ISL83485IBZ-T - 3.3V 10Mbps RS-485/422 Transceiver, 8-SOIC | Renesas
MPN: ISL83485IBZ-T ⚠ Last Time Buy| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.45 | $2.45 |
| 10 | $2.18 | $21.80 |
| 100 | $1.85 | $185.00 |
| 500 | $1.62 | $810.00 |
| 1,000 | $1.4 | $1,400.00 |
| 2,500 | $1.18 | $2,950.00 |
ISL83485IBZ-T Overview
A RS-485/RS-422 transceiver is a physical-layer (PHY) interface IC that converts the single-ended logic-level signals of a UART or microcontroller into the differential voltage swings required for balanced twisted-pair transmission. These transceivers are categorized under interface ICs and, more broadly, under wired-connectivity semiconductors, sitting beneath network controllers and above simple line drivers in the silicon hierarchy. They enable robust, noise-immune communication over long cable runs in electrically harsh environments.
The key features of this part include a wide 3.0V to 3.6V supply range optimized for 3.3V logic systems, 1/8 unit-load receiver input impedance that allows up to 256 transceivers on a single bus, hot-plug circuitry that limits transient bus current during insertion, and a dedicated shutdown pin that drops quiescent current to microamp levels for power-sensitive applications. The 8-SOIC package supports a standard surface-mount footprint and is pin-compatible with industry-standard 3.3V RS-485 parts such as the MAX485 and SN75176B.
The BiCMOS process combines bipolar drive strength on the bus side with CMOS low-power logic, achieving a balance of speed and quiescent consumption that pure-CMOS parts cannot match. With 10Mbps capability, the ISL83485IBZ-T fits high-speed sensor data links, while the part also survives ±15kV HBM ESD strikes per the datasheet, eliminating the need for external TVS protection in most field installations.
Typical applications include industrial fieldbus networks, building automation gateways, security camera RS-485 control links, point-of-sale peripheral connections, and motor-drive feedback loops. In each of these scenarios, the ISL83485IBZ-T serves as the PHY layer between a UART-enabled host and the differential twisted-pair bus.
When designing with this part, provision for a 120 ohm differential termination at each bus end and ensure the shutdown pin is tied high through a pull-up if unused, to avoid floating logic. A small 100nF decoupling capacitor placed within 5mm of the VCC pin is essential for hot-plug transient suppression. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found on a single manufacturer product page.
Drop-in alternatives for ISL83485IBZ-T — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ISL83485IBZ-T (same form factor and footprint).
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ISL83485IBZ-T Specifications
| Function | Transceiver |
| Number of Drivers/Receivers | 1/1 |
| Duplex | Half |
| Protocol | RS-422, RS-485 |
| Data Rate | 10 Mbps |
| Supply Voltage | 3.3 V |
| Supply Voltage Range | 3.0 V to 3.6 V |
| Receiver Input Impedance | 1/8 unit-load (up to 256 nodes) |
| Operating Temperature | -40C to +85C |
| Package | 8-SOIC (IB) 3.9 mm |
| Mounting Type | Surface Mount |
| RoHS Status | ROHS3 Compliant |
| Shutdown Pin | Yes |
| Process Technology | BiCMOS |
ISL83485IBZ-T Pin Configuration
| Pin 1 | RO — Receiver output |
| Pin 2 | RE — Receiver enable, active low |
| Pin 3 | DE — Driver enable, active high |
| Pin 4 | DI — Driver input |
| Pin 5 | GND — Ground |
| Pin 6 | A — Non-inverting differential bus pin (or Y for RS-422) |
| Pin 7 | B — Inverting differential bus pin (or Z for RS-422) |
| Pin 8 | VCC — 3.3V power supply |
Typical Applications
ISL83485IBZ-T is suitable for 6 applications: Industrial RS-485 Fieldbus Networks, Building Automation Gateways, Security Camera PTZ Control Links, Motor Drive Feedback and Encoder Links, Point-of-Sale Peripheral Connectivity, Multi-Drop Sensor Networks.
Industrial RS-485 Fieldbus Networks
The ISL83485IBZ-T is a strong fit for industrial RS-485 fieldbus networks because it operates on a single 3.3V rail and supports 10Mbps data rates, allowing high-speed sensor and actuator links on Modbus RTU, Profibus-DP, and BACnet MS/TP segments. The 1/8 unit-load receiver lets up to 256 transceivers share a single twisted-pair bus, which is essential for factory-floor installations with hundreds of sensor drops. The -40C to +85C industrial temperature range tolerates unconditioned cabinet environments. Placed between a UART-capable host MCU and the differential bus, the part adds 1/8 unit-load fan-out and ±15kV HBM ESD protection per the datasheet, eliminating external TVS in most setups. Trade-off: the Last Time Buy lifecycle requires migration planning.
Recommended
Building Automation Gateways
The ISL83485IBZ-T is well suited to building automation gateways that aggregate HVAC, lighting, and access-control data over RS-485 trunks. Its 10Mbps speed supports real-time BACnet MS/TP and KNX-TP1 segments without bottlenecking controller-to-controller traffic. The BiCMOS drive strength delivers clean differential signaling across the long cable runs typical in commercial buildings, while the shutdown pin reduces standby current to microamp levels, helping gateways meet energy-harvesting or battery-backed operation requirements. Its 8-SOIC footprint matches the MAX3485 family, so designers can swap parts during supply disruptions. Limitation: 3.3V-only supply requires a level shifter if the gateway MCU runs at 1.8V or 5V rails.
Recommended
Security Camera PTZ Control Links
In PTZ camera control networks, the ISL83485IBZ-T provides a robust half-duplex RS-485 link for telemetry, zoom, and pan commands at 10Mbps over long daisy-chained cable runs. The 1/8 unit-load receiver allows up to 256 cameras on a single control bus, suitable for large surveillance installations. Its ±15kV HBM ESD tolerance protects against static discharge during camera installation. The 3.3V supply aligns with modern camera SoCs, eliminating level translation. Compared to slower slew-rate-limited parts, the 10Mbps rate ensures near-instant command response across hundreds of nodes. Design tip: place a 120 ohm termination at each cable end to prevent signal reflection on long runs.
Recommended
Motor Drive Feedback and Encoder Links
The ISL83485IBZ-T is a natural fit for motor-drive feedback loops, where it transmits encoder and resolver data back to a centralized controller over RS-485 at 10Mbps. Its 3.3V supply matches low-voltage DSP and FPGA controllers common in modern servo drives, while the BiCMOS drive delivers clean differential signaling even in the presence of high PWM noise. The half-duplex configuration is ideal for transmit-only or receive-only feedback segments, and the -40C to +85C range covers the operating conditions of industrial cabinet mounting. The 1/8 unit-load receiver lets many drives share a single feedback bus, simplifying cabinet wiring. Compared to discrete optocoupler isolation schemes, the ISL83485IBZ-T saves board area.
Recommended
Point-of-Sale Peripheral Connectivity
Point-of-sale terminals use the ISL83485IBZ-T to connect receipt printers, customer displays, barcode scanners, and cash drawers over RS-485. The 10Mbps data rate supports fast barcode-scanner handshakes and real-time display updates, while the 3.3V supply matches modern POS SoCs. The 8-SOIC footprint and standard pinout let OEMs reuse existing MAX485-based designs without PCB rework. The shutdown pin enables per-port power gating, helping POS terminals meet Energy Star standby requirements. The industrial temperature range ensures reliability in retail environments with fluctuating thermal conditions. Limitation: the half-duplex mode requires careful DE/RE timing for full-duplex peripherals.
Recommended
Multi-Drop Sensor Networks
Multi-drop sensor networks benefit from the ISL83485IBZ-T's 1/8 unit-load receiver, which permits up to 256 sensor nodes on a single twisted-pair RS-485 bus. Each sensor MCU drives the DI line of its transceiver and reads back on RO, achieving half-duplex polling at 10Mbps for time-critical measurements. The 3.3V rail matches low-power MCU families, and the BiCMOS drive strength handles the cable capacitance of large sensor installations. The 8-SOIC footprint is small enough for compact sensor PCBAs, and the shutdown pin lets battery-powered sensors idle at microamp current between measurements. Compared to CAN-bus alternatives, RS-485 with ISL83485IBZ-T offers higher node count and longer cable reach.
Recommended
Recommended Products Summary
Engineering reference data for ISL83485IBZ-T — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ISL83485IBZ | MAX3485ESA | ADM3485EARZ | ST3485EIDT |
|---|---|---|---|---|---|
| Brand | Renesas Electronics | Renesas Electronics | Maxim Integrated | Analog Devices | STMicroelectronics |
| Package | 8-SOIC (IB) | 8-SOIC (IB) - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same |
| Supply Voltage | 3.3 V (3.0-3.6 V) | 3.3 V (3.0-3.6 V) | 3.3 V (3.0-3.6 V) | 3.3 V (3.0-3.6 V) | 3.3 V (3.0-3.6 V) |
| Data Rate | 10 Mbps | 10 Mbps | 10 Mbps | 10 Mbps | 10 Mbps |
| Duplex | Half | Half | Half | Half | Half |
| Receiver Input Impedance | 1/8 unit-load (256 nodes) | 1/8 unit-load | 1/8 unit-load | 1/8 unit-load | 1/8 unit-load |
| Shutdown Pin | Yes | Yes | No | Yes | Yes |
| Lifecycle Status | Last Time Buy (Renesas, 2026-10-16) | Last Time Buy | Active | Active | Active |
Key Differentiators
- Last Time Buy from Renesas vs active cross-brand alternatives (vs MAX3485ESA)
- Shutdown pin reduces standby current to microamp level (vs MAX3485ESA)
- 1/8 unit-load supports denser RS-485 networks (vs Legacy MAX485 (1 unit-load))
- Industry-standard 8-SOIC pinout matches MAX485/SN75176B (vs MAX3485ESA)
Design Notes
Place a 100nF ceramic decoupling capacitor within 5 mm of the VCC pin (pin 8) and a 10uF bulk capacitor on the 3.3V rail to suppress transients during hot-plug events. The 8-SOIC thermal pad is not present, so no bottom-side copper plane is required, but keep ground return paths short to maintain signal integrity on the differential A/B pins.
Route the differential A and B signals as a 100 ohm differential pair with controlled impedance, keeping traces short and matched within 5 mm length difference. Add a 120 ohm differential termination at each cable end to prevent reflections on long RS-485 runs. Maintain at least 3x the trace width of spacing from the bus traces to reduce crosstalk.
Tie the RE pin (pin 2) high through a 100k pull-up to VCC when unused, to avoid floating logic that can cause the receiver output RO to oscillate and draw excess current. Tie the DE pin (pin 3) low through a 100k pull-down to disable the driver when unused, preventing unwanted bus contention. Do not float either enable pin - the ISL83485IBZ-T does not have internal pull-ups on these pins.
The ISL83485IBZ-T supports up to 256 nodes on a single bus thanks to its 1/8 unit-load receiver, but practical bus length depends on data rate. At 10Mbps, keep cable runs below 30 m to avoid edge-rate degradation. For longer runs, drop to 1Mbps or use the ISL83483 (slew-rate-limited variant) to improve EMI and signal integrity.
Estimated: at 3.3V VCC, 10Mbps operation, and typical RS-485 loading, the ISL83485IBZ-T dissipates under 100 mW. The 8-SOIC package has adequate thermal resistance (~150 C/W) for normal industrial operation without a heatsink. Avoid placing the part near high-power switching devices to minimize thermal coupling.
Compliance Information
ROHS3 compliant per distributor data. Not AEC-Q100 qualified (industrial grade only). Lead-free per -Z suffix. REACH and conflict minerals status not specified in provided data.
