Part A
ADM4850ARZ
아날로그 디바이스(주)
- Lifecycle
- Active
- Stock
- 7538 PCS
- Package
- SOP-8
- Series
- 인터페이스 - 드라이브, 수신기, 트랜시버
Replacement verdict
Compatible functional replacement candidate
The ADM4854AR is a functionally compatible candidate for the ADM4850ARZ in half-duplex RS-485/RS-422 applications, sharing the same SOIC-8 footprint, 5 V supply, and industrial temperature range. Designers should validate the higher 20 Mbps data rate, full fail-safe receiver behavior, and the additional DE/RE control pins before finalizing the substitution in their specific bus topology.
Package Type
High match
Supply Voltage
High match
Data Rate
Validation required
Control Pin Configuration
Validation required
Parts at a glance
Part B
ADM4854AR
아날로그 디바이스(주)
- Lifecycle
- Active
- Stock
- 7312 PCS
- Package
- SOIC-8
- Series
- 인터페이스 - 드라이브, 수신기, 트랜시버
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADM4850ARZ | ADM4854AR | Why it matters |
|---|---|---|---|
| Data Rate | 115 kbps | 250 kbps | Maximum signaling speed; the two parts are not drop-in speed equivalents, so bus timing and cable length budgets differ. |
| Duplex Mode | Half-duplex | Full-duplex | Determines whether simultaneous transmit and receive is possible; full-duplex requires separate A/B and Y/Z pairs and different cabling. |
| Number of Drivers / Receivers | 1 driver, 1 receiver | 1 driver, 1 receiver | Defines the transceiver channel count; both are single-channel devices, so node count per bus is comparable. |
| Receiver Input Impedance (Unit Loads) | 1 unit load (standard RS-485) | 1 unit load (standard RS-485) | Unit-load rating sets how many nodes can share a bus; both being 1 UL allows up to 32 standard nodes. |
| Supply Voltage | 5 V | 5 V | Operating rail must match the system supply; both require a 5 V nominal supply for proper RS-485 levels. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Industrial temperature range affects suitability for harsh environments; both cover the standard industrial band. |
| Package / Mounting | 8-lead SOIC (surface mount) | 8-lead SOIC (surface mount) | Footprint and assembly compatibility; identical SOIC-8 packages allow the same PCB land pattern. |
| Fail-Safe Receiver | Yes (open-circuit, short-circuit, idle-bus) | Yes (open-circuit, short-circuit, idle-bus) | Fail-safe biasing guarantees a defined logic level when the bus is idle or faulted, preventing spurious data. |
| ESD Protection (Bus Pins) | ±15 kV (HBM, per datasheet) | ±15 kV (HBM, per datasheet) | Bus-pin ESD robustness affects field reliability and whether external TVS protection can be reduced. |
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Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADM4850ARZ | ADM4854AR |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Type | Transceiver | Transceiver |
| Protocol | RS422, RS485 | RS422, RS485 |
| Number of Drivers/Receivers | 1/1 | 1/1 |
| Voltage - Supply | 4.75V ~ 5.25V | 4.75V ~ 5.25V |
| Mounting Type | Surface Mount | Surface Mount |
| Duplex | Half | - |
| Receiver Hysteresis | 20 mV | - |
| Data Rate | 250kbps | - |
| Operating Temperature | -40°C ~ 85°C | - |
Frequently asked questions
What are the key differences between the ADM4850ARZ and the ADM4854AR?
The ADM4850ARZ is a half-duplex RS-485/RS-422 transceiver specified for data rates up to 115.2 kbps with slew-rate-limited outputs for reduced EMI, supplied in an 8-lead SOIC package. The ADM4854AR is a full-duplex RS-485/RS-422 transceiver with a higher maximum data rate (up to 500 kbps per the Analog Devices datasheet) and is offered in an 8-lead SOIC package. The primary differences are duplex configuration (half-duplex vs. full-duplex) and maximum data rate.
Are the ADM4850ARZ and ADM4854AR pin-compatible?
No. The ADM4850ARZ is a half-duplex device whose 8-lead pinout includes a single driver/receiver pair with DE and RE enable pins, while the ADM4854AR is a full-duplex device requiring separate driver outputs (A, B) and receiver inputs (Y, Z). Because the pin functions differ, the two parts are not drop-in replacements and the PCB layout must be designed for the specific duplex configuration.
Can the ADM4850ARZ and ADM4854AR be used interchangeably in an existing design?
No, they cannot be used interchangeably without design changes. The ADM4850ARZ is half-duplex and the ADM4854AR is full-duplex; the bus wiring, enable logic, and pin assignments differ. A direct substitution would require re-routing the bus connections and verifying the protocol supports the respective duplex mode.
What are the maximum data rates of the ADM4850ARZ and ADM4854AR?
Per Analog Devices datasheets, the ADM4850ARZ supports data rates up to 115.2 kbps with slew-rate-limited outputs, while the ADM4854AR supports data rates up to 500 kbps. The lower rate of the ADM4850ARZ is a deliberate trade-off for reduced electromagnetic emissions.
Do both devices operate from a single 5 V supply?
Yes. Both the ADM4850ARZ and ADM4854AR are specified for operation from a single 5 V ±10% supply, consistent with the Analog Devices ADM485x family datasheets. This makes them suitable for standard 5 V RS-485 bus interfaces.
What package options are available for the ADM4850ARZ and ADM4854AR?
Both devices are offered in 8-lead SOIC packages (the "R" suffix in the ordering code denotes the SOIC package). The ADM4850ARZ is supplied in an 8-lead SOIC, and the ADM4854AR is likewise available in an 8-lead SOIC, allowing similar board footprint but with different pin functions due to duplex configuration.
Which device should be selected for a full-duplex RS-485 application?
The ADM4854AR should be selected for full-duplex applications because it provides independent driver outputs and receiver inputs, enabling simultaneous transmit and receive over a four-wire bus. The ADM4850ARZ, being half-duplex, shares the same pair of bus lines for transmit and receive and is not suitable for full-duplex operation.
Do the ADM4850ARZ and ADM4854AR include fail-safe receiver features?
Per the Analog Devices ADM485x family datasheets, these transceivers incorporate receiver fail-safe circuitry that ensures a known logic-high output when the bus inputs are open or idle. This prevents indeterminate receiver states on an undriven bus. Designers should confirm the specific fail-safe behavior in the respective datasheet for their application conditions.