ETC RX3140

RX3140 Low Power IF Receiver IC
the wireless IC company
HiMARK Technology, Inc. reserves the right to change the product described in this datasheet. All information contained 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 incorporates 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
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Extremely low power operation with power-down feature
Built-in crystal oscillator for mixer local oscillator
Mixer input frequency: 10 — 50 MHz
Quadrature detector
On-chip bit-rate filter
Audio output
1-bit comparator with open collector output
1 V regulator
1.1 V low battery alarm
SSOP-20 package (0.65 mm pitch)
Block Diagram
20
19
MIX
IN
VSS
18
REG
OUT
17
REG
CON
16
ALM
15
FSK
OUT
14
LOW
1-BIT
BATTERY COMPARATOR
ALARM
1.0 V
REGULATOR
CHA
RGE
13
12
BS
LPF
OUT
11
LPF
IN
CHARGE/
DISCHARGE
CIRCUIT
MIXER
QUAD
DETECTOR
OSCILLATOR
IFAMP
OSC
OUT
OSC
IN
1
Revision B
2
MIX
OUT
3
VCC
4
IFIN
5
FSK
REF
DEC
6
Page 1
7
IF
OUT
8
AF
OUT
QUAD
9
10
May 2000
RX3140
the wireless IC company
Pin Descriptions
Number
Name
Description
1
OSCIN
2
OSCOUT
Oscillator output (emitter)
3
MIXOUT
Mixer output (2 KΩ output
impedance)
4
VCC
Number
Name
Description
14
CHARGE
Two-state logic input to
control charge-discharge
circuit.
(CHARGE = high = fast
charge; CHARGE = low =
slow charge)
15
FSKOUT
Open collector NRZ comparator output (requires
pull-up resistor)
Oscillator input (base)
Nominal 1.4 V supply
5
IFIN
IF amplifier input (2 KΩ
input impedance)
6
DEC
IF amplifier de-coupling
capacitor connection
16
ALM
Open collector low battery
alarm output (requires pullup resistor)
7
FSKREF
1-bit comparator reference
input (requires external
capacitor)
17
REGCON
1.0 V regulator control output for connection to external PNP base
1.0 V regulator input for
connection to external PNP
collector
8
IFOUT
IF amplifier output
9
QUAD
Quadrature FM demodulator input
18
REGOUT
10
AFOUT
Quadrature FM demodulator output
19
VSS
20
MIXIN
11
LPFIN
LPF operational amplifier
input
12
LPFOUT
LPF operational amplifier
output
13
Revision B
BS
Ground
Mixer input (5 KΩ input
impedance)
Two-state logic input to
control receiver power up/
down.
(BS = high = normal operation; BS = low = stand-by
mode)
Page 2
May 2000
RX3140
the wireless IC company
Absolute Maximum Ratings
VSS = 0 V
Parameter
Symbol
Rating
Unit
Supply voltage
VCC
VSS – 0.3 to VSS + 3.5
V
Operating temperature range
TOPR
–30 to 85
°C
Storage temperature range
TSTG
–55 to 150
°C
Soldering temperature range
TSLD
255
°C
Soldering time range
tSLD
10
s
Recommended Operating Conditions
VSS = 0 V
Value
Parameter
Supply voltage range
Revision B
Symbol
VCC
MIXIN input frequency
fMIXIN
Operating temperature
TA
Page 3
Unit
min.
typ.
max.
1.1
1.35
1.6
V
50
MHz
60
°C
–10
25
May 2000
RX3140
the wireless IC company
Electrical Characteristics
(VCC = 1.4 V, VSS = 0 V, TA = 25 °C, BS = high unless otherwise noted)
Value
Parameter
Symbol
Condition
Unit
min.
Quiescent current consumption
Standby current consumption
Mixer conversion gain
ICC,total
ICC,standby
VBS = 0 V
GC
measured after 455 KHz
ceramic filter
9
typ.
max.
1.1
1.6
mA
5
µA
16
dB
12.5
Mixer output intermodulation intercept point
OIP3
–10
dBm
Mixer input resistance
Rin,MIX
5
KΩ
Mixer output resistance
Rout,MIX
2
KΩ
IF amplifier input resistance
Rin,IF
2
KΩ
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
Low battery alarm threshold voltage
Regulator output voltage
Charging/discharging current
DR
40
50
60
%
VALM
1.05
1.1
1.15
V
VREGOUT
430 Ω load resistor
0.95
1.0
1.05
V
ICH
VFSKREF = 0 V,
VLPFOUT = 0.18 V
35
70
110
µA
ALM logic HIGH output current
IOH,ALM
2
µA
ALM logic LOW output voltage
VOL,ALM
0.4
V
FSKOUT logic HIGH output current
IOH,FSK-
2
µA
FSKOUT logic LOW output voltage
VOL,FSK-
0.4
V
Revision B
OUT
OUT
Page 4
May 2000
RX3140
the wireless IC company
Functional Description
The RX3140 IF receiver IC incorporates a mixer, crystal-based local oscillator, IF amplifier, 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 battery 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 µA. 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/discharging 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 appropriate dc level (i.e. dc level of the LPFOUT pin) and consequently to minimize the erroneous 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 filtered 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 regulation. The external PNP transistor should have an hFE > 200 for VCE ≥ 0.1 V .
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.
Revision B
Page 5
May 2000
RX3140
the wireless IC company
Typical Performance Characteristics
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Revision B
)6.5()9
Page 6
May 2000
RX3140
the wireless IC company
Test Circuit
VREGOUT
19
MIX
IN
VSS
18
REG
OUT
17
REG
CON
16
ALM
15
FSK
OUT
14
LOW
1-BIT
BATTERY COMPARATOR
ALARM
1.0 V
REGULATOR
CHA
RGE
13
12
BS
LPF
OUT
11
68 KΩ
0.01 µF
20
330 pF
68 KΩ
560 pF
68 KΩ
VOD
100 KΩ
100 KΩ
2SA1015GR
430 Ω
2.2 µF
1 nF
VFSKOUT
VCC
51 Ω
VALM
LPF
IN
CHARGE/
DISCHARGE
CIRCUIT
MIXER
QUAD
DETECTOR
OSCILLATOR
IFAMP
4
39 pF
10 µF
22 KΩ
0.1 µF
56 pF
5
6
GC
MURATA
CFVM455E
Revision B
Page 7
7
8
22 pF
AF
OUT
QUAD
9
10
3.3 KΩ
3
IF
OUT
FSK
REF
DEC
10 µF
2
IFIN
10 µF
1
VCC
VCC
VCC
MIX
OUT
0.1 µF
OSC
OUT
OSC
IN
VCC
May 2000
RX3140
the wireless IC company
Application Circuit
LNA
1st mixer
OSCIN
1st IF
amplifier
MIXIN
OSCOUT
VSS
MIXOUT
REGOUT
IFIN
DEC
FSKREF
IFOUT
Frequency
multiplier (×2,3)
QUAD
+07
VCC
REGCON
ALM
FSKOUT
CHARGE
BS
LPFOUT
AFOUT
LPFIN
1st LO
XIN
TEST
XOUT
DB
DO
VSS
FIN
+07
VDD2
RAM
ROM
CPU
Decoder
NC
VDD1
OPR
LE
DATA
CLK
LD
NC
LCD driver
Driver
LCD
DC/DC
converter
Revision B
Page 8
May 2000