PT4455
PLL-based OOK/ASK Transmitter IC
DESCRIPTION
PT4455 is a high performance OOK/ASK
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 OOK/ASK transmitter
High output power, 3V /+11dBm /17mA
Low supply voltage, 2.2V to 3.6V operation range
Low external component cost.
PLL-based transmitter with frequency range from
300MHz to 450MHz
On-chip one-shot circuit
60dB RF on-off ratio for OOK/ASK modulation
Available in 6-pin, SOT-23 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
PT4455
APPLICATION CIRCUIT
C1
X1
C2
R5
VDD
C3
R3
C7
1
XOUT
VSS
PAOUT
XIN
6
L1
L2
C6
C5
C4
2
3
VDD
PT4455
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
9.844M
10K
100K
0
0
560K
22p
22p
1μ
220p
8.2p
18p
2.2μ
180n
33n
433.92MHz
13.56M
10K
100K
0
0
560K
18p
18p
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:
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.
4. To populate the R5 over XIN will help to maintain good oscillation in high X1 ESR.
V1.1
2
January 2013
PT4455
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
V1.1
8
January 2013