FM IF RECEIVER
S1T8513A
1
INTRODUCTION
The S1T8513A is designed for FM IF Detection on the pager set. It
includes a voltage regulator, low battery detection circuit, Mixer,
Oscillator, FSK comparator and limiting IF Amplifier.
FEATURES
Operating voltage range: 1.0 to 4.0V
Typical supply current: 1.1mA at 1.4V
Low battery detection circuit (alarm function): 1.05V
Voltage regulator : Vreg = 1.0V (Typ.)
Mixer operating frequency: 10 to 50MHz
High transmitting rate: 1200 / 2400bps
FSK Data reception
Package type: 20-SSOP (0.65mm)
ORDERING INFORMATION
BLOCK DIAGRAM
Device
Package
Operating Temperature
S1T8513A02-V0B0
20-SSOP-225
-
20
C to +70
C
20
-
SSOP
-
225
20
19
18
17
16
15
14
13
12
11
1
2
3
4
5
6
7
8
9
10
2'nd
MIX
X-tal
Osc
1.0V Reg
Alarm
Limiting IF
Amplifier
Quick
Charge
Quad
Detector
MI
GND
REGO REGC
AO
FSKO
QC
BSC
LPFO
LPFI
OSCI
OSCO
MO
Vcc
LI
LD
FSKI
IFO
QD
RAO
filter AMP
audio AMP
FSK
COMP.
FM IF RECEIVER
S1T8513A
3
PIN DESCRIPTION
ABSOLUTE MAXIMUM RATINGS
Pin No
Symbol
Description
1
OSCI
Oscillator input. The oscillator is an internally-biased colpitts type.
2
OSCO
Oscillator output.
3
MO
Mixer output pin. Output impedance
2k
.
Connect a 455kHz filter between this pin and the LI.
4
V
CC
V
CC
pin.
5
LI
IF limiter amplifier input. Input impedance 2k
.
6
LD
Bypass capacitor connect pin for the IF limiter amplifier.
7
FSKI
Differential Amp. reference input on the FSK comparator.
8
IFO
IF Amp output.
9
QD
Quadrature detection, phase shifter pin.
10
RAO
Recovered audio signal output.
11
LPFI
Low pass filter amplifier input. Bias is supplied from pin 10.
12
LPFO
Low pass filter amplifier output.
13
BSC
Battery saving control pin.
High: Battery saving off. Low: Battery saving on
14
QC
Quick charge control pin.
High: Quick charge-discharge on. Low: Quick charge-discharge off.
15
FSKO
FSK signal output pin.
16
AO
Alarm output. This pin becomes High when V
CC
drops below 1.05V.
17
REGC
S1T8513A has an internal PNP transistor.
But, it also can support an external PNP transistor to control the power.
18
REGO
Regulated voltage output.
19
GND
Ground.
20
MI
Mixer input impedance
5k
.
Characteristic
Symbol
Value
Unit
Max. Supply Voltage
V
CC (MAX)
4
V
Power Dissipation
P
D
800
mW
Operating Temperature
T
OPR
-
20 to +70
C
Storage Temperature
T
STG
-
55 to +125
C
S1T8513A
FM IF RECEIVER
4
ELECTRICAL CHARACTERISTICS
(V
CC
= 1.4V
5%, f
IN
(2MIX)
= 21.4MHz, f
DEV
=
4.8kHz, f
MOD
= 600Hz, Ta = 25
C, unless otherwise specified)
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Unit
Operating current
I
CCN
No Input Signal
-
1.1
1.6
mA
I
CCS
Battery Saving
-
0
10
A
Alarm Detection Voltage
V
AD
-
1.0
1.05
1.1
V
Alarm Low Level Output Voltage
V
O (AL)
I = 100
A
-
-
0.4
V
Alarm High Level Leakage Current
I
LKG (AL)
-
-
-
2
A
FSK Low Level Output Voltage
V
L (FSK)
I = 100
A
-
-
0.4
V
FSK High Level Leakage Current
I
LKG (FSK)
-
-
-
2
A
Regulator Output Voltage
V
O (REG)
-
0.95
1.0
1.05
V
Quick Charge Current
I
C
-
50
70
-
A
Input for
-
3dB Sensitivity
V
LIM
Mixer Input
-
2.5
7.5
Vrms
Input for
-
12dB SINAD Sensitivity
V
I (SEN)
IF Input
-
6.0
18.0
Vrms
Recovered Audio Output Voltage
V
O (RAO)
V
IN (2MIX)
= 500
Vrms
37
55
73
mVrms
Mixer Conversion Voltage Gain
G
V (M)
Ceramic Filter loss =
-
1dB
8
12
16
dB
Signal to Noise Ratio
S/N
V
IN (2MIX)
= 500
Vrms
38
55
-
dB
Total Harmonic Distortion
THD
V
IN (2MIX)
= 500
Vrms
-
2.0
3.5
%
Mixer 3rd Order Intercept Point
3RD
-
-
-
10
-
dBm
Mixer Input Resistance
R
I (MIX)
-
3.5
5
6.5
k
Limiting Amplifier Input Resistance
R
I (LA)
-
1.4
2
2.6
k
AM Rejection Ratio
AMR
V
IN (2MIX)
= 5
Vrms
(AM = 300%)
25
40
-
dB
Data Shaping Output Duty Ratio
DR
V
IN (2MIX)
= 500
Vrms
40
50
60
%
PDF 
ZIP
