mc13176d ETC-unknow, mc13176d Datasheet - Page 14

• Manufacturer Part Number: mc13176d
• Description: Fm/am Transmitter
• Manufacturer: ETC-unknow

– 5.0
– 20
– 25
14
–10
–15
Figure 28. Power Output versus Modulation Current
5.0
10
0
0.1
I mod , MODULATION CURRENT (mA)
On–Off Keying Encoded
10 kHz TTL Waveform
OOK Input Modulation
Oscillator Waveform
Carrier Envelope
1.0
Pin 16
V CC = 3.0 Vdc
f = 320 MHz
Pin 8
Figure 26. ASK Input Waveform and Modulated Carrier
Figure 27. Oscillator Enable Time, T enable
MC13175 MC13176
10
Analog AM
must be carefully considered. Figure 28 is a plot of Power
Output versus Modulation Current at 320 MHz, 3.0 Vdc. In
order to achieve a linear encoding of the modulating
sinusoidal waveform on the carrier, the modulating signal
must amplitude modulate the carrier in the linear portion of its
power output response. When using a sinewave modulating
signal, the signal rides on a positive DC offset called V mod
which sets a static (modulation off) modulation current, I mod .
I mod controls the power output of the IC. As the modulating
signal moves around this static bias point the modulating
current varies causing power output to vary or to be AM
modulated. When the IC is operated at modulation current
levels greater than 2.0 mAdc the differential output stage
starts to saturate.
In analog AM applications, the output amplifier’s linearity
MOTOROLA RF/IF DEVICE DATA