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A7302C---315MHz / 433MHz ASK Transmitter with 1~10Kbps data rate                 

315MHz / 433MHz FSK Transmitter with 1~20Kbps data rate

1. General Description A7302C is a very easy-to-use CMOS RF transmitter for sub 1GHz license free ISM band (315/433MHz). It is a FSK/ASK single chip RF transmitter with 4-steps programmable power amplifier (max 10dBm @ 433MHz). This device integrates a fully VCO and PLL synthesizer. A7302C's carrier frequency FRF is determined by the frequency of the reference crystal FXTAL. The integer-N PLL synthesizer ensures that each RF value, ranging from 310 ~ 330 MHz and 425 ~ 445MHz with PLL steps of 847,5KHz ( RF step = 423,75KHz when Xtal = 13,56MHz. because FRF = FVCO / 2 ), can be achieved. This is done by using a crystal as a reference frequency according to: FRF = FXTAL x N / 2R, where N is the PLL feedback divider ratio and R is crystal divider to support 13,56MHz crystal. A7302C supports FSK data rate from 1K to 20Kbps and ASK data rate from 1K to 10Kbps. In FSK modulation, this device’s Fdev (frequency deviation) is controlled by crystal detuning of series an external capacitor (typical 75pF for ± 12,5KHz depending on PCB layout and Xtal type). In ASK modulation, this capacitor is not necessary. For easy-to-use, A7302C has only two control registers, register 0 and 1. MCU can configure two registers via 3-wire SPI bus. In addition to SPI control mode, A7302C has a special mode called HW control mode. In HW control mode, user just needs to apply pin setting. Then, radio control is done (register 0 and register 1 are in default values). No matter HW or SPI control mode, A7302C is very easy to use by a low cost MCU or encoder. Those features are all integrated in a small DFN 10 pins package. For packet handling, there is no FIFO inside A7302C. Hence, MCU or Encoder just delivers the defined packet (preamble + sync word + payload) to TX_DATA pin for data transmitting.

2. Typical Applications

n Remote Control. ■ Wireless Toys. n Alarm and Security System. ■ RKE (Remote Keyless Entry). n Smart Energy Management ■ Garage Door Opener. n AMR (Auto Meter Reading) ■ Home Automation. 3. Features

n Operating range: VDD=2,2~3,6V. T=-40~+85℃. n Small DFN10 package. n Easy to use n HW or 3-wire SPI control mode selection. n HW control mode (no need MCU for radio control, default max TX power). n Auto calibration. n Auto start-up sequence, XtalàAuto CalibrationàPLLà TX. n TX current 14mA (FSK, 10dBm) / 8,8mA (ASK, 10dBm, 50% duty cycle). n Shut down mode current 0,1 uA. n Two stages class-C PA, 4-steps programmable TX Power : 0 / 2 / 7 / 10 dBm. n Fully integrated VCO, on chip loop filter and PLL synthesizer. n RF range from 310 ~ 330MHz and 425 ~ 445MHz with RF steps of 423,75 KHz by 13,56MHz Xtal. n Direct ASK modulation by switching PA. n Direct FSK modulation (frequency deviation) by crystal detuning via external capacitor. n Support low cost crystal (13,56MHz with ± 50ppm tolerance). n Very few external components: No need external IF/SAW filters.