Philips Semiconductors
FM/IF amplifier/demodulator circuit
Product specification
TDA1576T
CHARACTERISTICS
VP = 8.5 V; fIF = 10.7 MHz; RS = 60 Ω; fm = 400 Hz with ∆f = ±22.5 kHz; 50 µs de-emphasis (C8-9 = 6.8 nF);
Tamb = 25 °C and measurements taken in Fig.1; unless otherwise specified. The demodulator circuit is adjusted at
minimum second harmonic distortion for ViIF = 1 mV and a deviation ∆f = ±75 kHz.
SYMBOL
PARAMETER
CONDITIONS
MIN. TYP. MAX. UNIT
VP
supply voltage (pin 1)
IP
supply current
Reference voltage
Vref
∆Vref
reference voltage (pin 14)
reference voltage dependence on
temperature
I14
maximum output current
R14
output resistor -∆-∆--V-I--1-1--4-4-
V5 = V9 = V13 = 0
7.5
8.5
15
V
10
16
23
mA
I14 = −1 mA
−
V-----1∆--4--V--×--1---4∆----T--
−
short-circuit current
4
I14 < 1.2 mA
−
4.9
−
V
0.3
−
%/K
6
7.5
mA
60
150 Ω
IF amplifier
ViIF(rms)
R17-18
C17-18
VoIF(p-p)
input sensitivity (RMS value; pin 17)
input resistance
input capacitance
output voltage at pins 3 and 7
(peak-to-peak value)
R3-7
output resistance
Demodulator
R4-6
C4-6
R8, 9
V8, 9
∆-∆---Vϕ---
input resistance
input capacitance
output resistance
DC offset voltage on output pins at
V4-6 = 0
demodulator efficiency
demodulator efficiency dependent on
supply voltage
V/V
DC voltage ratio
∆-∆---VT---
dependence on temperature
−3 dB before limiting 14
22
35
µV
ViIF = 200 mV (RMS) 10
−
−
kΩ
ViIF = 200 mV (RMS) −
5
−
pF
Z3, 7 = 10 pF parallel to 610
680
750
mV
1 MΩ
200 250 300 Ω
V5 > 3 V or V3-7 = 0 or
V13 < 0.3 V
∆----∆V----ϕ8-----9-
-∆---ϕ-----(---V----PV----8-–----9-3----V----B---E----)-
V-----82----+V----2-V----9-
∆-----V---------8∆2-------T-+V--------2-V---------9--
20
−
2.9
−
−
−
0.653
−
30
1
3.7
0
40
6.2
0.667
10−5
40
2.5
4.5
±100
−
−
0.680
−
kΩ
pF
kΩ
mV
mV/°
mV/°
V/V
1/K
1998 Nov 18
6