ADM241LJR-REEL

Overview

The ADM241LJR-REEL is a CMOS RS-232 transceiver from Analog Devices, operating on a single 5 V supply. It integrates four drivers and five receivers within a 28-pin SOIC package. The device supports data rates up to 120 kbps and features internal charge pumps generating ±10 V supplies using only four 1 µF external capacitors. Key electrical parameters include a power supply voltage range of 4.5 V to 5.5 V, a typical supply current of 13 mA, and an output voltage swing of ±9 V under load. It includes low power shutdown and enable functions for system control.

Feature Summary

• Integrates dual charge pump converters to generate required RS-232 voltages from a single 5 V source
• Features low power shutdown mode reducing dissipation below 5 µW for battery applications
• Includes receiver enable input allowing high impedance state for bus sharing
• Provides Schmitt trigger inputs with hysteresis for noise immunity

Applications

• Battery-powered portable equipment requiring low standby power
• Microprocessor systems utilizing shared data buses
• Industrial instruments and peripherals interfacing via RS-232

Procurement Notes

Verify the specific suffix 'JRZ' corresponds to the industrial temperature grade (-40°C to +85°C) and SOIC-28 package configuration as defined in the manufacturer's ordering guide. Confirm that the 'REEL' designation indicates tape-and-reel packaging suitable for automated assembly processes rather than tube packaging.

Selection Notes

Select this component when designing systems requiring five receiver channels alongside four drivers. The integrated shutdown and enable controls are critical for managing power consumption in portable devices or for isolating receivers on multipoint communication lines. Ensure the application utilizes standard 1 µF ceramic capacitors for the charge pump circuitry to maintain optimal performance.

Part Context

This part belongs to the ADM2xxL family of enhanced CMOS RS-232 transceivers. It serves as an upgrade to the legacy AD2xx series, offering lower power consumption and faster slew rates. The ADM241L specifically distinguishes itself within the family by providing the highest channel count (four drivers, five receivers) while maintaining single-supply operation and advanced power management features.

Replacement Considerations

ADM236L: Offers similar functionality but with fewer receiver channels (three instead of five).

FAQ

How does the shutdown function affect the charge pump?

When the SD pin is driven high, the internal charge pump is disabled, turning off the driver outputs and placing receiver outputs in a high impedance state.

What is the purpose of the EN pin on the ADM241L?

The EN pin allows the receiver outputs to be placed in a high impedance state when driven high, facilitating connection to microprocessor data buses or shared lines.

Does the ADM241L require external components for voltage generation?

Yes, it requires four external 1 µF capacitors to support the internal charge pump voltage doublers and inverters.