Part A
ADM4850ARZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7538 PCS
- Package
- SOP-8
- Series
- Interface - Drivers, Receivers, Transceivers
Replacement verdict
Compatible functional replacement candidate
The ADM4850ARZ and ADM489AR are both half-duplex RS-485 transceivers in an 8-lead SOIC package with a 5 V supply and similar data rates, making the ADM4850ARZ a viable functional replacement candidate for the ADM489AR in many designs. However, the ADM489AR provides a full fail-safe receiver and a wider common-mode range, so the replacement should be validated against the specific fail-safe and common-mode requirements of the target application before adoption.
Package Type
High match
Supply Voltage
High match
Data Rate
Validation required
Fail-Safe and Common-Mode Range
Validation required
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 | ADM489AR | Why it matters |
|---|---|---|---|
| Data Rate | 500 kbps | 250 kbps | Maximum signaling speed; a faster device may be required for high-throughput buses, while a slower one may be chosen for noise margin. |
| Duplex Mode | Half-duplex | Full-duplex | Determines whether simultaneous transmit and receive is possible; full-duplex requires separate driver/receiver pairs and more bus wires. |
| Number of Drivers/Receivers | 1 driver / 1 receiver | 1 driver / 1 receiver | Defines the transceiver channel count; both are single-channel, so this is functionally equivalent. |
| Supply Voltage | 5 V | 5 V | Operating supply rail; both require a 5 V supply, so power design is compatible. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Industrial temperature range; identical ratings mean both suit the same environmental conditions. |
| Package / Mounting | 8-SOIC (surface mount) | 14-SOIC (surface mount) | Footprint and pin count differ; a board layout change is required when substituting between these packages. |
| Number of Pins | 8 | 14 | Pin count affects PCB footprint and routing; the 14-pin full-duplex part exposes additional pins for separate TX/RX paths. |
| Fail-Safe Receiver | Yes (open-circuit fail-safe) | Yes (open-circuit fail-safe) | Ensures a defined logic output when the bus is idle or disconnected, preventing spurious data; both provide this feature. |
| ESD Protection (Bus Pins) | ±15 kV (HBM) | ±15 kV (HBM) | Robustness against electrostatic discharge on the bus; identical ratings indicate comparable field reliability. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADM4850ARZ | ADM489AR |
|---|---|---|
| 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 | 4.5V ~ 5.5V |
| 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 primary differences between the ADM4850ARZ and the ADM489AR?
The ADM4850ARZ is a half-duplex RS-485/RS-422 transceiver specified for data rates up to 115.2 kbps, while the ADM489AR is a full-duplex RS-485/RS-422 transceiver rated for 250 kbps. The ADM4850ARZ is supplied in an 8-lead SOIC package, whereas the ADM489AR is supplied in a 14-lead SOIC package to accommodate the separate driver and receiver pins required for full-duplex operation.
Can the ADM4850ARZ and ADM489AR be used interchangeably in the same socket?
No. The ADM4850ARZ uses an 8-lead SOIC footprint with a half-duplex pinout (shared A/B bus pins), while the ADM489AR uses a 14-lead SOIC footprint with independent driver outputs (Y/Z) and receiver inputs (A/B). The package size, pin count, and pin functions differ, so they are not drop-in replacements for one another.
Do both devices support the same supply voltage and logic interface levels?
Yes. Both the ADM4850ARZ and ADM489AR operate from a single 5 V supply and provide CMOS-compatible logic inputs and outputs, allowing direct interfacing with 5 V logic without additional level shifting.
What is the difference in duplex configuration between these two transceivers?
The ADM4850ARZ is a half-duplex device, meaning its driver and receiver share the same differential bus pins, so transmission and reception cannot occur simultaneously. The ADM489AR is a full-duplex device with separate driver output pins and receiver input pins, enabling simultaneous transmit and receive operation over a four-wire bus.
How do the maximum data rates of the ADM4850ARZ and ADM489AR compare?
The ADM4850ARZ is specified for a maximum data rate of 115.2 kbps, making it suitable for low-speed, long-cable RS-485 networks. The ADM489AR is specified for a maximum data rate of 250 kbps, offering higher throughput for full-duplex applications.
Are both parts specified for the same operating temperature range?
Yes. Both the ADM4850ARZ and ADM489AR are specified over the industrial temperature range of −40°C to +85°C, making them suitable for use in industrial networking and control applications.
Which device should be selected for a four-wire full-duplex RS-485 network?
The ADM489AR should be selected for a four-wire full-duplex RS-485 network because it provides independent driver outputs and receiver inputs, allowing simultaneous bidirectional communication. The ADM4850ARZ, being half-duplex, is intended for two-wire buses where transmit and receive are time-multiplexed.