ADM232LJR - 5V 120kbps RS-232 Transceiver | Analog Devices
MPN: ADM232LJR ✓ ActiveADM232LJR Overview
An RS-232 transceiver is an interface IC that converts logic-level signals into differential bipolar voltages for transmission and converts received bipolar voltages back into CMOS-compatible logic levels. In the product hierarchy, it belongs to the communications interface IC class, where it bridges a host controller or UART with a cable-based RS-232 port. Unlike RS-422 and RS-485 interfaces, RS-232 uses single-ended signaling referenced to ground and is primarily intended for point-to-point communication.
The ADM232LJR operates from a single 5 V supply and supports data rates up to 120 kbps. Its integrated DC-DC converter generates the positive and negative voltage levels required by the EIA-232-E drivers without requiring an external dual supply. Other documented features include low-power shutdown, 1 µF external charge-pump capacitors, approximately ±9 V driver output swing from a 5 V supply, and receiver input protection rated to 30 V.
The device contains two transmit channels and two receive channels, allowing two serial ports or one full-duplex port with flow-control signals to share one package. Its CMOS-compatible digital inputs connect directly to the transmit and shutdown-control circuitry of microcontrollers, DSPs, and embedded processors. The balanced set of receive and transmit functions supports protocol-handshake signals as well as primary data channels without requiring separate RS-232 line-driver ICs.
Typical uses include industrial serial consoles, point-of-sale equipment, instrumentation, embedded control systems, and legacy peripheral connectivity. The 120 kbps rate comfortably supports many UART protocols and short-distance point-to-point links. Systems that previously used ±12 V RS-232 can simplify their power architecture by using one 5 V rail, provided the selected connector, cable, and protection network are suitable for the intended installation.
Designers should use the manufacturer's recommended charge-pump capacitor values and observe polarity and voltage limits on all interface pins. The 30 V receiver-input rating does not permit unrestricted hot-plug or surge exposure, so external protection may still be required for exposed industrial cabling. The shutdown function should also be checked against the system requirement because the supplied family data states that the receivers remain active while the drivers are shut down.
This page combines verified manufacturer and distributor information, package-aware replacement guidance, application engineering notes, and a specification comparison that are not consolidated on a typical distributor product listing. The alternatives are presented as candidates that still require schematic, pinout, and system-level verification before substitution.
Drop-in alternatives for ADM232LJR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ADM232LJR (same form factor and footprint) — differing in Package, Supply Voltage.
ADM232LAR
✅ Drop-InContact for price
View Datasheet →ADM232AARWZ
✅ Drop-In📋 Reference alternative (not in catalog)
ADM232AARNZ
✅ Drop-In📋 Reference alternative (not in catalog)
MAX232ECDWR
✅ Drop-In📋 Reference alternative (not in catalog)
ADM232LJR Specifications
| Product Type | RS-232 line-driver and receiver transceiver |
| Supply Voltage | 5 V |
| Number of Drivers | 2 |
| Number of Receivers | 2 |
| Maximum Data Rate | 120 kbps |
| Driver Output Swing | ±9 V |
| Charge-Pump Capacitor Value | 1 µF |
| Receiver Input Voltage Rating | 30 V |
| Power Supply Configuration | Single 5 V supply |
| DC-DC Converter | Onboard |
| Shutdown Feature | Low-power shutdown; receivers active in shutdown |
| Interface Standard | EIA-232-E and V.28 |
| Logic Technology | CMOS |
| Package | 16-pin SOIC |
| Mounting Type | Surface mount |
ADM232LJR 16-pin soic Pin Configuration Guide
Pin configuration for ADM232LJR (16-pin soic package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for ADM232LJR.
Refer to the datasheet for full pin configuration.
Typical Applications
ADM232LJR is suitable for 6 applications: Industrial UART Control Panels, Point-of-Sale Terminals, Test and Measurement Instrumentation, Embedded Data Acquisition, Legacy Peripheral Connectivity, Low-Power Serial Gateways.
Industrial UART Control Panels
The ADM232LJR fits industrial control panels that expose a legacy RS-232 service port while the main controller operates from 5 V logic. Its single 5 V supply and onboard DC-DC converters avoid separate ±12 V rails, and the 120 kbps rate covers standard UART traffic. Two transmitters and two receivers can carry command data and hardware-control signals in one 16-pin SOIC. Designers should still add suitable protection for cables leaving an enclosure because the 30 V receiver-input rating does not replace industrial surge protection.
Recommended
Point-of-Sale Terminals
The ADM232LJR can connect a 5 V point-of-sale controller to a serial printer, scanner, or display using RS-232. Its 120 kbps maximum data rate is appropriate for short point-to-point UART links, while the integrated DC-DC converter simplifies a single-rail terminal design. The two-driver, two-receiver arrangement supports data and control paths without separate line-driver packages. Layout should keep charge-pump capacitors close to the device and maintain a quiet ground return to the connector.
Recommended
Test and Measurement Instrumentation
The ADM232LJR is useful for laboratory and field instrumentation that must communicate with a PC or controller through RS-232. A 120 kbps rate is sufficient for command traffic and moderate diagnostic data, and the single 5 V supply reduces adapter complexity. The onboard DC-DC circuitry provides the required bipolar drive levels without a separate ±12 V source. Because RS-232 is unbalanced and ground-referenced, use a short cable, a common ground path where permitted, and protection appropriate to the installation environment.
Recommended
Embedded Data Acquisition
The ADM232LJR can bridge a 5 V embedded data-acquisition controller to an RS-232 host or peripheral. Its two transmit and two receive channels permit a bidirectional link plus handshake signals, and the 120 kbps limit is suitable for many sensor and configuration commands. Operating from one 5 V rail simplifies isolated or battery-derived systems where ±12 V is impractical. Firmware should avoid assuming a higher rate merely because the host port supports faster UART baud rates.
Recommended
Legacy Peripheral Connectivity
The ADM232LJR provides a practical way to retain RS-232 compatibility when the host controller uses only 5 V power. It replaces the need for a dual-supply line interface by generating the required positive and negative levels internally, while its 120 kbps rate covers conventional serial peripherals and service consoles. The 16-pin SOIC package is suitable for moderate-density industrial boards. Before redesigning around the part, verify the legacy device's driver and receiver levels, handshake timing, and cable pinout.
Recommended
Low-Power Serial Gateways
The ADM232LJR can be used in a compact serial gateway that translates between a 5 V UART processor and an RS-232 equipment network. Its low-power shutdown mode can reduce consumption when the interface is not transmitting, although the supplied family data notes that receivers remain active in shutdown. The 120 kbps data rate and two channels per direction suit low-bandwidth supervisory or configuration links. Power-budget calculations must include the receiver state during shutdown rather than assuming the entire transceiver is off.
Recommended
Recommended Products Summary
Engineering reference data for ADM232LJR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADM232LAR | ADM232AARWZ | ADM232AARNZ | MAX232ECDWR |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Maxim Integrated |
| Package | 16-pin SOIC | 16-pin SOIC | 16-pin SOIC | 16-pin SOIC | 16-pin SOIC |
| Product Type | RS-232 transceiver | Dual transmitter/receiver RS-232 | RS-232 transceiver | RS-232 transceiver | RS-232 transceiver |
Key Differentiators
- Single-rail operation with onboard voltage conversion (vs MAX232ECDWR)
- Defined family data rate (vs MAX232ECDWR)
- Receiver behavior during shutdown (vs MAX232ECDWR)
- Documented external charge-pump capacitance (vs ADM232LAR)
Design Notes
Place the 1 µF charge-pump capacitors and associated loop area as close as practical to the pins specified by the Analog Devices family datasheet. Keep the high-current switched-capacitor loop compact and avoid routing it beneath sensitive analog or communication nodes. Because RS-232 is single-ended, provide a continuous ground reference between the board and connected equipment where the interface standard and application permit it.
Budget the 5 V supply for both logic load and the ADM232LJR's internally generated charge-pump current. The verified data specifies a single 5 V input and onboard DC-DC converters, but it does not provide a numeric supply-current limit, so use the family datasheet and worst-case driver loading before selecting the regulator. Place local input decoupling near the device and validate startup across the full cable-load condition.
Do not treat the 30 V receiver-input rating as permission for unlimited connector exposure or hot-plug operation. For external industrial cables, add appropriately rated protection and verify that it does not distort receiver thresholds or driver rise times. Also confirm whether the system requires receivers to remain active during shutdown, because the supplied family data states that the ADM232LJR receivers are active in that state.
Separate the protected connector side from the digital logic side of the board, and maintain a direct return path for receiver signals. Avoid sharing narrow ground traces between the RS-232 interface and high-current switching nodes. If the board also supports high-speed digital signals, route the cable-side nets away from clocks, oscillators, and switching regulators to reduce common-mode coupling into the single-ended receiver.
Compliance Information
The supplied excerpts do not provide explicit compliance statements for the ADM232LJR. A comparison page mentions RoHS and REACH, but the underlying compliance values are not shown, so no compliance conclusion has been inferred.