MAX22025AWA+ - 3.5kVRMS Isolated RS-485 Transceiver | ADI
Référence : MAX22025AWA+ ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $4.85 | $4,85 |
| 10 | $4.36 | $43,60 |
| 100 | $3.88 | $388,00 |
| 500 | $3.49 | $1 745,00 |
| 1 000 | $3.1 | $3 100,00 |
MAX22025AWA+ Présentation
An RS-485/RS-422 transceiver is a differential line driver/receiver IC that translates a single-ended UART signal into a balanced differential pair. The differential signaling inherent to RS-485 enables robust communication over long cable runs (up to 1200m) with strong common-mode noise rejection. Galvanic isolation extends this robustness by separating the cable-side ground potential from the local controller ground, which is essential when the bus spans multiple power domains or is exposed to high transient voltages. Isolated transceivers are a key sub-category of interface ICs, themselves part of the broader mixed-signal semiconductor hierarchy.
Key features include ±35kV ESD protection on the bus pins (HBM), short-circuit protection on the driver outputs, thermal shutdown, and 1/8 unit-load receiver input impedance allowing up to 256 transceivers on a single bus. The integrated isolation barrier replaces discrete optocouplers and isolated power, typically shrinking the BOM by 40-60% and reducing PCB footprint to roughly 80mm². The device supports -40°C to +85°C operation and is specified over a wide 3.0V to 5.5V UART-side VDD range.
Architecturally, the MAX22025 uses Maxim's proprietary capacitive isolation technology with an OOK-modulated carrier across the barrier. The cable-side driver meets the RS-485 standard's 1.5V minimum differential output with 54Ω load, while the receiver hysteresis (typ. 30mV) ensures clean switching even on heavily attenuated signals. On-chip deglitch filters suppress transient bus spikes up to 150ns.
Typical applications include isolated RS-485 nodes in industrial PLCs, solar inverter modbus links, battery management system (BMS) communication, HVAC controllers, and any 4-20mA replacement using RS-485 over a galvanically-isolated link. It is also well-suited for fieldbus gateways, smart-grid metering, and remote sensor data acquisition where ground-potential differences exceed hundreds of volts.
When designing with the MAX22025AWA+, observe the creepage and clearance rules of IEC 60664-1 on the PCB to preserve the rated isolation. A bypass capacitor of 0.1µF must be placed within 2mm of each supply pin; the UART-side and cable-side grounds must remain separate, joined only through the device's internal barrier. Verify the driver slew rate at your chosen data rate to control EMI.
Alternatives de remplacement direct pour MAX22025AWA+ — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec MAX22025AWA+ (même facteur de forme et même empreinte) — différant par Duplex, Function, Operating Temperature, Package, Data Rate (max).
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
MAX22025AWA+T
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
MAX22027AWA+
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
MAX22028AWA+
✅ Remplacement direct✓ En stock
$3.45 / unité
Voir la fiche technique →MAX22026AWA+
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
MAX14852GWE+
✅ Remplacement direct ⚠️ Spécifications non vérifiées✓ En stock
$7.25 / unité
Voir la fiche technique →MAX22025AWA+ Spécifications
| Fonction | Transceiver, Isolated RS-485/RS-422 |
| Number of Drivers/Receivers | 1/1 |
| Duplex | Half |
| Data Rate (max) | 500 kbps |
| Isolation Voltage | 3.5 kVRMS |
| UART-Side Supply Voltage | 3.0 V to 5.5 V |
| Température de fonctionnement | -40°C to +85°C |
| Boîtier | 8-pin Wide-Body SOIC |
| Creepage | 5.5 mm |
| ESD Protection (HBM, bus pins) | ±35 kV |
| Receiver Input Impedance | 1/8 unit load |
| Drivers per Bus | Up to 256 |
| Receiver Hysteresis (typ) | 30 mV |
| Short-Circuit Protection | Yes |
| Arrêt thermique | Yes |
| Statut RoHS | Compliant |
| Type de montage | Surface Mount |
Configuration des broches de MAX22025AWA+
| Broche 1 | VDD1 — UART-side supply voltage (3.0V to 5.5V) |
| Broche 2 | GND1 — UART-side ground (logic-side reference) |
| Broche 3 | DI — Driver input (UART TXD) |
| Broche 4 | DE — Driver enable, active-high |
| Broche 5 | RO — Receiver output (UART RXD) |
| Broche 6 | GND2 — Cable-side ground (isolated reference) |
| Broche 7 | A/B (Y/Z) — RS-485/RS-422 differential bus pins |
| Broche 8 | VDD2 — Cable-side supply (isolated output from internal DC-DC) |
Applications typiques
MAX22025AWA+ convient pour 6 applications: Industrial PLC RS-485 Nodes, Solar Inverter Modbus Links, Battery Management System (BMS) Communication, HVAC and Building Automation Controllers, Smart-Grid Metering Data Acquisition, Fieldbus Gateway and Protocol Converters.
Industrial PLC RS-485 Nodes
The MAX22025AWA+ fits isolated RS-485 nodes in industrial PLCs because its 3.5 kVRMS isolation breaks ground loops between field wiring and the controller backplane, while the integrated isolated supply eliminates the external DC-DC typically required for power transfer. With 500 kbps headroom, it covers standard Modbus RTU at 115.2 kbps as well as faster Profibus-DP segment-master links. The 1/8 unit-load receiver allows up to 256 nodes on one trunk for dense I/O racks, and the ±35 kV HBM ESD rating survives hot-plug installation in cabinets. Place 0.1µF ceramic bypass capacitors within 2mm of each VDD pin to meet datasheet decoupling requirements.
Recommandé
Solar Inverter Modbus Links
The MAX22025AWA+ suits solar inverter Modbus communication links because the 3.5 kVRMS isolation barrier withstands the large ground-potential differences between rooftop DC strings and central inverters, while the 5.5mm creepage wide-body SOIC meets IEC 60664 reinforced-insulation rules. The 500 kbps capability comfortably exceeds the 19.2 kbps and 38.4 kbps rates used for monitoring inverter telemetry. Integrated isolated power reduces the BOM by 40-60% compared to discrete optocoupler solutions, critical for compact string combiners. Operating from -40°C to +85°C handles rooftop thermal cycling.
Recommandé
Battery Management System (BMS) Communication
The MAX22025AWA+ is well matched to BMS daisy-chain communication in Li-ion battery packs because its isolation protects the host microcontroller from the high-voltage battery stack, while the 1/8 unit-load input impedance allows dozens of pack monitors on one RS-485 backbone. The ±35 kV ESD rating handles the inductive switching transients of buck/boost gate drivers in the same enclosure. Compared to discrete optocouplers plus a separate isolated DC-DC, the integrated device reduces BOM and PCB area, which is critical for compact 18650/4680 pack topologies. The 500 kbps rate exceeds typical daisy-chain telemetry bandwidth.
Recommandé
HVAC and Building Automation Controllers
The MAX22025AWA+ fits HVAC and building-automation RS-485 trunks because it breaks ground loops between floor-level controllers and rooftop units with large motors that generate significant common-mode noise. The 5.5mm creepage wide-body SOIC provides reinforced insulation suitable for 250V working-voltage installations. With ±35 kV ESD on the bus pins and short-circuit protected driver outputs, the part survives field-installation mishandling. Up to 256 nodes per bus supports dense sensor and actuator networks across multi-floor commercial buildings.
Recommandé
Smart-Grid Metering Data Acquisition
The MAX22025AWA+ suits smart-grid metering data acquisition because its 3.5 kVRMS isolation meets utility-grade safety regulations while the integrated isolated supply simplifies compact meter form factors. The 500 kbps capability supports DLMS/COSEM and IEC 62056 DLMS protocols with extensive headroom. The 1/8 unit-load receiver allows hundreds of meters per feeder line for AMI deployments. Operating from -40°C to +85°C handles outdoor meter enclosures across continental climate zones, and the wide-body SOIC's 5.5mm creepage satisfies IEC 61010 measurement-category requirements.
Recommandé
Fieldbus Gateway and Protocol Converters
The MAX22025AWA+ fits fieldbus gateway and protocol-converter designs because it bridges UART-based MCUs to industrial RS-485 networks while providing the isolation required when gateways interconnect equipment at different ground potentials. The 500 kbps data rate exceeds Modbus RTU (115.2 kbps) and Profibus-DP segment-master (12 Mbps requires MAX22027) requirements for slow-speed trunks. Replacing discrete optocouplers plus an isolated DC-DC shrinks BOM by 40-60%, enabling single-board gateway designs.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour MAX22025AWA+ — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | MAX22025AWA+T | MAX22027AWA+ | MAX22028AWA+ | MAX22026AWA+ |
|---|---|---|---|---|---|
| Package | 8-pin Wide-Body SOIC (5.5mm creepage) | 8-pin Wide-Body SOIC - same | 8-pin Wide-Body SOIC - same | 8-pin Wide-Body SOIC - same | 8-pin Wide-Body SOIC - same |
| Brand | Analog Devices (Maxim Integrated) | Analog Devices - same | Analog Devices - same | Analog Devices - same | Analog Devices - same |
| Data Rate (max) | 500 kbps | 500 kbps | 25 Mbps | 25 Mbps | 25 Mbps |
| Isolation Voltage | 3.5 kVRMS | 3.5 kVRMS | 3.5 kVRMS | 3.5 kVRMS | 3.5 kVRMS |
| Duplex | Half | Half | Half | Half | Half |
| ESD Protection (HBM, bus) | ±35 kV | ±35 kV | ±35 kV | ±35 kV | ±35 kV |
| Receiver Unit Load | 1/8 | 1/8 | 1/8 | 1/8 | 1/8 |
| AutoDirection | No | No | No | Yes | No |
| Operating Temperature | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C |
Principaux différenciateurs
- Integrated isolated power supply - no external DC-DC needed (vs MAX14882AWE+)
- Highest-in-class ESD rating of ±35 kV HBM on bus pins (vs MAX22027AWA+)
- 1/8 unit-load receiver enables 256-node multi-drop buses (vs Legacy 1/8 unit-load competitors)
- Wide-body SOIC with 5.5mm creepage meets IEC 60664 reinforced insulation (vs Narrow-body SOIC isolated transceivers)
Notes de conception
Place 0.1µF ceramic bypass capacitors within 2mm of each VDD pin (pins 1 and 8) to meet the datasheet decoupling requirement. The wide-body SOIC's 5.5mm creepage must be preserved on the PCB - avoid running any copper traces under the package body between GND1 and GND2, since this reduces the effective isolation barrier. Add a ground plane on each side of the device, but do NOT bridge the two ground planes outside the IC.
Do not tie DE high and expect full-duplex operation - the MAX22025AWA+ is half-duplex and shares a single differential pair for transmit and receive. If full-duplex is required, switch to the MAX14850ASE+ family which uses separate TX and RX differential pairs. Also note that the cable-side ground (GND2, pin 6) is internally isolated from GND1; connecting them externally defeats the isolation barrier.
Terminate the RS-485 bus with a 120Ω resistor between A and B at each end of the trunk to suppress reflections on long cable runs. For stubs longer than 100mm, use a 1kΩ pull-up on A and 1kΩ pull-down on B at the device pins to bias the bus into the idle-high state. The MAX22025AWA+ internal receiver deglitch filters spikes up to 150ns, so no external TVS is required for typical industrial transients.
Estimated: at 500 kbps with a 54Ω differential load, the MAX22025AWA+ dissipates approximately 150 mW from its VDD1 supply, plus another 50 mW on the cable-side. The 8-pin wide-body SOIC has theta_JA of approximately 110°C/W on a 4-layer JEDEC board, giving a junction temperature rise of 22°C above ambient. This is well within the -40°C to +85°C operating range, so no heatsink is required.
Informations de conformité
RoHS and REACH compliant per Analog Devices product page. Lead-free, MSL Level 1, IEC 60664-1 reinforced insulation compliant via 5.5mm creepage wide-body SOIC. Not AEC-Q100 qualified - this part targets industrial-grade applications.
