Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Low Power 315/433 MHz OOK/ASK Superheterodyne
Receiver with SAW-based Oscillator
PT4316
DESCRIPTION
The PT4316 is a very low power consumption single chip OOK/ASK superheterodyne receiver for the
315MHz and 434MHz frequency bands and which offers a high level of integration and requires few
external components. The PT4316 consists of a low-noise amplifier (LNA), mixer, SAW-based local
oscillator, on-chip Sallen-Key low-pass filter, intermediate frequency (IF) limiting amplifier stage with
received-signal-strength indicator (RSSI), and analog baseband data recovery circuitry (data filter,
peak detector, and data slicer). The PT4316 also implements a discrete one-step automatic gain
control (AGC) that reduces the LNA gain by 20dB when the RF input signal is greater than -60dBm.
The PT4316 is available in a 16-pin SOP or SSOP package. Both versions are specified over the
extended temperature range (-40℃ to +85℃).
FEATURES
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•
•
•
•
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Low current consumption (4.2mA at VDD = 3.0V)
2.4V to 3.6V supply voltage operation range
Optimized for 315MHz or 434MHz ISM Band
Saw-based oscillator with low frequency drift
High dynamic range with on-chip AGC
Power down mode with very low supply current (<1µA)
Low external parts count
Available in 16 pins, SOP or SSOP package
APPLICATIONS
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•
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Keyless entry systems
Remote control systems
Garage door openers
Alarm systems
Security systems
Wireless sensors
PT4316 V1.6
-1-
August, 2007
Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Low Power 315/433 MHz OOK/ASK Superheterodyne
Receiver with SAW-based Oscillator
PT4316
BLOCK DIAGRAM
OSCOUT
16
OSCIN
15
VSS
14
DATA
13
DSN
12
PDOUT
11
OPP
10
VDD
9
Data Slicer
SAW Oscillator
Buffer
Data Filter
Peak Detector
AGC
RSSI
Limiter with RSSI
BIAS
LNA
Mixer IF Low-pass Filter
1
2
3
4
5
6
7
8
CE
CAGC
RFIN
VSSLNA
LNAOUT
LIMIN
DFFB
DSP
PT4316 V1.6
-2-
August, 2007
Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Low Power 315/433 MHz OOK/ASK Superheterodyne
Receiver with SAW-based Oscillator
PT4316
PIN CONFIGURATION
PT4316 V1.6
-3-
August, 2007
Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Low Power 315/433 MHz OOK/ASK Superheterodyne
Receiver with SAW-based Oscillator
PT4316
PIN DESCRIPTION
Pin Name
CE
CAGC
RFIN
VSSLNA
LNAOUT
LIMIN
DFFB
DSP
VDD
OPP
PDOUT
DSN
DATA
VSS
OSCIN
OSCOUT
I/O
I
O
I
G
O
I
I
I
P
I
O
I
O
G
I
O
Description
Chip enable
AGC capacitor
RF input
Ground for LNA
LNAOUT
Limiting amplifier de-coupling input
Data filter feedback point
Positive input of data slicer (data filter output)
Power supply
Non-inverting op-amp input
Peak detector output
Negative input of data slicer
Data output
Ground
Oscillator input
Oscillator output
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
PT4316 V1.6
-4-
August, 2007
Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Low Power 315/433 MHz OOK/ASK Superheterodyne
Receiver with SAW-based Oscillator
PT4316
FUNCTION DESCRIPTION
The PT4316 CMOS superheterodyne receiver provides the functionality of a complete receive chain
from an antenna input to digital data output. Depending upon signal power and component selection,
data rates as high as 50 Kb/s may be achieved.
LOW NOISE AMPLIFIER (LNA)
The LNA is an on-chip cascode amplifier with a power gain of 16dB and a noise figure of 3dB. The gain
is determined by external matching networks situated ahead of the LNA and between the LNA output
and the mixer input.
An example of the input matching network and the input impedance of PT4316 for 315/434MHz bands
are shown in the following figure. The component values given in the table following the application
circuit are nominal values only. For a particular PCB layout, the user may be required to make
component adjustments in order to achieve highest sensitivity.
C3
C2
3
RFIN
C4
Frequency
(MHz)
315
433.92
LNA Input Impedance (Pin 3)
Normalized to 50Ω
4.18—j251.63
3.60—j180.20
The LNA output of PT4316 internally connects to the mixer stage so that its output impedance cannot
be measured directly. The LNA output requires a DC supply through a choke inductor. For obtaining
better LNA gain, a capacitor is recommended to be added in parallel with this inductor to implement a
resonant tank at the desired frequency as shown in the following figure. Note that the LNA might
self-oscillate and degrade the receiver sensitivity, particularly if a large inductor value is chosen. An
alternate matching method is to replace the parallel capacitor with a 330 to 1KΩ resistor, which would
reduce the resonant tank Q (quality factor) and avoid the self-oscillation.
VDD
R1
L2
C5
5
LNAOUT
C8
PT4316 V1.6
-5-
August, 2007
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