17.05.2015 Views

~ National ~ Semiconductor - Al Kossow's Bitsavers

~ National ~ Semiconductor - Al Kossow's Bitsavers

~ National ~ Semiconductor - Al Kossow's Bitsavers

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

AC Electrical Characteristics<br />

Unless otherwise specified, all specifications apply to the MM74HC942 over the range -40·C to + 85·C using a Vee = +5V<br />

± 10%, a Vss = - 5V ± 10% and a 3.579MHz ± 0.1 % crystal!<br />

Symbol Parameter Conditions Min Typ Max Units<br />

TRANSMITTER<br />

FeE Carrier Frequency Error 4 Hz<br />

Power Output Vee=5.0V l RTLA = 00 -3 -1.5 0 dBm<br />

RL =1.2 kO I RTLA = 5.49 kO -12 -10.5 -9 dBm<br />

2nd Harmonic Energy RTLA = 00 -62 -56 dBm<br />

RECEIVE FILTER AND HYBRID<br />

Hybrid Input Impedance 50 kO<br />

(Pins 15 and 16)<br />

FTLC Output Impedance 5 10 50 kO<br />

Adjacent Channel Rejection RXA2=GND TXA=GND or Vee 60 dB<br />

Input to RXA 1<br />

DEMODULATOR (INCORPORATING HYBRID, RECEIVE FILTER AND DISCRIMINATOR)<br />

Carrier Amplitude -48 -9 dBm<br />

Bit Jitter<br />

SNR = 30dB<br />

Input = -38 dBm<br />

Baud Rate = 300 Baud<br />

}<br />

100 200 ",S<br />

Bit Bias <strong>Al</strong>ternating 1-0 Pattern 5 10 %<br />

Carrier Detect Trip Points CDA=1.2V<br />

I<br />

Ott to On -45 -42 -40 dBm<br />

Vcc=5.0V I On to Ott -47 -45 -42 dBm<br />

Carrier Detect Hysteresis Vee=5V 2 3 4 dB<br />

AC Specification Circuit<br />

SUPPliES Vee= +5V<br />

Vaa= -5V<br />

Vee<br />

TEST<br />

OUTPUT<br />

RTLA<br />

TLA<br />

r-- TXA<br />

~ RXA2<br />

600<br />

3.5795 MHz ± 0.1 %<br />

rD~<br />

MM74HC942<br />

TXD *-DATA INPUT<br />

RXD --+ DATA OUTPUT<br />

600<br />

RXAI<br />

COT CDA FTLC<br />

ru,~<br />

INPUT:<br />

J.., J..01 F J..O.l~F<br />

I O . ,.Fr·<br />

1 ~ J±10%<br />

TLlF/534B-3<br />

5-5

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!