Part A
ADM4850ARZ
ADI公司
- Lifecycle
- Active
- Stock
- 7538 件
- Package
- SOP-8
- Series
- 介面-驅動器、接收器、收發器
Replacement verdict
Compatible functional replacement candidate
The ADM4850ARZ and ADM4855AR are both half-duplex RS-485/RS-422 transceivers in an 8-lead SOIC package with a 5 V supply and 1/8 unit load, making them functionally interchangeable for most bus-node applications. The ADM4855AR adds enhanced ESD protection and a higher driver output, so designers should confirm ESD robustness and drive-level requirements before substituting the ADM4850ARZ in place of the ADM4855AR.
Interface Protocol
High match
Package Type
High match
Supply Voltage
High match
ESD Protection
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 | ADM4855AR | Why it matters |
|---|---|---|---|
| Data Rate | 250 kbps | 500 kbps | Maximum signaling speed; the faster device supports higher throughput but may require more careful cabling and termination. |
| Duplex Mode | Half-duplex | Full-duplex | Determines whether simultaneous transmit and receive is possible; full-duplex needs four wires versus two for half-duplex. |
| Number of Drivers/Receivers | 1 driver / 1 receiver | 1 driver / 1 receiver | Defines the transceiver channel count; both are single-channel devices suitable for point-to-point links. |
| Supply Voltage | 5 V | 5 V | Operating rail voltage; both require a 5 V supply, so power design is compatible. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Ambient range over which the device is specified; identical industrial ranges allow use in the same environments. |
| Mounting Type | Surface mount | Surface mount | PCB assembly method; both are surface-mount SOIC packages, so board footprint style is consistent. |
| Package / Case | 8-SOIC | 8-SOIC | Physical package outline; matching 8-SOIC packages allow drop-in footprint compatibility. |
| Number of Pins | 8 | 8 | Pin count affects layout and socketing; both have 8 pins, simplifying substitution. |
| Protocol | RS-485 | RS-485 | Communication standard supported; both target RS-485 networks, ensuring protocol-level compatibility. |
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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 | ADM4855AR |
|---|---|---|
| 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 ADM4855AR?
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, while the ADM4855AR is a higher-speed half-duplex RS-485/RS-422 transceiver rated for data rates up to 20 Mbps. Both are 5 V single-supply devices in 8-lead SOIC packages, but they differ in maximum data rate, driver output slew characteristics, and intended bus speed.
Are the ADM4850ARZ and ADM4855AR pin-compatible?
Yes. Both devices are offered in the same 8-lead SOIC (R-8) package with the same pinout: RO, RE, DE, DI, GND, A, B, and VCC. This allows them to share a common PCB footprint, though the higher data rate of the ADM4855AR may require review of bus termination and layout for signal integrity.
What supply voltage do the ADM4850ARZ and ADM4855AR require?
Both devices operate from a single 5 V supply (VCC = 5 V ±5%). They are not 3.3 V parts, so designs requiring 3.3 V operation should use a different transceiver family.
What is the maximum data rate of each device?
The ADM4850ARZ supports data rates up to 115.2 kbps with slew-rate-limited driver outputs, which helps reduce EMI and reflections on long or unterminated buses. The ADM4855AR supports data rates up to 20 Mbps for higher-speed RS-485/RS-422 communication.
Do both parts support half-duplex operation?
Yes. Both the ADM4850ARZ and ADM4855AR are half-duplex transceivers, sharing the A and B bus pins for both transmit and receive, with separate RE and DE enable pins for receiver and driver control.
How many bus nodes can each transceiver support?
Both devices are designed for standard RS-485/RS-422 multidrop buses and provide a 1/4 unit load receiver input impedance, allowing up to 256 nodes on a single bus, consistent with the Analog Devices ADM4850/ADM4855 datasheet specifications.
Which part should be selected for a long, low-EMI bus versus a high-speed bus?
For long buses or applications sensitive to EMI and reflections, the ADM4850ARZ with its slew-rate-limited 115.2 kbps driver is generally preferred. For high-throughput links such as industrial backplanes or fast point-to-point RS-422 connections, the ADM4855AR with its 20 Mbps capability is the appropriate choice, provided the bus is properly terminated and laid out.
Are the ADM4850ARZ and ADM4855AR specified over the same temperature range?
Both devices are specified for the industrial temperature range of −40°C to +85°C, as stated in the Analog Devices ADM4850/ADM4855 datasheet, making them suitable for industrial networking and control applications.