Transceiver IC meets very-short-range needs
By Bill Schweber -- EDN, April 29, 2004
Many wireless applications don’t need and, in fact, don’t want range; they do need extremely low power and can tolerate low data rates. The AMIS-52100 from AMI Semiconductor is a single-chip transceiver for operation below 500 MHz; it is well-suited to applications such as 402- to 405-MHz, implantable medical devices (Picture). The IC uses well-known and simple amplitude-shift keying for transmitter-side modulation, the receiver path includes clock- and data-recovery circuitry. Its receiver optimally samples the data bit stream using its derived, synchronized clock to minimize jitter and, thus, bit-error rate. At 1 kbps, the device has a bit-error rate of 10–3 with a –117-dBm signal; maximum data rate is 8 kbps.
Because power is precious in these applications, the IC features a “sniff” mode in which it turns the internal oscillator on to full-operation mode within 15 μsec to quickly check for a sufficiently strong signal. Users can adjust the sniff-mode threshold, the period, and many other operating parameters. The 20-lead SSOP device operates from a 2.4 to 3.6V supply; transmitting-current consumption is 25 mA, and receiver consumption is 7.5 mA. At single-digit-percent duty-cycle operation, average power consumption is far less. The $1.95 IC (50,000) meets relevant FCC and ETSI requirements.
AMI Semiconductor, 1-208-233-4690, www.amis.com.
