Micrel

MICRF218

September 2007

3

M9999-090607

(408) 944-0800

16-Pin

QSOP

Pin

Name

Pin Function

10

DO

Demodulated data output.

11

SEL1

Logic control input with active internal pull-up. Used in conjunction with SEL0 to control the

demodulator low pass filter bandwidth. (See filter table for SEL0 and SEL1 in application

subsection)

12

CTH

Demodulation threshold voltage integration capacitor. Capacitor to GND sets the settling time for

the demodulation data slicing level. Values above 1nF are recommended and should be optimized

for data rate and data profile.

13

CAGC

AGC filter capacitor. A capacitor, normally greater than 0.47uF, is connected from this pin to GND

14

RSSI

Received signal strength indication output. Output is from a buffer with 200 ohms typical output

impedance.

15

NC

Not Connected

16

RO2

Reference resonator connection. 7pF in parallel with low resistance MOS switch to GND during

normal operation. Driven by startup excitation circuit during the internal startup control sequence.