Revision B
Page 1
May 2000
RX3140 Low Power IF Receiver IC
HiMARK Technology, Inc. reserves the right to change the product described in this datasheet. All information con-
tained in this datasheet is subject to change without prior notice. HiMARK Technology, Inc. assumes no responsibility
for the use of any circuits shown in this datasheet.
Description
The RX3140 is a low power IF receiver IC which is fully compatible with the Toshiba
TA31142 IC and is suitable for use as the second IF downconverter in double-conversion
paging systems. The RX3140 is well-suited for POCSAG paging applications and incor-
porates a 2-level FSK demodulator consisting of a quadrature FM demodulator, on-chip
bit-rate filter, and 1-bit comparator. An on-chip 1 V regulator is provided for convenient
biasing of off-chip circuitry.
Features
u Extremely low power operation with power-down feature
u Built-in crystal oscillator for mixer local oscillator
u Mixer input frequency: 10 -- 50 MHz
u Quadrature detector
u On-chip bit-rate filter
u Audio output
u 1-bit comparator with open collector output
u 1 V regulator
u 1.1 V low battery alarm
u SSOP-20 package (0.65 mm pitch)
Block Diagram
the wireless IC company
1.0 V
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
QUAD
MIX
IN
VSS
REG
OUT
REG
CON
ALM
FSK
OUT
CHA
RGE
LPF
OUT
BS
LPF
IN
OSC
IN
OSC
OUT
MIX
OUT
IFIN
VCC
DEC
FSK
REF
LOW
BATTERY
ALARM
1-BIT
COMPARATOR
CHARGE/
DISCHARGE
CIRCUIT
IFAMP
QUAD
DETECTOR
MIXER
OSCILLATOR
REGULATOR
AF
OUT
IF
OUT
RX3140
the wireless IC company
Revision B
Page 2
May 2000
Pin Descriptions
Number
Name
Description
1
OSCIN
Oscillator input (base)
2
OSCOUT
Oscillator output (emitter)
3
MIXOUT
Mixer output (2 K
output
impedance)
4
VCC
Nominal 1.4 V supply
5
IFIN
IF amplifier input (2 K
input impedance)
6
DEC
IF amplifier de-coupling
capacitor connection
7
FSKREF
1-bit comparator reference
input (requires external
capacitor)
8
IFOUT
IF amplifier output
9
QUAD
Quadrature FM demodula-
tor input
10
AFOUT
Quadrature FM demodula-
tor output
11
LPFIN
LPF operational amplifier
input
12
LPFOUT
LPF operational amplifier
output
13
BS
Two-state logic input to
control receiver power up/
down.
(BS = high = normal opera-
tion; BS = low = stand-by
mode)
14
CHARGE
Two-state logic input to
control charge-discharge
circuit.
(CHARGE = high = fast
charge; CHARGE = low =
slow charge)
15
FSKOUT
Open collector NRZ com-
parator output (requires
pull-up resistor)
16
ALM
Open collector low battery
alarm output (requires pull-
up resistor)
17
REGCON
1.0 V regulator control out-
put for connection to exter-
nal PNP base
18
REGOUT
1.0 V regulator input for
connection to external PNP
collector
19
VSS
Ground
20
MIXIN
Mixer input (5 K
input
impedance)
Number
Name
Description
RX3140
the wireless IC company
Revision B
Page 3
May 2000
Absolute Maximum Ratings
V
SS
= 0 V
Recommended Operating Conditions
V
SS
= 0 V
Parameter
Symbol
Rating
Unit
Supply voltage
V
CC
V
SS
0.3 to V
SS
+ 3.5
V
Operating temperature range
T
OPR
30 to 85
C
Storage temperature range
T
STG
55 to 150
C
Soldering temperature range
T
SLD
255
C
Soldering time range
t
SLD
10
s
Parameter
Symbol
Value
Unit
min.
typ.
max.
Supply voltage range
V
CC
1.1
1.35
1.6
V
MIXIN input frequency
f
MIXIN
50
MHz
Operating temperature
T
A
10
25
60
C
RX3140
the wireless IC company
Revision B
Page 4
May 2000
Electrical Characteristics
(V
CC
= 1.4 V, V
SS
= 0 V, T
A
= 25 C, BS = high unless otherwise noted)
Parameter
Symbol
Condition
Value
Unit
min.
typ.
max.
Quiescent current consumption
I
CC,total
1.1
1.6
mA
Standby current consumption
I
CC,standby
V
BS
= 0 V
5
A
Mixer conversion gain
G
C
measured after 455 KHz
ceramic filter
9
12.5
16
dB
Mixer output intermodulation intercept point
OIP3
10
dBm
Mixer input resistance
R
in,MIX
5
K
Mixer output resistance
R
out,MIX
2
K
IF amplifier input resistance
R
in,IF
2
K
S/N ratio 1
SN1
53 dBm at MIXIN
63
dB
S/N ratio 2
SN2
53 dBm at IFIN
63
dB
S/N ratio 3
SN3
91 dBm at IFIN
25
dB
Demodulation output level
VOD
53 dBm at IFIN
45
mVrms
AM rejection ratio
AMR
53 dBm at IFIN,
AM=30 %
50
dB
FSK output duty ratio
DR
40
50
60
%
Low battery alarm threshold voltage
V
ALM
1.05
1.1
1.15
V
Regulator output voltage
V
REGOUT
430
load resistor
0.95
1.0
1.05
V
Charging/discharging current
I
CH
V
FSKREF
= 0 V,
V
LPFOUT
= 0.18 V
35
70
110
A
ALM logic HIGH output current
I
OH,ALM
2
A
ALM logic LOW output voltage
V
OL,ALM
0.4
V
FSKOUT logic HIGH output current
I
OH,FSK-
OUT
2
A
FSKOUT logic LOW output voltage
V
OL,FSK-
OUT
0.4
V
RX3140
the wireless IC company
Revision B
Page 5
May 2000
Functional Description
The RX3140 IF receiver IC incorporates a mixer, crystal-based local oscillator, IF ampli-
fier, quadrature FM demodulator, bit-rate filter, and 1-bit comparator and is capable of
demodulating 2-level FSK input signals. In addition, 1.0 V regulator and 1.1 V low bat-
tery alarm functions are provided.
Power-down Function
The entire receiver IC may be powered up and down through the control of the BS input
(pin 13). During power down operation, the quiescent current consumption of the IC
drops to approximately 0
A. The high input impedance of the BS pin allows for direct
interfacing with the CMOS output of an off-chip microcontroller.
Charge/Discharge Circuitry
The function of the charge/discharge circuitry is for both fast and slow charging/discharg-
ing of the capacitor used for storing the voltage reference level of the FSKREF pin. The
CHARGE input (pin 14) should be enabled (CHARGE = high = fast charge) immediately
after transition of the receiver IC from power-down to normal operation in order to reduce
the charging/discharging time for coarse adjustment of the FSKREF voltage to the appro-
priate dc level (i.e. dc level of the LPFOUT pin) and consequently to minimize the errone-
ous output of the 1-bit comparator. During actual data reception, the CHARGE pin should
be set to low (CHARGE = low = slow charge) for fine adjustment of the FSKREF voltage.
1-bit Comparator
The integrated 1-bit comparator operates as a data slicer and "squares up" the bit-rate fil-
tered output from the quadrature demodulator. The decision threshold voltage level for
the 1-bit comparator is stored on an external capacitor connected to the FSKREF pin.
Regulator
The on-chip 1.0 V regulator requires a suitable off-chip PNP transistor to achieve regula-
tion. The external PNP transistor should have an h
FE
> 200 for
.
Low Battery Alarm
The low battery alarm output, ALM, is normally low, but rises to 1.1 V (
VCC) when the
VCC voltage falls below approximately 1.1 V.
V
CE
0.1 V
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