

should be as short as possible.

4

CTH

[Data Slicing] Threshold Capacitor (External Component): Capacitor

extracts the dc average value from the demodulated waveform which

becomes the reference for the internal data slicing comparator. See “Appli-

cations Information” for selection.

5

DO

Digital Output (Output): CMOS-level compatible data output signal.

6

SHUT

Shutdown (Input): Shutdown-mode logic-level control input. Pull low to

enable the receiver. This input has an internal pulled-up to VDD.

7

CAGC

AGC Capacitor (External Component): Integrating capacitor for on-chip

AGC (automatic gain control). The decay/attack time-constant (t) ratio is

nominally 10:1. See “Applications Information” for capacitor selection.

8

REFOSC

Reference Oscillator (External Component or Input): Timing reference for

on-chip tuning and alignment. Connect a crystal between this pin and VSS,

or drive the input with an ac-coupled 0.5Vpp input clock.