ADM234LJR

Overview

The ADM234LJR is a single-supply CMOS RS-232 transceiver from Analog Devices, designed for EIA-232-E and V.28 interfaces without requiring external ±12 V supplies. It integrates two internal charge pump voltage converters to generate the necessary ±10 V levels from a single +5 V input (VCC = 5 V ± 10%). The device provides four drivers and zero receivers, supporting data rates up to 120 kbps with an output voltage swing of ±9 V under typical loading. It utilizes small 1 µF external capacitors for the charge pumps and operates within a commercial temperature range of 0°C to 70°C. The component is housed in a 16-pin SOIC package.

Feature Summary

• Integrates dual charge pump voltage converters to generate required RS-232 supply voltages from a single 5 V source
• Provides four TTL/CMOS-to-RS-232 drivers for high-density serial communication applications
• Features Schmitt trigger inputs on receiver sections (where applicable) to ensure noise immunity and error-free reception
• Includes internal pull-up resistors on driver inputs to simplify unused pin handling

Applications

• Computers and peripheral interface connections
• Modems and printers requiring RS-232 signaling
• Instruments and industrial control systems

Procurement Notes

Verify the ordering suffix 'JR' corresponds to the specific 16-lead Small Outline Package (SOIC) variant and the commercial temperature grade (0°C to 70°C). Confirm that the procurement matches the Rev. C datasheet specifications, particularly regarding the absence of receiver channels and the requirement for four external 1 µF capacitors for the integrated charge pumps.

Selection Notes

Select the ADM234LJR when a design requires multiple transmit channels but no receive channels on a single IC. This part is suitable for applications needing four independent RS-232 drivers powered by a standard 5 V logic supply. Ensure the PCB layout accommodates the four required 1 µF capacitors for the internal voltage doublers and inverters, as these are essential for proper operation.

Part Context

The ADM234L is part of the ADM2xxL family of enhanced CMOS RS-232 line drivers and receivers. This family serves as an upgrade to the older AD2xx series, offering lower power consumption, faster slew rates, and compatibility with smaller 1 µF capacitors. The ADM234L specifically fills the niche for multi-driver applications within this low-power, single-supply ecosystem.

Replacement Considerations

The ADM232L is a functional alternative within the same family but includes two receivers in addition to its two drivers. If the application requires only transmission, the ADM234L is more appropriate; if bidirectional communication is needed, the ADM232L should be considered instead.