--1--
E99215-TE
Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by
any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the
operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits.
Absolute Maximum Ratings (Ta=25 C)
Supply voltage
V
CC
14
V
Operating temperature
Topr
10 to +60
C
Storage temperature
Tstg
50 to +125
C
Allowable power dissipation
P
D
700
mW
(CXA1691BM)
P
D
1000
mW
(CXA1691BS)
Recommended Operating Conditions
Supply voltage
V
CC
2 to 7.5
V
(CXA1691BM)
V
CC
2 to 8.5
V
(CXA1691BS)
Description
CXA1691BM/BS is a one-chip FM/AM radio IC
designed for radio-cassette tape recorders.
Features
Small number of peripheral components.
Low current consumption (V
CC
=3 V)
For FM : I
D
=5.8 mA (Typ.)
For AM : I
D
=4.7 mA (Typ.)
Built-in FM/AM select switch.
Large output of AF amplifier.
V
CC
=6 V, EIAJ output=500 mW (Typ.)
when load impedance 8
Function
FM section
RF amplifier, Mixer and OSC
(incorporating AFC variable capacitor).
IF amplifier
Quadrature detection
Tuning LED driver
AM section
RF amplifier, Mixer and OSC (with RF AGC)
IF amplifier (with IF AGC)
Detector
Tuning LED driver
AF section
Electronic volume control
FM muting
Structure
Bipolar monolithic IC
FM/AM Radio
CXA1691BM
CXA1691BS
28 pin SOP (Plastic)
30 pin SDIP (Plastic)
CXA1691BM/BS
For the availability of this product, please contact the sales office.
--3--
CXA1691BM/BS
Standard Circuit Design Data
(The pin numbers in the parenthesis are for CXA1691BS.)
Voltage (V)
No.
Symbol
V
CC
=3 V V
CC
=6 V
Equivalent circuit
Description
FM AM FM AM
1
(1, 2)
2 (3)
3 (4)
27 (28)
4 (5)
5 (6)
6 (7)
8 (9)
7 (8)
MUTE
FM DISCRI
NF
AF OUT
VOL CONT
AM OSC
AFC
REG OUT
FM OSC
0
0
0
0
2.18 2.70 4.88 5.43
1.5 1.5 3.0 3.0
1.5 1.5 3.0 3.0
1.25 1.25 1.25 1.25
1.25 1.25 1.25 1.25
1.25
1.25
1.25 1.25 1.25 1.25
1.25 1.25 1.25 1.25
2
1k
1.2k
3
27
V
CC
GND
100
100
4
GND
20k
80k
5
3.6k
6
8
1.25V
(REG)
7
Phase-shift circuit Connect
ceramic discriminator
Negative feedback pin
Power amplifier output pin
Connect variable resistor for
electronic volume control.
AM local oscillation circuit
AFC variable capacitor pin
Regulator pin 1.25 V (Typ.)
FM local oscillation circuit
--4--
CXA1691BM/BS
Voltage (V)
No.
Symbol
V
CC
=3 V V
CC
=6 V
Equivalent circuit
Description
FM AM FM AM
9 (10)
12 (13)
10 (11)
11 (12)
13 (14)
14 (15)
15 (16)
16 (17)
17 (18)
18 (19)
FM RF
FM RF IN
AM RF IN
NC
GND
(FE GND)
FM/AM
FE OUT
BAND
SELECT
AM IF IN
FM IF IN
NC
1.25 1.25 1.25 1.25
0.3
0
0.3
0
1.25 1.25 1.25 1.25
0
0
0
0
0
0
0
0
0.36 0.2 0.36 0.2
0.84
0
0.88
0
0
0
0
0
1.30
0
1.30
0
0
0
0
0
9
3p
8k
1k
12
10
V
CC
AM
FM
220
14
15
GND
V
CC
16
2k
GND
17
360
Connect FM RF tuning coil
FM RF input pin
AM RF input pin
IF output pin of FM and AM.
Connect IF filter.
FM and AM bands selection
switch pin. During GND it
becomes AM and during
open it becomes FM.
Input pin of AM IF.
Input pin of FM IF.
--5--
CXA1691BM/BS
Voltage (V)
No.
Symbol
V
CC
=3 V V
CC
=6 V
Equivalent circuit
Description
FM AM FM AM
19 (20)
20 (21)
21 (22)
22 (23)
23 (24)
24 (25)
25 (26)
26 (27)
28
(29, 30)
METER
GND
AFC/AGC
AFC/AGC
DET OUT
AF IN
RIPPLE
FILTER
V
CC
GND
1.6 1.6 4.5 4.5
0
0
0
0
1.25 1.49 1.25 1.49
1.25 1.25 1.25 1.25
1.25 1.0 1.25 1.0
0
0
0
0
2.71 2.71 5.4 5.4
3.0 3.0 6.0 6.0
0
0
0
0
GND
19
3
N
1.25V
22
21
23
33k 39k
GND
24
11k
4
4
82k
GND
25
17k
73k
90k
V
CC
Meter drive circuit
(For tuning indicator)
AFC pin of W band.
During AM, it determines
time constant of AGC
AFC pin of J band.
During AM, it determines
time constant of AGC.
Detection output pin
Power amplifier input pin
Ripple filter
Power supply pin
Power GND
The pin voltage of pin 6 during AM, it is the same pin voltage of pin 22 (23) during J BAND and is the same
pin voltage of pin 21 (22) during W BAND.
PDF 
ZIP