A Complete FM Radio on a Chip AN192

Performance of the circuit
unless otherwise specified Vp = 4.5 V, Tamb = 25*C, frf= 96 MHz, Vrf = 0.2 mV e.m.f. from a 75 ohm source, modulated with Af - ±22.5 kHz, fm = l kHz. Noise voltage measured unweighted over the bandwidth 300 Hz to 20 kHz

parmeter

typ.

max

unit

sensitivity
	(e.m.f. voltage)
	for -3 dB limiting:
muting disabled
	for -3 dB muting
	for (S+N)IN - 26 dB

signal handling (e.m.f. voltage)
	for THD < 10%; Af - :05 kffl

Signal-to-noise ratio (see Fig.13)

total harmonic distortion (see Fig.13)
	at Af- t22.S kHz
	at Af - t75 kHz

a.m. suppression

	(ratio of the am. output dgrW
	referred to the fm. output signal)
	f.m. aignal: fm - l kHz; Af - t 75 kHz
	X.m. signal: fm - l kHz; m - 80%

ripple rejection (AVp - 100 mV;

	f =( kHz)

oscillator  voltage (r.m.s. value)
	at pin 6

variation of oscillator frequency
	with supply voltage (AVp = l V)

selectivity


a.f.c. range

audio bandwidth at AVo - 3 dB
	measured with pre-emphasis (t = 50 µs)

a.f. output (r.m.s. value)

	at RL - 22 kn

load resistance for audio output current source
	at Vp - 4.5 V
	at vp - 9.0 V

EMF
EMF
EMF


EMF

(S+N)IN


THD
THD








AMS


RR


V6-5(rms)


Afosc

S+300
S-300

Afrf


B


Vo(rms)


RL
RL

1.5 
6
5.5


200

60


0.7 
2.3








50


10


250


60

45
35

±300


10


75


-
-

-
-
-


-

-


-
-








-


-


-


-

-
-

-


-


-


22
47

µV 
µV 
µV 


mv

dB


%
%








dB


dB


mV


kHz/V

dB
dB

kHz


kHz


mv


kOhm
kOhm