ACS104A

The ACS104A is a complete controller, driver and receiver IC, supporting fullduplex asynchronous transmission from DC to 162kbps over a serial link.Improved sensitivity and additional operating modes are offered over the ACS104. Although primarily designed to be used with standard LED emitters and PIN receivers and twin optical fibers, any other simple serial media may be used.The ACS104A is optimised for very low power consumption, consuming only 2 -
3mA at RS-232 data rates including power provided to the LED and 'heartbeat' monitor. In applications where the power is extracted from the RS232 data lines,this leaves a generous amount of power left for any power extraction and RS-232 level shifting circuitry.

The ACS104A employs data compression and time compression techniques,affording high launch power in short bursts, leading to a low average power consumption. The advantage of this approach is that high link budgets can be
achieved with inexpensive optical components. For example, the recommended set-up for RS-232 applications (19.2kbps + handshake signals) assumes that the LED is driven with a peak current of approximately 15.4mA for 6 % of the time.The machine cycle is short enough to facilitate power supply smoothing with a small external capacitor in the region of 100F.