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General Description |
bands. A7229 incorporates a baseband demodulator with the programmable data rate up to 250Kbps. For a battery powered system, A7229 supports fast PLL settling time (120 us), Xtal settling time (1100 us) and on-chip Regulator settling time (850 us) to reduce average power consumption. The RF synthesizer contains a VCO and a low noise fractional-N PLL. The VCO frequency operates at the wanted radio frequency to cover all RF band. A7229’s control registers are accessed via 3-wire SPI interface. Another one, via SPI as well, is the unique strobe command. A7229 can be controlled from power saving mode (deep sleep, sleep, idle, standby), PLL mode, and RX mode. In addition to SPI, the digital connection between A7229 and MCU is GIO1 (multi-function GPIO) to indicate A7229’s status so that MCU could use either polling or interrupt for radio control. Additional device features such as on-chip regulator, RSSI for clear channel assessment, low battery detector, carrier detect, preamble detect, AIF (Auto IF function), AFC (Auto Frequency compensation), Auto calibration (VCO, IF Filter), PLL/CLK Generator, on-chip compensated capacitors of Xtal loading. Overall, A7229’s highly integrated features and low current consumption offer a reduced BOM cost for a high performance ISM bands product. For easy-to-use, A7229 has a special mode called HW control mode. In HW control mode, user just needs to apply pin setting for radio control, i.e. BAND =1 for 433.92MHz and BAND = 0 for 315MHz. SDR=0 for data rate 10K application. For packet receiving, there is no RX FIFO inside A7229. MCU just needs to process the coming packet (preamble + sync word + payload) from GIO1 pin. Hence, A7229 is very easy to use with a low cost MCU. Those features are all integrated in a small QFN 20 pins package. |