MAX487ESA+ - Low-Power Slew-Rate-Limited RS-485/RS-422 Transceiver | Analog Devices
MPN: MAX487ESA+ ✓ AktifMAX487ESA+ Ringkasan
An RS-485 transceiver is a differential line driver/receiver that translates logic-level UART signals to a robust differential signal capable of being transmitted over long cables in electrically noisy environments. RS-485 supports multi-drop configurations of up to 32 transceivers on a single twisted pair, enabling half-duplex or full-duplex communication over distances up to 1200 m. RS-485 transceivers belong to the broader interface IC category within power management and communication ICs, and are standardized under TIA-485 (formerly EIA-485).
Key features include slew-rate-limited driver outputs that reduce EMI and reflections on unterminated or improperly terminated cables, true fail-safe receiver inputs that guarantee a known output state when the bus is idle or shorted, and a low-current shutdown mode that places the device in <0.1 µA quiescent for power-saving operation. The MAX487ESA+ carries ±15 kV HBM ESD protection on the bus pins, providing robust tolerance to electrostatic discharge events during handling and field installation.
The MAX487ESA+ integrates a complete half-duplex RS-485 link layer with internal cable termination management through slew-rate control rather than discrete termination. Its 5V single-supply operation simplifies power architecture in industrial 24V-rail-derived systems, and its robust differential signaling supports industrial control, building automation, and point-of-sale applications.
Typical applications include industrial fieldbus networks (Modbus, Profibus), HVAC building automation systems, motor control encoder feedback, point-of-sale (POS) terminals, security system intercom panels, and remote utility metering. The MAX487ESA+ pinout and protocol match the broader MAX481/MAX483/MAX485/MAX487/MAX1487 family, allowing drop-in upgrades and obsolescence mitigation across existing designs.
Design considerations: include a 100 nF decoupling capacitor close to VCC, place a 120 Ω termination resistor across the differential pair only at the cable ends, and ensure the cable shield is grounded at one end only to suppress ground loops. The DE and RE pins control driver/receiver direction; when using half-duplex, tie DE and /RE together with a single GPIO line.
This page synthesizes distributor inventory, parametrically matched drop-in alternatives from the MAX48x family and competitive second sources, and practical design notes that go beyond what the manufacturer datasheet alone provides.
Alternatif penggantian untuk MAX487ESA+ — paket yang sama, pin-pada-pin kompatibel. Bagian paket yang berbeda memerlukan kerja ulang PCB diabaikan.
Variasi di dalam seri ini
Model-series yang sama yang kompatibel dengan penggantian MAX487ESA+ (sama faktor bentuk dan footprint) — berbeda di dalam Package, Data Rate, RoHS Status, Supply Voltage.
MAX487ESA+T
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
MAX485ESA+
✅ Drop-InKontak untuk harga
Lihat Datasheet →MAX481ESA+
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
MAX487CSA+
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
MAX487EESA+
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
SN65HVD72DR
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
ST3485EIDT
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
ISL8487EIBZ
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
MAX487ESA+ Spesifikasi
| Fungsi | Transceiver |
| Protocol | RS-422, RS-485 |
| Number of Drivers/Receivers | 1/1 |
| Duplex | Half |
| Tegangan Pemuat | 4.75 V to 5.25 V |
| Laju Data | 250 kbps |
| Supply Current (unloaded/loaded) | 120 µA to 500 µA |
| Shutdown Supply Current | 0.1 µA (typical) |
| ESD Protection (HBM, bus pins) | ±15 kV |
| Slew-Rate Limited | Yes |
| Suhu Kerja | -40 °C to +85 °C |
| Paket | 8-SOIC (NS) |
| Tipe Mounting | Surface Mount |
| Jumlah Pin | 8 |
| Lead-Free / RoHS | Lead-free, RoHS compliant |
Konfigurasi Pin MAX487ESA+
| Pin produk 1 | RO — Receiver Output (logic-level, push-pull) |
| Pin produk 2 | /RE — Receiver Enable (active low; logic low enables RO) |
| Pin produk 3 | DE — Driver Enable (logic high enables differential driver output) |
| Pin produk 4 | DI — Driver Input (TTL/CMOS logic input) |
| Pin produk 5 | GND — Ground |
| Pin produk 6 | A — Driver Output / Receiver Input, non-inverting (Y on full-duplex) |
| Pin produk 7 | B — Driver Output / Receiver Input, inverting (Z on full-duplex) |
| Pin produk 8 | VCC — 5V Supply (4.75V to 5.25V) |
Aplikasi Umum
MAX487ESA+ cocok untuk 6 aplikasis: Industrial Fieldbus Networks, Building Automation and HVAC, Point-of-Sale (POS) Terminals, Motor Control and Encoder Feedback, Security and Intercom Systems, Remote Utility Metering.
Industrial Fieldbus Networks
The MAX487ESA+ is widely deployed in industrial fieldbus networks running Modbus RTU, DMX512, or proprietary half-duplex protocols over a single shielded twisted pair. Its 250 kbps slew-rate-limited driver eliminates the need for discrete termination while reducing EMI on long cable runs, which is critical for industrial installations up to 1200 m. Place 120 Ω termination only at the cable ends and tie DE and /RE to a single GPIO line for direction control.
Direkomendasikan
Building Automation and HVAC
Building automation controllers use the MAX487ESA+ on RS-485 links between HVAC thermostats, VAV box actuators, and centralized building management systems. The 120 µA unloaded supply current keeps power budget low for ceiling-mounted controllers, and the small SOIC-8 footprint suits compact PCB assemblies. With ±15 kV HBM ESD tolerance on the bus pins in the related E-variant, the part tolerates handling during installation.
Direkomendasikan
Point-of-Sale (POS) Terminals
POS terminal daisy chains use the MAX487ESA+ to interconnect cash drawer controllers, receipt printers, and customer displays over a single RS-485 link inside retail enclosures. The 0.1 µA shutdown mode reduces idle power during POS sleep states, extending battery life on mobile terminals. The half-duplex topology minimizes cable count inside congested retail enclosures where space is at a premium.
Direkomendasikan
Motor Control and Encoder Feedback
Servo drives and stepper motor controllers use the MAX487ESA+ to read encoder position feedback from distributed motor nodes. The 250 kbps data rate accommodates typical quadrature encoder streams at high RPM, while slew-rate-limited outputs reduce conducted emissions that could disturb adjacent analog feedback channels. The industrial -40 °C to +85 °C temperature rating ensures reliable operation inside sealed motor housings.
Direkomendasikan
Security and Intercom Systems
Multi-building intercom and access-control panels use the MAX487ESA+ to bridge card readers, door controllers, and central access servers over RS-485. Fail-safe receiver inputs guarantee a defined logic output during cable faults, preventing doors from locking or unlocking spuriously. The 5V single-supply operation simplifies power tree design in PoE-powered intercom stations.
Direkomendasikan
Remote Utility Metering
Utility metering networks use the MAX487ESA+ to daisy chain electricity, water, and gas meters back to a concentrator over several hundred meters of outdoor cable. Low quiescent current extends battery life in meter endpoints, and the -40 °C to +85 °C industrial temperature grade handles unheated outdoor enclosures. Multi-drop support accommodates dozens of meters on one shared bus.
Direkomendasikan
Ringkasan Produk Direkomendasikan
Data referensi engineering untuk MAX487ESA+ — pembandingan, panduan desain, dan informasi konformitas.
Panduan Pemilihan
Pembandingan dengan Alternatif
| Parameter Umum | Produk Ini | MAX487ESA+T | MAX485ESA+ | MAX487EESA+ | SN65HVD72DR | ST3485EIDT |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Texas Instruments | STMicroelectronics |
| Package | SOIC-8 | SOIC-8 | SOIC-8 | SOIC-8 | SOIC-8 | SOIC-8 |
| Supply Voltage | 4.75V to 5.25V | 4.75V to 5.25V | 4.75V to 5.25V | 4.75V to 5.25V | 3.0V to 3.6V | 3.0V to 3.6V |
| Data Rate | 250 kbps | 250 kbps | 2.5 Mbps | 250 kbps | 250 kbps | 12 Mbps |
| Slew-Rate Limited | Yes | Yes | No | Yes | Yes | Yes |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| Shutdown Current | 0.1 uA | 0.1 uA | N/A (no shutdown) | 0.1 uA | 1 uA | 1 uA |
Diferensiator Kunci
- Slew-rate-limited driver reduces EMI on unterminated cables (vsMAX485ESA+)
- Integrated 0.1 µA shutdown mode cuts idle power by 1000x (vsMAX485ESA+)
- Same SOIC-8 pinout as MAX485ESA+ for drop-in fieldbus upgrades (vsMAX485ESA+)
- Single 5V supply eliminates dual-rail complexity (vsMAX13487EESA+T)
Catatan Desain
Place a 100 nF X7R ceramic decoupling capacitor within 5 mm of the VCC pin (pin 8) and another between GND (pin 5) and the ground plane. For multi-transceiver nodes, add a bulk 10 µF tantalum or ceramic cap on the same 5V rail. Keep the differential pair (A/B) routed as a 100 Ω differential transmission line over a continuous ground plane; this minimizes reflections and EMI.
Do not place 120 Ω termination resistors at every node. RS-485 termination should ONLY be placed at the two cable ends to avoid loading the bus. Leaving middle nodes unterminated lets reflections die out at the ends without overshoot. For multi-drop networks with stubs, keep stubs shorter than 1/10 of the signal rise time for clean signaling.
Although the MAX487 supports a 0.1 µA shutdown mode, designers often forget that DE must be logic low to achieve true shutdown current. If DE floats or sits high, the device draws 100s of µA continuously. Use a 100 kΩ pull-down on DE when shutdown mode is desired but the host MCU GPIO is not driven.
The MAX487ESA+ provides slew-rate-limited driver outputs that reduce high-frequency content. Use this part when cables are unterminated, stub lengths are non-trivial, or when EMI compliance is a concern. If higher data rates (above 250 kbps) are needed, switch to the MAX485ESA+ which lacks slew-rate limiting but supports 2.5 Mbps.
Informasi Konformitas
Lead-free and RoHS compliant per '+' suffix per manufacturer datasheet. Conflict-minerals compliance per manufacturer declaration. Not AEC-Q100 qualified - use automotive-grade transceiver for vehicle networks.
