ISL8490IP - 5Mbps RS-485/RS-422 Transceiver | Renesas
料号： ISL8490IP ✗ 停产ISL8490IP 概述
A transceiver is an interface IC that converts digital logic signals into balanced differential signals for reliable communication over noisy or long cable runs. In the hierarchy, the ISL8490IP is a line transceiver, a type of interface IC and communications semiconductor. RS-485 supports multiple drivers and receivers on a shared bus, whereas RS-422 commonly uses a dedicated driver and receiver for point-to-point or multidrop networks. This transceiver supports both protocols and therefore provides a useful interface between CMOS/TTL logic and balanced cabling.
The verified headline specifications are a 5 V supply, 5 Mbps maximum data rate, 70 mV receiver hysteresis, 1 driver, 1 receiver, full-duplex operation, and support for RS-422 and RS-485. These parameters place the part in the low-power, high-speed or slew-rate-limited transceiver category described by the manufacturer documentation. The 8-pin PDIP format also permits conventional through-hole PCB assembly rather than requiring a fine-pitch surface-mount land pattern.
Technically, the balanced driver and receiver provide noise immunity over longer interconnects than ordinary single-ended logic. Receiver hysteresis helps distinguish signaling states in the presence of noise, while the 5 Mbps capability supports communication rates beyond the slow speeds commonly used by legacy RS-485 systems. Because the exact input capacitance, output timing, supply-current limits, and slew-rate settings are not included in the supplied verified excerpts, design engineers should confirm them in the manufacturer datasheet before finalizing timing, termination, and decoupling.
Typical uses include industrial controllers, building automation equipment, data acquisition systems, instrumentation, industrial networking equipment, and embedded control links. For an RS-485 bus, the circuit requires suitable line termination and biasing. For RS-422, driver and receiver connections should follow the source and destination topology specified by the system architecture rather than being treated as a multi-drop RS-485 bus.
The principal design consideration is signal integrity at 5 Mbps. Layout should minimize the distance between the transceiver, protection devices, connector, and differential pair, while keeping the two conductors of each balanced pair closely coupled. Decoupling close to the supply pin, controlled ground return paths, and appropriate surge protection help maintain reliable operation in industrial environments.
This page consolidates the verified distributor and manufacturer-document information with lifecycle status, procurement guidance, application fit, package details, and honest replacement limitations. It distinguishes confirmed facts from specifications that still require verification from the full Renesas datasheet.
直接替换替代料： ISL8490IP ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： ISL8490IP （相同外形与封装尺寸） ——差异在于 Number of Drivers, Number of Receivers, Package, Product Type.
ISL8480IP
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
ISL8481IP
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
ISL8482IP
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
ISL8491IP
✅ 直接替换 ⚠️ 规格未核验联系询价
查看数据手册 →ISL8492IP
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
ISL8490IP 规格参数
| Product Type | RS-485/RS-422 transceiver |
| 电源电压 | 5 V |
| Maximum Data Rate | 5 Mbps |
| Number of Drivers | 1 |
| Number of Receivers | 1 |
| Duplex Mode | Full duplex |
| Supported Protocols | RS-422 and RS-485 |
| Receiver Hysteresis | 70 mV |
| 工作温度范围 | -40°C to +85°C |
| 封装 | 8-PDIP |
| 安装类型 | Through-hole |
| Packaging Type | Tube/Rail |
| Logic Level | CMOS-compatible |
| Differential Signal Type | Balanced |
ISL8490IP 8-pdip 引脚配置指南
ISL8490IP（8-pdip 封装）的引脚配置。 引脚编号、功能和连接图在制造商数据手册中定义。请参阅该手册以了解确切的封装尺寸和焊接指南。
暂无详细引脚数据： ISL8490IP.
请参阅 数据手册 以查看完整引脚配置。
典型应用
ISL8490IP 适用于 6 应用s: Industrial RS-485 Control Networks, Industrial Automation and Factory Equipment, Building Automation and HVAC Equipment, Data Acquisition and Instrumentation, RS-422 Point-to-Point Communication, Legacy Communication Equipment Maintenance.
Industrial RS-485 Control Networks
The ISL8490IP fits legacy industrial control links that use a 5 V supply, balanced RS-485 signaling, and a maximum data rate of 5 Mbps. Its one-driver, one-receiver arrangement provides a full-duplex interface between controller logic and a field bus or remote I/O module. The 8-PDIP package also suits through-hole industrial boards that are difficult to re-layout. Because the device is obsolete, engineers should reserve it primarily for maintenance of proven equipment and verify availability before committing to new production.
Industrial Automation and Factory Equipment
Factory machinery commonly distributes control and diagnostic information over balanced differential buses, where the ISL8490IP's RS-485 support and 5 Mbps data rate are useful. The transceiver can connect a controller or data-acquisition unit to motor controls, sensors, remote I/O, or supervisory equipment while reducing susceptibility to common-mode noise. Its documented -40°C to +85°C operating range supports industrial temperature conditions. Board-level surge and ESD protection should nevertheless be selected separately for the installation environment.
Building Automation and HVAC Equipment
The ISL8490IP is applicable to building-control panels, HVAC controllers, and supervisory systems that distribute commands over RS-485 or RS-422 links. Balanced differential signaling is valuable when cables pass near motors, lighting equipment, and other electrical noise sources, while the 5 Mbps ceiling supports more demanding control traffic than low-speed legacy buses. The through-hole 8-PDIP format is useful when servicing an existing controller. For new equipment, lifecycle availability and verified electrical equivalence must be checked before the part is approved.
Data Acquisition and Instrumentation
The ISL8490IP can bridge laboratory or field instrumentation to a host computer through a balanced RS-485 network. Its single transmitter and receiver suit point-to-point or bus-based acquisition, and the 5 Mbps maximum rate provides ample margin for many sensor and monitoring data streams. Differential signaling helps preserve data integrity over longer cable runs. Engineers should confirm receiver thresholds, timing margins, input capacitance, and cable-length limits in the full manufacturer datasheet before selecting termination and topology.
RS-422 Point-to-Point Communication
The ISL8490IP supports RS-422 in addition to RS-485, making it appropriate for dedicated links between a transmitter and receiver when a multidrop bus is unnecessary. Full-duplex capability allows send and receive paths to operate independently where the system architecture provides separate conductors for each direction. The 5 V supply and 5 Mbps capability are compatible with many legacy logic systems, but exact driver impedance, output levels, and propagation timing must be checked against the verified datasheet before sign-off.
Legacy Communication Equipment Maintenance
The obsolete ISL8490IP is most practical for repairing or extending equipment whose PCB already uses the 8-PDIP footprint and whose original design depends on the documented electrical behavior. It can avoid a risky board redesign when a qualified replacement has not yet been validated. Maintenance teams should match the full MPN, inspect device markings, confirm supply and pin compatibility, and document the substitution process. Because pricing and lifecycle supply are uncertain, stocking a small number of traceable parts may be more practical than assuming long-term availability.
工程参考数据： ISL8490IP ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | ISL8480IP | ISL8481IP | ISL8482IP | ISL8491IP | ISL8492IP |
|---|---|---|---|---|---|---|
| Package | 8-PDIP | 8-PDIP | 8-PDIP | 8-PDIP | 8-PDIP | 8-PDIP |
| Brand | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics |
关键差异点
- Five-megabit interface capability （对比 ISL8480IP)
- Documented receiver hysteresis （对比 ISL8481IP)
- Full-duplex RS-485 and RS-422 support （对比 ISL8482IP)
- Through-hole PCB compatibility （对比 ISL8491IP)
设计说明
Route the RS-485 and RS-422 signals as a closely coupled differential pair with continuous ground reference, and minimize the distance from the ISL8490IP to the connector and any series protection components. Avoid routing the pair through switching-power or high-current motor nodes. The transceiver supports 5 Mbps, so uncontrolled stubs, long breaks in the ground path, and asymmetric trace geometry can reduce signal margin even when the logic-side wiring is correct.
Do not treat RS-422 point-to-point wiring and RS-485 multidrop wiring as electrically interchangeable. RS-485 may require bias resistors to establish a stable idle state when multiple receivers are connected, while termination belongs at the physical ends of the bus. Confirm whether the DE and RE pins are exposed in the design and control them properly before asserting the driver. Always use the manufacturer pinout because the supplied excerpts do not provide verified numbered pin assignments.
Place the required supply-decoupling capacitor immediately adjacent to the transceiver’s power and ground pins, and keep the return current path short and continuous. The ISL8490IP is identified as a 5 V low-power device, but its complete supply tolerance and current limits are not present in the supplied excerpts. Verify those values in the manufacturer datasheet and ensure the upstream 5 V rail has adequate transient response for the transceiver and any protection circuitry.
The part is marked obsolete, so inventory condition and provenance can vary. Purchase by the exact ISL8490IP MPN, request lot traceability where available, and perform incoming inspection before installation. For maintenance work, compare the replacement’s pinout, logic levels, receiver thresholds, propagation delay, output impedance, and supply requirements rather than relying only on the RS-485 and RS-422 labels.
合规信息
The supplied verified excerpts do not explicitly state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. The product was published in 2003, but publication date does not establish regulatory compliance.
