TELEFUNKEN Semiconductors
U4240B
AM-Receiver
Description
The U4240B is a bipolar integrated AM receiver circuit.
It performs all the active functions and part of the filtering
required of the AM radio receiver. The device is designed
for car radio and home receiver applications.
Features
D
ESD protected
D
IF output for stereo demodulator and
stop signal generation
D
IF amplifier with gain control
D
Balanced full-wave detector
D
Audio preamplifier
D
Internal AGC voltage
D
Amplifier for field-strength indication
D
Electronic standby ON/ OFF switch
D
D
D
D
AF preamplifier with simple filtering
Controlled RF preamplifier
Double balanced mixer
Separate oscillator with amplitude control
Block Diagram
AM-antenna
tank
17 (19)
16 (17)
AM-oscillator
tank
14 (15)
13 (14) 12 (13)
170
W
Controlled
RF
preamplifier
5 k
W
5 k
W
Internal
supply
voltage
Controlled
oscillator
150
W
11 (12)
10 (11)
50
W
GND
18 (20)
V
S
15 (16)
Indicator
driver
Balanced
mixer
Standby
switch
Controlled
IF amplifier
Balanced
full-wave
detector
AF
amplifier
Control
voltage
amplifier
7 k
W
7 k
W
7 (8)
AM-IF
output
3.5 k
W
12 k
W
1 (1)
2 (2)
IF BPF
3 (4)
4 (5)
( ) SSO 20
5 (6)
6 (7)
8 (9)
9 (11)
93 7715 e
Figure 1.
Rev. A1: 12.07.1995
1 (8)
TEMIC [ TEMIC SEMICONDUCTORS ]
