PT4456

Preliminary PT4456 PLL-based FSK Transmitter IC DESCRIPTION FEATURES      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. 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 4 Vreg Oneshot P L L PA 1 2 3 XOUT VSS 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 X1 C1 C2 R5 VDD C3 R3 C7 XOUT 2 VSS L1 L2 C6 C5 C4 XIN PT4456 6 VDD 5 DIN 4 VDD 1 R4 3 PAOUT 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 Notes Hz Ω Ω Ω Ω Ω F F F F F F F H H 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 Package Type Top Code PT4456 6 Pins, SOT23 PT4456 PIN CONFIGURATION XOUT 1 VSS 2 PAOUT 3 PT4456 6 XIN 5 VDD 4 DIN PIN DESCRIPTION PRE1.1 Pin Name I/O Description XOUT VSS PAOUT DIN VDD XIN O G O I P I Oscillator output Ground connection Power amplifier output Data input Power supply Oscillator input 3 Pin No. 1 2 3 4 5 6 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