Preliminary
PT4456
PLL-based FSK Transmitter IC
DESCRIPTION
PT4456 is a high performance FSK transmitter for
the Remote Keyless Entry (RKE) systems. It
consists of a power amplifier, one-shot circuit and
phase-locked loop with internal voltage controlled
oscillator and loop filter. The one-shot circuit
control the phase-locked loop and power amplifier
to have fast start-up time in operation.
FEATURES
Highly integrated FSK transmitter
High output power, 3 V /+11 dBm / 17 mA
Low supply voltage, 2.2 V to 3.6 V operation range
Low external component cost.
PLL-based transmitter with frequency range from
300MHz to 450MHz
On-chip one-shot circuit
SOT23-6 package
APPLICATIONS
Keyless entry systems
Remote control systems
Garage door openers
Alarm systems
Security systems
Wireless sensors
BLOCK DIAGRAM
XIN
VDD
DIN
6
5
Vreg
4
Oneshot
P
L
L
PA
1
XOUT
2
VSS
3
PAOUT
Tel: 886-66296288
‧
Fax: 886-29174598
‧
http://www.princeton.com.tw
‧
2F, No. 233-1, Baociao Rd., Sindian Dist., New Taipei City 23145, Taiwan
PT4456
APPLICATION CIRCUIT
C1
X1
C2
R5
VDD
C3
R3
C7
1
XOUT
VSS
PAOUT
XIN
6
L1
L2
C6
C5
C4
2
3
PT4456
VDD
VDD
DIN
5
R4
4
R1
DIN
R2
BILL OF MATERIALS
Part
X1
R1
R2
R3
R4
R5
C1
C2
C3
C4
C5
C6
C7
L1
L2
Value
315MHz
9.84175M
10K
100K
0
10
560K
10p
10p
1μ
220p
8.2p
18p
2.2μ
180n
33n
433.92MHz
13.558M
10K
100K
0
10
560K
10p
10p
1μ
220p
4.7p
10p
2.2μ
180n
27n
Unit
Hz
Ω
Ω
Ω
Ω
Ω
F
F
F
F
F
F
F
H
H
Notes
3,4,5
3
1,5
1,5
2
2
2
Notes:
1. C1/C2 can be used to trim the transmitted signal frequency for matching the specified value.
2. L2/C5/C6 value will depend on PCB layout.
3. The recommend maximum ESR value of X1 is 40Ω. To populate R5 over XIN will help to maintain good oscillation in high X1 ESR.
4. For FSK application to have adequate frequency deviation, and accurate carrier frequency, the crystal resonator frequency will be lower than the
specified value. The recommended crystal resonator frequency is 9.84175MHz and 13.558MHz.
5. For higher X1 ESR, load capacitor C2 can be reduced or removed to maintain good oscillation. In narrowband application with accurate frequency
requirement, trimming the C1 capacitor or change the crystal resonator frequency is suggested.
6. The PCB layout is scaled to get good reading. The actual PCB size is about 1.1x1.3 cm
PRE1.1
2
September 2014
PT4456
ORDER INFORMATION
Valid Part Number
PT4456
Package Type
6 Pins, SOT23
Top Code
PT4456
PIN CONFIGURATION
XOUT
VSS
PAOUT
1
2
3
6
XIN
VDD
DIN
PT4456
5
4
PIN DESCRIPTION
Pin Name
XOUT
VSS
PAOUT
DIN
VDD
XIN
I/O
O
G
O
I
P
I
Description
Oscillator output
Ground connection
Power amplifier output
Data input
Power supply
Oscillator input
Pin No.
1
2
3
4
5
6
PRE1.1
3
September 2014
PT4456
IMPORTANT NOTICE
Princeton Technology Corporation (PTC) reserves the right to make corrections, modifications, enhancements,
improvements, and other changes to its products and to discontinue any product without notice at any time.
PTC cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a PTC product. No
circuit patent licenses are implied.
Princeton Technology Corp.
2F, 233-1, Baociao Road,
Sindian Dist., New Taipei City 23145, Taiwan
Tel: 886-2-66296288
Fax: 886-2-29174598
http://www.princeton.com.tw
PRE1.1
8
September 2014
实时操作系统RTOS
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