Page 1
Silan
Semiconductors
FM RECEIVER CIRCUIT FOR BATTERY
SC1088
SUPPLY
DESCRIPTION
The SC1088 is a bipolar integrated circuit for use in mono
portable and pocket radios. It is used when a minimum of perpheral
components (of small dimensions and low costs) is important. The
circuit contains a frequency-locked-loop(FLL) system with an
intermediate frequency(IF) of about 70kHz. Selectivity is achieved
by active RC-filters. De-tuning related to the IF and too weak input
signal is suppressed by the mute circuit.
FEATURES
* Equipped with all stages of a mono receiver from antenna to
audio output.
* Mute Circuit
* Search tuning with a single varicap diode
* Mechanical tuning with integrating AFC
* AM application supported
* Power supply polarity protection
* Power supply voltage down to 1.8V
APPLICATION
1. Mechanical tuning: This is possible with or without integrated AFC circuit
2. Electrical tuning: This is realized by one directional(band-up) search tuning facility, including RESET to the
lower-band limit.
SOP-16
PIN CONFIGURATIONS
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
MUTE
OAF
V
LOOP
P
V
OSC
IF FB
LP1
C
V
OIF
1
2
3
4
5
6
7
8
SC1088
1
16
15
14
13
12
11
10
TUNE
C
AP
GND
C
LIM
V
IRF
V
IRF
C
LP2
V
IIF
9
Page 2
Silan
Semiconductors
BLOCK DIAGRAM
SC1088
470pF
3.9nF
180pF
22nF
RUN
0.1µF
330pF
3.3nF
15 3
76 8 9 10 13
VoAF
22kΩ
21
1.8nF
0.1µF
tuning
Fig.1 Block Dirgram and Application Circuit for Search Tuning.
V2
AF
V2
-1
AF
MUTE
V3
&
R
S
Searching
6kΩ
Loop
Filter
Filter
All pass
5.4kΩ
Demodulator
IF Limter
6kΩ
5kΩ
VP
+1
2.2kΩ 2.2kΩ
Mixer
SC1088
V2
VCO
11
82pF
V1
70nH
68pF
5
12
220pF
10kΩ
V101
78nH
4
680pF
10nF
14
+3V
16
68nF
5.6kΩ
RESET
Note: V1,V2 and V3 are internalvoltages.
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
2
Page 3
Silan
Semiconductors
ABSOLUTE MAXIMUM RATINGS
Characteristic Symbol Value Unit
Supply Voltage V
Operating Temperature Tamb -10 ~ +70
Storage Temperature Tstg -55 ~ +150
p
5V
DC ELECTRICAL CHARACTERISTICS
(Tamb=25°C,Vp=3V ,Unless otherwise specified)
Parameter Symbol Test conditions Min Typ Max Unit
Supply Voltage(pin 4) V
Supply Current(Pin 4) I
DC voltage of pin 1 V1 2.50 2.55 2.60 V
DC voltage of pin 3 V3 2.64 2.69 2.74 V
DC voltage of pin 6 and 7 V6,7 2.38 2.44 2.50 V
DC voltage of pin 8 V8 1.60 1.67 1.74 V
DC voltage of pin 9,10 and 13 V9,10,13 2.42 2.47 2.52 V
DC voltage of pin 11 and 12 V11,12 0.91 0.94 0.98 V
DC voltage of pin 15 V15 2.06 2.12 2.18 V
AF output current on pin 2 I2 45 60 80
Oscillator current on pin 5 I5 275 375 500
p
p
1.8 3.0 5.0 V
4.2 5.2 6.6 mA
AC ELECTRICAL CHARACTERISTICS
Tamb=25°C,Vp=3V,Firf=96MHz modulated with ∆f=±22.5kHz and fm=1kHz deviation;EMF=0.3mV(e.m.f. at a
sourse impedance of 75Ω),and measurement taken in fig.3 Unless otherwise specified
Parameter Symbol Test conditions Min Typ Max Unit
V
=-3dB;V
oAF
RF Sensitivityinput voltage
Signal handling
Signal-to -noise ratio (S+N)/N See fig.2
Total Harmonic distortion THD
AM suppression of output
voltage
Ripple rejection RR
Audio output signal Vo(rms)
Vi(rms)
AMS
Vi=1mV;see Fig. 2
Mute OFF 3 6
Mute ON 3 6 12
(S+N)/N=26dB 5 10
THD<10%,∆f=±75kHz
∆f=±22.5kHz
∆f=±75kHz
FM: 1kHz; ±75kHz
AM: 1kHz; MOD=80%
∆Vp=100mVrms,f=1kHz
R
=22kΩ
L
oAF
=0dB at
Search Tuning(with V101 and C16=0.1µF) See Fig.1
Minimum output voltage on pin
16
Tuning steepness
Oscillator steepness
AFC steepness
V16 Limiting point Vp-
∆V/∆t
∆fosc/∆ t
∆I
AFC
Voltage at pin 16 95 210 420 mV/sec
1.25 2.83 5.6 MHz/sec
/∆V3
Voltage at pin 3 4.75 9.5 19
SC1088
°C
°C
µV
µV
µV
200
56
11.4%
2.4 3.3 %
47 52 dB
710 dB
60 85 120 mV
1.85
mV
dB
µs
µA
µA
V
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
3
Page 4
Silan
Semiconductors
PIN DESCRIPTIONS
Pin No. Symbol Description Pin No. Symbol Description
1 MUTE Mute output 9 V
2V
OAF
Audio frequency output
signal
10 C
3 LOOP AF loop filter 11 V
4 Vp Supply voltage 12 V
5 OSC Oscillator resonat circuit 13 C
iIF
LP2
IRF
IRF
LIM
6 IF FB IF feedback 14 GND Ground
7C
8V
LP1
OIF
Low-pass capacitor of 1dB
amplifier
IF output to external coupling
capacitor(high-pass)
15 C
AP
16 TUNE Electrical tuning/AFC output
20
V
OAF
(dB)
0
2
-20
-40
2
1
1
S+N
Noise
SC1088
IF input to limiter amplifier
Low-pass capacitor of IF
limiter amplifier
Radio frequency input
Radio frequency input
Limiter offset voltage
capacitor
All-pass filter capacitor.input
for search tuning
-60
-80
-6
10
1: Mute ON
2: Mute OFF
-5
10
-4
10
-3
10
-2
10
EMF (V)
Fig. 2 Input sensitivity
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
4
Page 5
Silan
Semiconductors
TEST AND APPLICATION CIRCUIT
+3V
Fig. 3 Test circuit and application for mechanical tuning
MUTE
Disable
1516 1314 1112 910
TUNE
CAPGND
MUTE
V
OAF
21 43 65 87
0.1µF
1.8nF
OAF
V
470pF
C
LIMVIRFVIRF
SC1088
V
P
LOOP IF FBOSC
22kΩ
22nF
1.2kΩ
10nF
18pF
C1
0.1µF
220pF
10kΩ
68pF
70nH
78nH
27pF
Rs=75Ω
ViRF
3.3nF
82pF
C
C
EMF
330pF
LP2VIIF
LP1
180pF
SC1088
3,9nF
V
OIF
10kΩ
V
68pF
70nH
iRF
82pF
330pF
3.9nF
470pF
220pF
0.1µF
1516 1314 1112 910
TUNE
CAPGND
C
LIMVIRFVIRF
C
LP2VIIF
SC1088
MUTE
V
OAF
LOOP IF FBOSC
V
P
C
LP1
V
OIF
21 43 65 87
78nH
3.3nF
180pF
27pF
+3V
0.1µF
22kΩ
1.8nF
V
OAF
10nF
68nF
22nF
C2
1.2kΩ
18pF
C1
D1
V101
Fig. 4 Application circuit with AFC for mechanical tuning
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
5
Page 6
Silan
Semiconductors
ON
OFF
switch
Battery
+3V
22µF
earphone
10nF
Transformer
AF
Low
5.1Ω
27kΩ
AF
SC1088
High
Volume
12Ω
Amplifier
33pF
FM
MUTE
47nF
OAF
V
LOOPIF FB OSC
AM
180pF
4.7nF
12pF
22nF
4.7nF
FM
P
V
AM
P
V
LP1
78 56 34 12
C
OIF
V
3.9nF
TUNE
AP
C
GND
LIM
C
IRF
V
SC1088
IRF
V
LP2
C
IIF
V
109 1211 1413 1615
330pF
BAW62
2.7kΩ
470pF
33pF
33pF
10kΩ
UTC7642
AF
1µF
4.7nF
22kΩ
AF
Fig.5 AM application circuit
AM
antenna
1µF
0.1µF
100kΩ
10nF
AM IF
circuit
resonat
Oscillator
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
6
Page 7
Silan
Semiconductors
PACKAGE OUTLINE
SOP-16-225-1.27 UNIT:mm
0.41
SC1088
5.72
1.27
10.20
9.80
6.00
1.95
3.95
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
7
Loading...