MC1489AM - Quad EIA-232D Receiver | onsemi | SOIC-14
MPN： MC1489AM ✓ 啟用中MC1489AM 概覽
An EIA-232D line receiver belongs to the interface IC hierarchy, where it sits between a physical communication port and digital logic. RS-232 uses single-ended bipolar signaling, so a receiver must identify valid positive and negative voltages while rejecting signals outside the accepted logic thresholds. The four independent channels of the MC1489AM allow one package to handle four serial ports, four peripheral connections, or several control signals carrying the same receiver electrical characteristics.
The primary electrical feature is its 3.0 kΩ to 7.0 kΩ input resistance. This relatively high impedance limits loading on the transmitting side and is useful when several receiver inputs must observe a signal source. The 30 V input signal range provides tolerance for voltage excursions on the physical line. Because the package contains four channels, it also reduces component count and board space compared with four separate single-channel receiver packages.
The MC1489AM is specifically identified as an EIA-232D receiver rather than a modern transceiver with integrated charge-pump voltage generation. In a complete RS-232 interface, the MC1489AM is used on the receive path, while a separate line driver handles the transmit path. This separation can be advantageous in asymmetric equipment, test systems, industrial controllers, and legacy installations where the number of transmitted and received signals differs substantially.
Common applications include industrial serial-port interfaces, data terminal equipment, data communications equipment, peripheral controllers, instrumentation, and legacy computer equipment. Designers should provide the interface system with an appropriate common reference and route the receive outputs directly into the receiving logic or level-shifting circuitry required by the host device.
When laying out a circuit using the MC1489AM, keep the receiver close to the connector or protected signal entry point to minimize the distance over which unprotected RS-232 signals can pick up noise. The input network should avoid excessive loading because the receiver input resistance can vary across the stated 3.0 kΩ to 7.0 kΩ range. Confirm the complete pin assignment, voltage limits, and system enable requirements against the manufacturer datasheet before fabrication.
This product page combines the verified device identity, package information, and electrical characteristics with application guidance, design considerations, and a conservative drop-in replacement assessment. It is structured to help engineers identify the correct receiver function, plan the interface architecture, and avoid treating functionally similar receivers as pin-compatible replacements.
直接替換替代品，適用於 MC1489AM — 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。
此系列的變體
與下列產品可直接替換的同系列型號： MC1489AM （相同外形與佔位） — 差異在於 Input Resistance, Interface Standard, Mounting Type, Package, Receiver Type.
MC1489AM 規格
| Receiver Type | Quad line receiver |
| Number of Channels | 4 channels |
| Interface Standard | EIA-232D |
| Input Resistance | 3.0 kΩ to 7.0 kΩ |
| Input Signal Range | 30 V |
| 封裝 | 14-pin SOIC |
| 腳位數 | 14 pins |
| 安裝類型 | Surface mount |
MC1489AM 14-pin soic 腳位配置指南
MC1489AM（14-pin 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： MC1489AM.
請參閱 資料表 以查看完整腳位配置。
典型應用
MC1489AM 適用於 6 應用s: Industrial Serial Port Receive Interface, Data Terminal Equipment Interface, Legacy Computer Peripheral Connection, Instrumentation Control Interface, Communication Equipment Interface, Asymmetric RS-232 Port Expansion.
Industrial Serial Port Receive Interface
The MC1489AM fits industrial RS-232 receive paths because it combines four receiver channels in one 14-pin SOIC and presents an input resistance of 3.0 kΩ to 7.0 kΩ. Each channel can receive a separate EIA-232D signal from an operator interface, controller, or service port. The 30 V input range provides additional margin for the bipolar voltage environment associated with the physical line. Place the device near the connector or protected interface entry point, and connect each receiver output to the appropriate logic input using the manufacturer-defined pinout.
推薦
Data Terminal Equipment Interface
The MC1489AM is well suited to the receive side of data terminal equipment because its four monolithic channels can consolidate multiple RS-232 inputs without four separate receiver packages. Its 3.0 kΩ to 7.0 kΩ input resistance limits loading, while the 30 V input range accommodates the bipolar signaling expected on an EIA-232D line. The design must include a separate line driver for outbound data and should use the manufacturer pin-description table to route the four outputs and any enable or common pins correctly.
推薦
Legacy Computer Peripheral Connection
The MC1489AM can replace four discrete RS-232 receiver circuits in a legacy peripheral controller. Its 14-pin SOIC package provides a compact implementation, and the four-channel arrangement allows status, control, and data signals with compatible receiver characteristics to share one IC. The receiver-only architecture is particularly useful when the legacy equipment receives more channels than it transmits. Add appropriate connector protection and verify that the host logic voltage matches the receiver output levels specified in the ON Semiconductor datasheet.
推薦
Instrumentation Control Interface
The MC1489AM is appropriate for receive-only control connections in instrumentation systems that use EIA-232D command and response signals. Four channels can handle multiple measurements, status indicators, or remote commands while keeping the receiver count low. The input resistance of 3.0 kΩ to 7.0 kΩ reduces source loading, and the 30 V input range is useful for a bipolar line interface. The circuit should include suitable surge and ground-path protection appropriate to the installation environment rather than assuming the receiver alone provides complete connector protection.
推薦
Communication Equipment Interface
The MC1489AM supports communication equipment that receives four RS-232 lines from a host, modem, or peripheral while transmitting on a smaller number of channels. Its monolithic quad-receiver implementation reduces the number of devices required on the receive side and offers a defined 3.0 kΩ to 7.0 kΩ input impedance. The 14-pin SOIC is practical for conventional surface-mounted boards. System designers should maintain controlled return paths, route receive traces away from switching nodes, and use a separate EIA-232D line driver for every required transmit channel.
推薦
Asymmetric RS-232 Port Expansion
The MC1489AM is ideal when a system needs more receive channels than transmit channels. Four dedicated receivers can be installed in a single SOIC-14 package, while the transmit side uses only the required number of line drivers. This arrangement avoids adding unused transmitter circuitry to every port and provides a clear separation between receive and transmit signal paths. Use the exact manufacturer pinout to assign channels, connect the device supply and common reference, and confirm that the downstream logic uses compatible receiver output levels.
推薦
推薦產品摘要
工程參考資料，適用於 MC1489AM — 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 | MC1489AN |
|---|---|---|
| Package | SOIC-14 | SOIC-14 |
| Brand | onsemi | onsemi |
| Receiver Channels | 4 channels | 4 channels |
| Interface Standard | EIA-232D | EIA-232D |
| Function | Receiver only | Receiver only |
主要差異化特點
- Four receive channels in one 14-pin package (對比MC1489AN)
- Dedicated receiver-only architecture (對比MC1489AN)
- Documented high input impedance and 30 V input range (對比MC1489AN)
設計說明
Place the MC1489AM close to the RS-232 connector or protected interface entry point. Unprotected bipolar signals can pick up noise when routed across a large PCB area, so minimize receiver trace length and place any intended protection network between the connector and the receiver inputs. Keep receive traces away from switching-power nodes, relay contacts, high-current motor wiring, and other noisy conductors. Use a continuous ground reference and return the cable shield according to the equipment's grounding strategy.
Do not treat every quad RS-232 receiver as a drop-in replacement. The TI MC1489 family comparison notes that a functionally comparable device may have a different pinout. Before substituting MC1489AN or another quad receiver, compare every pin, including receiver inputs and outputs, enable functions, supply connections, and common pins. Also confirm the logic thresholds and supply voltage. A package with 14 leads is not sufficient evidence of pin compatibility, and PCB artwork changes may be required if the assignments differ.
Design the receive path around the specified 3.0 kΩ to 7.0 kΩ input resistance rather than a single nominal value. Use the lower resistance when calculating worst-case loading on the line source, and ensure that protection components do not create excessive capacitance or leakage at the receiver input. The 30 V input signal range should not be treated as permission to remove external protection. Validate the complete interface against the system’s surge, ESD, and fault-voltage requirements.
The MC1489AM is a receiver-only IC, so it does not require the charge-pump circuitry used by a combined RS-232 transceiver. Nevertheless, its supply and common connections must meet the limits and sequencing requirements in the manufacturer datasheet. Decouple the supply close to the device using the recommended capacitor arrangement. If another device in the system generates positive and negative RS-232 levels, verify startup and shutdown behavior so the receiver is not exposed to an invalid interface state.
合規資訊
The MC1489AM is an industrial legacy interface IC rather than an automotive-qualified device. RoHS, REACH, lead-free, halogen-free, and conflict-minerals status require confirmation from current manufacturer documentation.