ADM222AR

Overview

The ADM222AR is a high-speed RS-232 line driver and receiver manufactured by Analog Devices Inc. It operates from a single 5 V power supply and supports transmission rates up to 200 kB/s. The device integrates two drivers and two receivers, utilizing an on-board DC-DC converter with small 0.1 µF external capacitors to generate bipolar voltage levels. It features a shutdown function that reduces supply current to 0.1 µA. The component meets EIA-232-E and V.28 specifications and is housed in an 18-lead Standard Small Outline Package (SOIC).

Feature Summary

• Integrates on-chip charge pump voltage converters requiring only small external capacitors.
• Includes a dedicated shutdown pin to minimize power consumption when the device is inactive.
• Features Schmitt trigger inputs on receivers to ensure noise immunity and error-free reception.
• Provides internal pull-up resistors on transmitter inputs to simplify unused pin handling.

Applications

• Computer serial communication ports
• Peripheral interface connections
• Modem data transmission links
• Printer interface circuits
• Industrial instrument control systems

Procurement Notes

Verify the specific package variant against the ordering guide, as the base model number may correspond to different physical packages such as DIP or SOIC. Confirm RoHS compliance status if required for assembly standards. Ensure the selected part matches the required temperature range for the intended operating environment before finalizing procurement orders.

Selection Notes

Select this component when a dual-channel RS-232 transceiver with low quiescent current is required. The integrated shutdown feature makes it suitable for battery-powered applications where power conservation is critical. Verify compatibility with existing TTL/CMOS logic levels and ensure the PCB layout accommodates the necessary external capacitor placement for the charge pump circuit.

Part Context

The ADM222AR belongs to the ADM222/ADM232A/ADM242 family of CMOS RS-232 drivers and receivers. This family shares common architectural features but differs in control functions; specifically, the ADM222 includes a shutdown pin while the ADM242 adds an enable function. The ADM232A variant lacks these control pins but offers similar electrical performance for standard interface applications.

Replacement Considerations

The datasheet indicates pin compatibility with MAX222, MAX232A, and MAX242 devices. When substituting, verify that the alternative component supports the same 200 kB/s data rate and 5 V supply requirements. Ensure the replacement maintains the required shutdown functionality if low-power standby modes are utilized in the design.