ADM236LAR-REEL

Overview

The ADM236LAR-REEL is a CMOS RS-232 transceiver from Analog Devices, operating on a single 5 V supply. It integrates four drivers and three receivers with internal charge pumps generating ±10 V rails. The device supports data rates up to 120 kbps and features low power shutdown mode consuming less than 5 µW. It includes an active-high shutdown (SD) pin and an active-low enable (EN) pin for receiver control. The component meets EIA-232-E specifications, utilizes small 1 µF capacitors, and operates within a temperature range of -40°C to +85°C.

Feature Summary

• Integrates dual charge pump voltage converters to generate required RS-232 levels from a single 5 V supply without external transformers.
• Features a low power shutdown mode that significantly reduces current consumption, making it suitable for battery-powered applications.
• Includes dedicated enable and shutdown control inputs to manage transmitter and receiver states independently.

Applications

• Battery-powered computers and portable instruments
• Modems and printers requiring RS-232 interfaces
• Peripherals where space-saving and low power are critical

Procurement Notes

Verify the specific suffix 'AR' indicates the industrial temperature grade (-40°C to +85°C) and 'L' denotes the low-power variant. Confirm the '-REEL' designation matches the required tape and reel packaging quantity for your assembly line. Cross-reference the manufacturer's latest ordering guide to ensure the part number reflects current production status and any potential revisions.

Selection Notes

Select this component when a single 5 V supply is available but standard RS-232 voltage levels are required. It is appropriate for designs needing multiple transmit and receive channels with independent control capabilities. Consider the package size and thermal requirements relative to the PCB layout constraints. Ensure the application does not require higher baud rates or different logic voltage levels than supported by the CMOS inputs.

Part Context

This part belongs to the ADM2xxL family of enhanced RS-232 transceivers designed as upgrades to older AD2xx series parts. The L-series offers lower power consumption and faster slew rates compared to predecessors. The ADM236L specifically provides a balanced mix of four drivers and three receivers, distinguishing it from simpler two-channel variants in the same family.

Replacement Considerations

The ADM236L serves as a direct upgrade for the AD236. Verify compatibility with other ADM2xxL family members if channel counts differ. Check datasheets for alternative transceivers from other manufacturers only if they explicitly state pin-to-pin and electrical equivalence to the ADM236L.

FAQ

How does the shutdown mode affect the receiver outputs?

When the SD pin is driven high, the charge pump is disabled, and all receiver outputs are placed in a high impedance state.

What is the purpose of the EN pin on the ADM236L?

The EN pin is an active-low input used to disable receiver outputs, placing them in a high impedance state while leaving transmitters operational.

Can unused TTL/CMOS inputs be left unconnected?

Yes, unused inputs have internal pull-up resistors that force the outputs into a low state if left unconnected.