MAX3218CAP+T

Overview

The MAX3218CAP+T is a dual-driver, dual-receiver RS-232 transceiver designed for battery-powered EIA/TIA-232E and V.28/V.24 interfaces. It operates from a single supply voltage ranging from +1.8V to +4.25V, enabling direct connection to two alkaline, NiCd, or NiMH cells without external regulators. The device guarantees a data rate of 120kbps while maintaining true RS-232 and EIA/TIA-562 voltage levels. It features an AutoShutdown function that reduces supply current to 1µA when no valid signal is detected on the receiver inputs. The component is housed in a 20-pin SSOP package and supports an operating temperature range of 0°C to +70°C.

Feature Summary

• AutoShutdown technology minimizes power consumption by disabling the onboard power supply and drivers when invalid signal levels are detected on receiver inputs.
• Integrated switch-mode DC-DC converter generates internal ±6.5V rails from a low-voltage single supply using minimal external components.
• Three-state receiver outputs allow multiple receivers with different interface standards to be connected on the same bus.
• Logic-controlled FORCEON and FORCEOFF pins enable manual override of the automatic shutdown state.

Applications

• Battery-powered subnotebook computers
• Personal Digital Assistants (PDAs)
• Hand-held equipment and peripherals
• Cellular phones

Procurement Notes

Verify the specific suffix CAP+T corresponds to the 20-pin SSOP package and commercial temperature range (0°C to +70°C). Confirm RoHS compliance status as indicated by the '+' designation. Ensure the ordering quantity matches distributor minimums and check lead times for availability before finalizing procurement plans.

Selection Notes

Select this component for applications requiring low-power RS-232 communication directly from two-cell battery packs. It is suitable where system software cannot be modified to manage power states, as the AutoShutdown feature operates independently. Verify that the required data rate does not exceed 120kbps and that the application environment remains within the commercial temperature limits.

Part Context

The MAX3218 belongs to the Maxim Integrated RS-232 transceiver family, specifically engineered for portable electronics. It shares functional similarities with the MAX218 but includes proprietary AutoShutdown circuitry for enhanced power efficiency. The device replaces older bipolar-based transceivers, offering lower supply currents and compatibility with modern low-voltage CMOS logic systems.

Replacement Considerations

The MAX218 is a pin-compatible alternative within the same series but lacks the AutoShutdown feature. For applications requiring extended temperature ranges, the MAX3218EAP+ variant offers operation from -40°C to +85°C in the same SSOP package.