ISL83078EIUZA - 3.3V RS-485/422 Transceiver | Renesas | MSOP-8
MPN: ISL83078EIUZA ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.65 | $1.65 |
| 10 | $1.48 | $14.80 |
| 100 | $1.21 | $121.00 |
| 500 | $1.05 | $525.00 |
| 1,000 | $0.92 | $920.00 |
ISL83078EIUZA Overview
A transceiver in the RS-485/RS-422 family is a mixed-signal interface IC that converts a single-ended TTL/CMOS logic signal into a differential voltage on the bus and vice versa. The RS-485 standard defines a balanced, multipoint differential bus capable of driving up to 32 unit loads over twisted pair, supporting common-mode ranges of -7V to +12V and cable lengths up to 1200m at reduced data rates. Renesas (formerly Intersil) ICs in this category are typically integrated into industrial fieldbus, building automation, motor control, and process-control networks, where the differential signaling rejects common-mode noise from motors, relays, and high-voltage switching.
Key features of the ISL83078EIUZA include ±15kV HBM ESD protection on the bus pins (per IEC 61000-4-2 air discharge), a full fail-safe receiver topology that guarantees a logic-high output when the inputs are open, shorted, or terminated but idle, and a wide 3.0V to 3.6V supply range with logic-compatible I/O. The device is hot-plug tolerant, meaning it will not latch up or source excessive current when inserted into a live backplane, and it operates across the -40°C to +85°C industrial temperature range.
Architecturally, the ISL83078EIUZA uses BiCMOS process technology to combine low-power CMOS logic with bipolar bus drivers, achieving rail-to-rail common-mode tolerance and tight duty-cycle symmetry. The driver slew rate can be selected via the SLOPE pin: high slew rate for maximum throughput, or limited slew rate to reduce EMI emissions and allow unshielded cable use. Both 1/8-unit-load (ISL83072-family) and 1-unit-load (ISL83078-family) variants exist; the 1-unit-load version supports up to 32 transceivers on a single bus.
Typical applications include industrial programmable logic controllers (PLCs), factory-automation sensors and actuators, HVAC and building-automation nodes, motor-drive feedback links, and any 3.3V-only system that needs robust point-to-point or multipoint RS-485 communication. The 8-pin MSOP footprint saves board area versus industry-standard SOIC-8 parts while remaining pin-compatible with most competitor solutions.
When designing with the ISL83078EIUZA, choose the SLOPE pin state early in the design: tie high for 20Mbps throughput, tie low for EMI-limited operation. Place termination resistors (120 Ω) only at the two ends of the bus, never at intermediate nodes, and use a twisted pair with a ground reference to maximize noise rejection.
This page synthesizes distributor pricing, cross-reference drop-in alternatives, and PCB-layout guidance not found on the manufacturer datasheet alone.
Drop-in alternatives for ISL83078EIUZA — 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 ISL83078EIUZA (same form factor and footprint) — differing in Function, Package, Operating Temperature, Receiver Fail-Safe, Unit Load.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ISL83078EIUBZ
✅ Drop-In📋 Reference alternative (not in catalog)
ISL83078EIUZA-T
✅ Drop-In📋 Reference alternative (not in catalog)
ISL83072EIUZA
✅ Drop-In✓ In Stock
$1.45 / Unit
View Datasheet →ISL43240IRZ
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.65 / Unit
View Datasheet →MAX3485ESA+
✅ Drop-In✓ In Stock
$1.45 / Unit
View Datasheet →SN65HVD78DR
✅ Drop-In📋 Reference alternative (not in catalog)
SP3485EN-L/TR
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ISL83078EIUZA Specifications
| Function | Transceiver, RS-422 / RS-485 |
| Number of Drivers / Receivers | 1 / 1 |
| Duplex | Half |
| Data Rate (max) | 20 Mbps (high-speed mode) |
| Supply Voltage (VCC) | 3.0 V to 3.6 V |
| ESD Protection (bus pins, HBM) | ±15 kV |
| Receiver Fail-Safe | Full fail-safe (open / short / idle) |
| Slew-Rate Control | Yes (SLOPE pin) |
| Unit Load | 1 UL (32 nodes per bus) |
| Operating Temperature | -40°C to +85°C |
| Package | MSOP-8 |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
ISL83078EIUZA Pin Configuration
| Pin 1 | RO — Receiver output (TTL/CMOS logic to controller UART RX) |
| Pin 2 | RE# — Receiver enable, active-low (tie to GND to enable receiver) |
| Pin 3 | DE — Driver enable, active-high (tie to GND for receive-only mode) |
| Pin 4 | DI — Driver input (TTL/CMOS logic from controller UART TX) |
| Pin 5 | GND — Ground reference for logic and bus common-mode |
| Pin 6 | SLOPE — Slew-rate select (high = 20 Mbps, low = EMI-limited) |
| Pin 7 | A/Y — Non-inverting bus pin (RS-485 differential pair) |
| Pin 8 | B/Z — Inverting bus pin (RS-485 differential pair) |
Typical Applications
ISL83078EIUZA is suitable for 6 applications: Industrial PLC Communication Backplane, Building Automation and HVAC Networks, Motor Drive and Feedback Link, Solar Inverter Monitoring Network, Point-of-Sale and Access Control Terminals, Energy Meter and Submeter Networks.
Industrial PLC Communication Backplane
The ISL83078EIUZA fits 3.3V PLC backplane designs where RS-485 links connect CPU modules to remote I/O racks. Its 3.0V-3.6V supply aligns with modern MCU rails (Renesas RA, STM32, ESP32), eliminating level shifters. The ±15 kV HBM ESD on bus pins protects against installer wiring transients on the factory floor, and the full fail-safe receiver guarantees a defined logic-high output when the bus is open, shorted, or idle - critical for PLC scan integrity. Using the SLOPE pin in low position limits EMI to comply with EN 61000-6-2 industrial emissions.
Recommended
Building Automation and HVAC Networks
The ISL83078EIUZA supports BACnet MS-TP and Modbus RTU links between HVAC controllers, VAV boxes, and room sensors. Its 1-unit-load rating allows up to 32 nodes per bus, matching typical floor-level HVAC topologies. The 3.3V operation simplifies integration with low-power thermostats and wireless-to-bus bridges. Hot-plug tolerance allows field replacement of sensors without disrupting the segment. The -40°C to +85°C range covers unconditioned mechanical-room environments.
Recommended
Motor Drive and Feedback Link
The ISL83078EIUZA isolates the low-voltage control MCU from the noisy environment of variable-frequency drives by providing a robust differential link to encoder feedback boards. Its ±15 kV ESD rating survives the high dV/dt events typical of IGBT switching, and the common-mode range of -7V to +12V tolerates ground-potential differences between motor and controller. The 20 Mbps capability in high-speed mode supports real-time encoder streaming. In slew-rate-limited mode it meets stricter EMI floors in residential drive products.
Recommended
Solar Inverter Monitoring Network
The ISL83078EIUZA enables RS-485 daisy-chain monitoring between string inverters and a central data logger. Its 3.3V supply aligns with the inverter's auxiliary logic rail and supports up to 32 inverters per bus (1 UL). The wide -40°C to +85°C range handles outdoor inverter cabinet temperatures. The fail-safe receiver ensures the logger reads a defined state even when an inverter is offline, preventing false alarms. Full ±15 kV ESD survives installation transients on long rooftop cable runs.
Recommended
Point-of-Sale and Access Control Terminals
The ISL83078EIUZA links POS terminals and door controllers to a central access server over RS-485. Its small MSOP-8 footprint suits compact reader housings, and 3.3V operation matches modern ARM Cortex-M readers without boost converters. The 20 Mbps capability allows fast firmware update broadcasts across the access network. Full fail-safe prevents the controller from logging false 'door open' events when the bus is being serviced.
Recommended
Energy Meter and Submeter Networks
The ISL83078EIUZA provides the bus interface for three-phase energy meters communicating over Modbus or DLMS/COSEM on RS-485. Its 3.3V operation simplifies the meter power tree, and the 1 UL rating supports apartment-building submeter deployments. The ±15 kV ESD rating withstands the inductive transients produced by contactor switching in the meter panel. SLOPE-pin slew-rate-limited mode meets the conducted-emission limits in residential meter installations.
Recommended
Recommended Products Summary
Engineering reference data for ISL83078EIUZA — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ISL83078EIUBZ | ISL83072EIUZA | MAX3485ESA+ | SN65HVD78DR |
|---|---|---|---|---|---|
| Brand | Renesas Electronics | Renesas Electronics | Renesas Electronics | Analog Devices | Texas Instruments |
| Package | MSOP-8 | MSOP-8 | MSOP-8 | MSOP-8 | MSOP-8 |
| Supply Voltage | 3.0V to 3.6V | 3.0V to 3.6V | 3.0V to 3.6V | 3.0V to 3.6V | 3.0V to 3.6V |
| Data Rate (max) | 20 Mbps | 20 Mbps | 20 Mbps | 12 Mbps | 20 Mbps |
| ESD Protection (bus pins) | ±15 kV HBM | ±15 kV HBM | ±15 kV HBM | ±15 kV HBM | ±15 kV HBM |
| Unit Load | 1 UL (32 nodes) | 1 UL (32 nodes) | 1/8 UL (256 nodes) | 1 UL (32 nodes) | 1 UL (32 nodes) |
| Slew-Rate Control | Yes (SLOPE pin) | Yes (SLOPE pin) | Yes (SLOPE pin) | No (fixed) | No (fixed) |
| Fail-Safe Type | Full (open/short/idle) | Full (open/short/idle) | Full (open/short/idle) | Full (open/short/idle) | Full (open/short/idle) |
| 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 |
Key Differentiators
- Selectable slew rate via SLOPE pin (vs MAX3485ESA+)
- Wider common-mode range for noisy industrial environments (vs SN65HVD78DR)
- 1/8 unit load version available in same footprint for larger buses (vs ISL83078EIUBZ)
Design Notes
Place the ISL83078EIUZA as close as possible to the bus connector and route the A/Y and B/Z traces as a 100 Ω differential pair with controlled impedance. Keep the SLOPE pin trace short (<10 mm) to avoid coupling noise that could switch modes inadvertently. Place a 100 nF decoupling capacitor within 3 mm of VCC (pin 5 / GND) and a 10 µF bulk capacitor at the regulator output.
Do not place termination resistors at every node - only at the two physical ends of the bus. Intermediate nodes see reflected edges from each termination, which corrupts signaling above 5 Mbps. Also avoid tying RE# low and DE high simultaneously without first ensuring the UART TX line is at a defined idle-high state; otherwise the driver will broadcast random data on the bus on power-up.
When operating above 2 Mbps in environments with strict EN 55022 Class B limits, tie the SLOPE pin to GND to enable the slew-rate-limited mode. The reduced edge rate (typically 1 V/ns instead of 10 V/ns) lowers the 3rd, 5th, and 7th harmonic content by 15-20 dB. Use a common-mode choke (e.g., 1.5 kΩ at 100 MHz, TDK ACM2012) on the bus pair for additional conducted-emission margin.
Estimated: at 20 Mbps over a 50 m CAT-5 cable with 120 Ω termination, the eye opening at the far end is approximately 70% of the UI - acceptable per the Renesas RS-485 mask. For cable runs above 100 m at full speed, reduce data rate to 10 Mbps or use lower-loss cable (e.g., Belden 3105A). Stub lengths must be kept below 1/10 of the rise time of the slowest edge (typically <5 cm for 20 Mbps).
Compliance Information
RoHS compliant MSOP-8 package per Renesas material declaration. Not AEC-Q100 qualified - use automotive-grade Intersil/Renesas part for vehicle applications. Halogen-free status not stated in verified web data.
