PTC RX3140

RX3140 Low Power IF Receiver IC
Princeton Technology Corp. reserves the right to change the product described in this datasheet. All information contained in this datasheet is subject to change without prior notice. Princeton Technology Corp. 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
‹
‹
‹
‹
‹
‹
‹
‹
‹
‹
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
TSSOP-20 package (0.65 mm pitch)
Applications
‹ Pager
‹ Wireless mouse
‹ Two-way car alarm system
Block Diagram
20
MIX
IN
19
VSS
18
REG
OUT
17
REG
CON
1.0 V
REGULATOR
16
15
ALM
FSK
OUT
14
CHA
RGE
LOW
1-BIT
BATTERY COMPARATOR
ALARM
13
12
BS
LPF
OUT
11
LPF
IN
CHARGE/
DISCHARGE
CIRCUIT
MIXER
DETECTOR
QUAD
OSCILLATOR
IFAMP
1
OSC
IN
2
OSC
OUT
3
MIX
OUT
4
VCC
5
IFIN
6
DEC
7
FSK
REF
8
IF
OUT
Page 1
For:Natertech
AF
OUT
QUAD
9
10
April 2003
RX3140
Package and Pin Assignment: 20L, TSSOP
OSCIN
MIXIN
MIXOUT
VCC
IFIN
DEC
Date Code
FSKREF
IFOUT
QUAD
AFOUT
Dimensions in mm
Symbols
HiMARK
RX3140
OSCOUT
VSS
REGOUT
REGCON
ALM
FSKOUT
CHARGE
BS
LPFOUT
LPFIN
Dimensions in inch
MIN.
NOM.
MAX.
MIN.
NOM.
MAX.
A
---
---
1.20
---
---
0.048
A1
0.05
---
0.15
0.002
---
0.006
A2
0.80
1.00
1.05
0.031
0.039
0.041
b
0.19
---
0.30
0.007
---
0.012
C
0.09
---
0.20
0.004
---
0.008
D
6.40
6.50
6.60
0.252
0.256
0.260
E
---
6.40
---
---
0.252
---
E1
4.30
4.40
4.50
0.169
0.173
0.177
e
---
0.65
---
---
0.026
---
L
0.45
0.60
0.75
0.018
0.024
0.030
y
---
---
0.10
---
---
0.004
θ
0°
---
8°
0°
---
8°
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For:Natertech
April 2003
RX3140
Pin Descriptions
Number
Name
I/O
Description
1
OSCIN
I
Oscillator input (base)
2
OSCOUT
O
Oscillator output (emitter)
3
MIXOUT
O
Mixer output (2 KΩ output impedance)
4
VCC
POWER
5
IFIN
I
IF amplifier input (2 KΩ input impedance)
6
DEC
I
IF amplifier de-coupling capacitor connection
7
FSKREF
I
1-bit comparator reference input (requires external capacitor)
8
IFOUT
O
IF amplifier output
9
QUAD
I
Quadrature FM demodulator input
10
AFOUT
O
Quadrature FM demodulator output
11
LPFIN
I
LPF operational amplifier input
12
LPFOUT
O
LPF operational amplifier output
13
BS
I
Two-state logic input to control receiver power up/down.
(BS = high = normal operation; BS = low = stand-by mode)
14
CHARGE
I
Two-state logic input to control charge-discharge circuit.
(CHARGE = high = fast charge; CHARGE = low = slow charge)
15
FSKOUT
O
Open collector NRZ comparator output (requires pull-up resistor)
16
ALM
O
Open collector low battery alarm output (requires pull-up resistor)
17
REGCON
O
1.0 V regulator control output for connection to external PNP base
18
REGOUT
I
1.0 V regulator input for connection to external PNP collector
19
VSS
GND
20
MIXIN
I
Nominal 1.4 V supply
Ground
Mixer input (5 KΩ input impedance)
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For:Natertech
April 2003
RX3140
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
Parameter
Supply voltage range
Symbol
VCC
MIXIN input frequency
fMIXIN
Operating temperature
TA
Value
Unit
min.
typ.
max.
1.1
1.35
1.6
V
50
MHz
60
°C
–10
25
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For:Natertech
April 2003
RX3140
Electrical Characteristics
(VCC = 1.4 V, VSS = 0 V, TA = 25 °C, BS = high unless otherwise noted)
Parameter
Symbol
Condition
Value
min.
ICC,total
Quiescent current consumption
Unit
typ.
max.
1.1
1.6
mA
5
µA
16
dB
ICC,standby
VBS = 0 V
Mixer conversion gain
GC
measured after 455 KHz
ceramic filter
Mixer input intermodulation intercept point
IIP3
–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
Standby current consumption
FSK output duty ratio
Low battery alarm threshold voltage
Regulator output voltage
Charging/discharging current
9
12.5
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
OUT
OUT
Page 5
For:Natertech
April 2003
RX3140
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 V CE ≥ 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.
Page 6
For:Natertech
April 2003
RX3140
Typical Performance Characteristics
2
0
1.8
1.6
-5
1.4
VOD (dB)
ICC (mA)
1.2
1
0.8
VCC=1.4 V
T=300 K
CHARGE=H
0.6
0.4
-10
VCC=1.4 V
T=300 K
IFIN=-53 dBm
fmod=600 Hz
∆f=4 KHz
0 dB=158 mVpk-pk
-15
0.2
0
0
1
2
-20
440
3
VCC (V)
1.4
0.4
1.2
0.35
450
455
460
IFIN (KHz)
465
470
0.3
LPFIN (V)
1
0.8
ALM (V)
445
0.6
0.4
0.25
0.2
VCC=1.4 V
T=300 K
IF=-53 dBm
fmod=600 Hz
∆f=4 KHz
0.15
0.1
0.2
0.05
0
440
0
0
0.5
1
1.5
2
2.5
3
445
450
455
460
465
470
IFIN (KHz)
VCC (V)
80
60
I(CHARGE) (
µ A)
40
20
0
-20
VCC=1.4 V
T=300 K
-40
-60
-80
0
0.1
0.2
0.3
0.4
0.5
FSKREF (V)
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For:Natertech
April 2003
RX3140
Test Circuit
0.01 µF
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
330 pF
68 KΩ
68 KΩ
560 pF
68 KΩ
VOD
100 KΩ
100 KΩ
2SA1015GR
430 Ω
2.2 µF
1 nF
VFSKOUT
VALM
VCC
51 Ω
VREGOUT
CHARGE/
DISCHARGE
CIRCUIT
MIXER
QUAD
DETECTOR
OSCILLATOR
IFAMP
39 pF
10 µF
22 KΩ
0.1 µF
56 pF
5
6
DEC
7
FSK
REF
8
IF
OUT
22 pF
9
QUAD
GC
MURATA
CFVM455E
Page 8
For:Natertech
AF
OUT
10
3.3 KΩ
4
IFIN
10 µF
3
VCC
10 µF
2
MIX
OUT
0.1 µF
1
OSC
OUT
VCC
VCC
OSC
IN
VCC
April 2003
RX3140
Application Circuit
LNA
1st mixer
OSCIN
1st IF
amplifier
REGOUT
VCC
REGCON
DEC
FSKREF
IFOUT
QUAD
AFOUT
HiMARK
RX3140
VSS
MIXOUT
IFIN
Frequency
multiplier (×2,3)
MIXIN
OSCOUT
ALM
FSKOUT
CHARGE
BS
LPFOUT
LPFIN
1st LO
XIN
TEST
XOUT
DB
DO
VSS
FIN
VDD1
HiMARK
FS8107E
VDD2
RAM
ROM
CPU
Decoder
NC
OPR
LE
DATA
CLK
LD
NC
LCD driver
Driver
LCD
DC/DC
converter
Page 9
For:Natertech
April 2003