Microchip's broad product portfolio allows the design of complete LF RFID systems, be it passive or active. The passive products are also compliant to the ISO animal ID standards 11784 and 11785. In addition to the 100-150kHz LF downlink path, active systems also have a return link in the UHF band at 315 or 433MHz. The proper band to use depends on the individual country regulations. For both systems, LF readers and UHF receiver ASSPs are available. The latest development in passive LF RFID is a single-chip reader, a 16kB Flash AVR MCU with LF ASK reader peripheral.