ADM239LJR

Overview

The ADM239LJR is a CMOS RS-232 transceiver from the ADM2xxL family, designed for EIA-232-E and V.28 interfaces. It features three drivers and five receivers in a 24-pin package. The device requires dual supplies: VCC at 5 V ± 10% and an external V+ ranging from 7.5 V to 13.2 V. An internal charge pump generates a negative supply (V–) using two external 1 µF capacitors. Key electrical parameters include a typical output voltage swing of ±9 V, a data rate capability of 120 kbps, and a low power shutdown mode with current consumption ≤1 µA. The receiver inputs tolerate levels up to ±30 V.

Feature Summary

• Integrates a negative charge pump voltage converter to generate the required negative supply rail from a single positive input.
• Includes an active-low enable function that places receiver outputs in a high impedance state for bus sharing.
• Features Schmitt trigger inputs on receivers to ensure error-free reception in noisy environments or with slow transition times.
• Complies with EIA-232-E specifications while operating from standard digital logic supply voltages.

Applications

• Battery-powered equipment requiring low power consumption
• Modems and printers
• Computers and peripheral instruments

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm the package type and temperature range. Ensure the component matches the required RoHS compliance status for your assembly process. Cross-reference the part number with the latest datasheet revision to confirm pinout and electrical characteristics remain unchanged.

Selection Notes

Select this component when an RS-232 interface requires multiple receivers but only one driver. Unlike other members of the ADM2xxL family, this part does not generate a positive charge pump voltage internally; it requires an external positive supply between 7.5 V and 13.2 V. Verify that the application can accommodate the necessary external capacitors for the internal voltage inverter.

Part Context

The ADM239L belongs to the ADM2xxL enhanced series, which offers lower power consumption and faster slew rates compared to the legacy AD2xx family. This specific variant is distinct because it lacks the internal positive voltage doubler found in parts like the ADM236L, necessitating an external positive supply source while retaining the internal negative charge pump.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.