ADM231LAR - 5V RS-232 Transceiver, 120kB/s | Analog Devices
MPN： ADM231LAR ✗ 停產ADM231LAR 概覽
An RS-232 transceiver is an interface IC that converts logic-level signals into the bipolar voltage levels used by RS-232 links and converts returning bipolar signals back to CMOS logic. Within the interface hierarchy, this device belongs to the line-driver and receiver family, then to communication transceivers, and finally to the broader category of interface ICs. Its integrated DC-DC converter allows the driver to generate the positive and negative voltage swings required by RS-232 from one 5 V rail.
Key features include a 120 kB/s maximum data rate, on-board DC-DC converters, a 9 V output swing with the 5 V supply, and support for small 1 uF charge-pump capacitors. A low-power shutdown function reduces consumption when the interface is not required. According to the verified feature summary, the receiver remains active during shutdown, allowing incoming signals to be monitored without powering the transmitter section fully.
The receiver input is rated to 30 V, providing tolerance for ±15 V RS-232 signals and additional margin on unused or disconnected receive inputs. These characteristics make the ADM231LAR applicable to legacy serial ports, industrial control links, service equipment, instrumentation, and embedded systems that communicate with older RS-232 equipment.
The principal design trade-off is that the ADM231LAR is a legacy 120 kB/s interface rather than a modern high-speed or multi-port RS-232 solution. Its single-supply architecture simplifies systems that lack ±12 V rails, but obsolete lifecycle status, charge-pump capacitor requirements, and the lower 120 kB/s ceiling limit new design adoption.
When planning a replacement design, engineers should verify the complete pinout, shutdown behavior, charge-pump capacitor values, and package dimensions rather than selecting a substitute from the RS-232 family name alone. The verified sources did not establish five pin-compatible drop-in replacements in the same 16-lead SOIC footprint, so the alternatives listed here are limited to candidates for which comparative information was found.
This page consolidates the verified manufacturer and distributor information, lifecycle status, pricing reference, interface characteristics, and replacement guidance for engineers evaluating an obsolete ADM231LAR inventory.
直接替換替代品，適用於 ADM231LAR — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
ADM232LARZ
✅ 直接替換📋 參考替代品（不在目錄中）
ADM232AARW
✅ 直接替換📋 參考替代品（不在目錄中）
ADM231LAR 規格
| 供應電壓 | 5 V |
| Interface Standard | EIA-232-E and V.28 |
| Maximum Data Rate | 120 kB/s |
| Technology | CMOS |
| DC-DC Converter | On-board |
| Transmitter Output Swing | 9 V with 5 V supply |
| Charge-Pump Capacitor Value | 1 uF |
| Shutdown Feature | Low-power shutdown |
| Receiver State During Shutdown | Active |
| Receiver Input Voltage | 30 V |
| 封裝 | 16-lead SOIC |
| 安裝類型 | Surface Mount |
| 生命週期狀態 | Obsolete |
| Documented Unit Price | 3.79 USD as of 2026-10-30 |
ADM231LAR 16-lead soic 腳位配置指南
ADM231LAR（16-lead soic 封裝）的腳位配置。 腳位編號、功能與連接圖定義於製造商資料手冊中。請參閱該手冊以取得確切的封裝尺寸與焊接指引。
無詳細腳位定義資料： ADM231LAR.
請參閱 資料表 以查看完整腳位配置。
典型應用
ADM231LAR 適用於 6 應用s: Legacy Serial Port Adapter, Industrial Instrument Control, Service and Diagnostic Equipment, Embedded RS-232 Communication, Broadcast and Audio Control Link, Obsolete Equipment Maintenance.
Legacy Serial Port Adapter
The ADM231LAR fits legacy serial-port adapter boards that convert a 5 V logic-level UART into a bipolar RS-232 connection. Its documented 120 kB/s maximum rate is more than adequate for configuration ports, firmware consoles, and equipment-control commands, while the on-board DC-DC converter removes the need for a ±12 V supply. The 9 V output swing and 30 V receiver input rating provide the basic voltage margins required by RS-232 links. Because the part is obsolete, the strongest use case is repairing or cloning an existing board whose 16-lead SOIC footprint and charge-pump layout are already proven.
推薦
Industrial Instrument Control
The ADM231LAR is appropriate for control links between industrial test equipment and a legacy controller operating from a single 5 V rail. The verified EIA-232-E and V.28 support targets the voltage and timing conventions used by older instrumentation, while the 120 kB/s rate comfortably covers command-and-response traffic. Its integrated DC-DC converter simplifies cabling to remote equipment that lacks a bipolar supply. The 30 V receiver input rating adds tolerance at the receive pins, although surge, isolation, and extended-temperature requirements must be reviewed separately because those ratings are not provided in the verified excerpts.
推薦
Service and Diagnostic Equipment
The ADM231LAR can serve as the RS-232 interface in service consoles, diagnostic fixtures, and programmer adapters built around legacy equipment. A 120 kB/s link is suitable for firmware logs, configuration downloads, and status polling, and one 5 V rail simplifies portable test equipment. The receiver remains active during shutdown according to the verified feature summary, which is useful when the interface must monitor a link while conserving power in other sections. Designers should confirm the exact pinout and timing from the manufacturer datasheet before cloning a board because the part is obsolete and the supplied excerpts do not document every electrical limit.
推薦
Embedded RS-232 Communication
The ADM231LAR provides a straightforward interface between a 5 V embedded controller and an RS-232 peripheral. Its CMOS logic side avoids level-shifting components, while the internal charge pump generates the bipolar transmit levels from the single supply. The documented 120 kB/s ceiling is suitable for status and command exchanges rather than file transfer or high-speed sensor streaming. This use case works best for maintenance of existing embedded systems; a new product should consider a currently supported transceiver after checking whether the ADM231LAR's charge-pump topology, shutdown connections, and 16-lead footprint can be reproduced safely.
推薦
Broadcast and Audio Control Link
The ADM231LAR can be used for low-speed control and status signaling between professional equipment and a central controller, provided the equipment follows RS-232 rather than audio-level protocols. The 120 kB/s rate and 9 V output swing suit command traffic, and the single 5 V supply is convenient in rack equipment that already distributes low-voltage power. The receiver's 30 V input rating offers useful margin for standard bipolar signaling. It is not an audio signal-path device, and any ground-offset or long-cable installation still needs engineering review of grounding and protection beyond the values documented in the verified data.
推薦
Obsolete Equipment Maintenance
The ADM231LAR is most relevant to maintenance programs that must restore equipment containing the original 16-lead SOIC device. The verified listing reports 15,600 units in stock and a 3.79 USD unit price as of 2026-10-30, making traceable surplus a practical option for repairs, but it does not imply new-production availability. Engineers should compare the incoming component against the manufacturer datasheet, verify soldering and inspection requirements, and confirm counterfeit-screening processes. For volume redesigns, a currently supported transceiver or a documented board revision is generally safer than building a new line around obsolete inventory.
推薦
推薦產品摘要
工程參考資料，適用於 ADM231LAR — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | ADM232LARZ | ADM232AARW |
|---|---|---|---|
| Package | 16-lead SOIC | 16-lead SOIC | 16-lead SOIC |
| Brand | Analog Devices | Analog Devices | Analog Devices |
| Interface Type | RS-232 driver and receiver | RS-232 driver and receiver | RS-232 driver and receiver |
| Supply Voltage | 5 V | 5 V | 5 V |
| On-Board DC-DC Converter | Yes | Yes | Yes |
主要差異化特點
- Single-rail operation with integrated bipolar voltage generation (對比ADM232LARZ)
- Receive monitoring during reduced-power shutdown (對比ADM232AARW)
- Documented single-unit reference price and reported inventory (對比ADM232LARZ)
- Input tolerance for standard bipolar RS-232 signals (對比ADM232AARW)
設計說明
The ADM231LAR generates its bipolar RS-232 levels from one 5 V rail through on-board DC-DC converters, but the interface still requires external charge-pump capacitors. Use the 1 uF capacitor value identified in the verified feature summary and follow the manufacturer layout for placement and connection. Keep supply-return routing compact and treat the charge-pump node as a noisy conductor in layout reviews; incorrect capacitor connection can prevent the transmitter from reaching the documented 9 V output swing.
Do not substitute a 16-pin DIP transceiver directly for this 16-lead SOIC part because the lead pitch, body dimensions, and PCB land pattern differ. For a repair, inspect the existing board for the analog power ground, charge-pump capacitor positions, receiver inputs, and shutdown routing before installing a replacement. For a redesign, overlay the complete manufacturer pinout of the selected alternative on the original footprint and confirm every no-connect and shutdown-related pin rather than relying only on package dimensions.
The obsolete status is the primary sourcing risk: one distributor listing reports inventory of 15,600 units and a price of 3.79 USD as of 2026-10-30, but that stock may not be factory-new or traceable. Require lot traceability, manufacturer labeling, date-code review, and counterfeit-screening controls. Also do not assume that any RS-232 transceiver in a 16-lead SOIC package is interchangeable; the ADM231LAR's shutdown behavior, receiver activity during shutdown, and charge-pump implementation must be checked against the chosen replacement.
RS-232 links are unbalanced and susceptible to ground offsets and externally induced noise. The verified 30 V receiver input rating provides input-voltage tolerance, but it does not establish system-level ESD, surge, or isolation performance. Keep the interface ground connected according to the equipment grounding strategy, provide the required protection devices, and avoid long unprotected cable runs. These checks are particularly important where the ADM231LAR links equipment separated by different power-supply earth potentials.
合規資訊
The provided excerpts identify a comparison with RoHS and REACH status but do not state the ADM231LAR's compliance values. These fields therefore remain unknown. AEC-Q100 is treated as not applicable because this is a legacy communications interface IC and no automotive qualification is documented in the supplied data.
