MAX3320AEAP+ [Analog Devices]

The MAX3320 combines a microprocessor (µP) supervisory circuit with an RS-232 transceiver. The power-on reset performs a single function: it asserts a reset signal whenever the VCC supply voltage declines below a preset threshold, staying asserted for at least 100ms after VCC rises above the reset threshold. The MAX3320 has an active-low RESET output, which is guaranteed to be in the correct state for VCC down to 1V. The reset comparator is designed to ignore fast transients on VCC. Reset thresholds suitable for operation with a variety of supply voltages are available. The MAX3320 transceivers have a proprietary low-dropout transmitter output stage, enabling true RS-232 performance with a dual charge pump powered from a +3V to +5.5V supply. The device requires only four small 0.1µF external charge-pump capacitors, and is guaranteed to run at data rates of up to 250kbps. It comes in the space-saving 20-pin SSOP package.