Part A
ADM4850ARZ
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 ADM488AR are both half-duplex RS-485/RS-422 transceivers in 8-lead SOIC packages with 5 V supply operation, making them functionally interchangeable for many designs. However, the ADM488AR offers a higher maximum data rate and a wider operating temperature range, while the ADM4850ARZ provides lower quiescent supply current. Verify data rate, node count, and thermal margin against the target application before substituting.
Package Type
High match
Supply Voltage
High match
Data Rate
Validation required
Operating Temperature 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 | ADM488AR | Why it matters |
|---|---|---|---|
| Data Rate | 250 kbps | 250 kbps | Maximum signaling speed; both support the same rate, so timing compatibility is preserved. |
| Duplex Mode | Half-duplex | Full-duplex | Determines whether simultaneous transmit and receive is possible; full-duplex requires separate A/B and Y/Z pairs, affecting bus wiring. |
| Number of Drivers/Receivers | 1 driver / 1 receiver | 1 driver / 1 receiver | Defines the transceiver channel count; identical here, so node count per bus is comparable. |
| Supply Voltage | 5 V | 5 V | Operating supply must match the system rail; both are 5 V devices, so power design is interchangeable. |
| Supply Current | Typically 300 µA (unloaded) | Typically 500 µA (unloaded) | Quiescent current affects power budget; the ADM488AR draws somewhat more, which may matter in low-power designs. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Defines environmental limits; identical industrial range supports the same application environments. |
| Package / Mounting | 8-lead SOIC (surface mount) | 8-lead SOIC (surface mount) | Footprint and assembly compatibility; matching package allows drop-in board replacement. |
| Receiver Input Impedance (Unit Loads) | 1 unit load (standard RS-485) | 1 unit load (standard RS-485) | Determines maximum nodes on a bus; both being 1 unit load allows up to 32 standard nodes. |
| Fail-Safe Receiver | Yes (open-circuit fail-safe) | Yes (open-circuit fail-safe) | Ensures a defined logic state when the bus is idle or disconnected, preventing spurious data. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADM4850ARZ | ADM488AR |
|---|---|---|
| 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 ADM488AR?
The ADM4850ARZ is a half-duplex RS-485/RS-422 transceiver specified for data rates up to 20 Mbps, while the ADM488AR is a half-duplex RS-485/RS-422 transceiver rated for data rates up to 250 kbps. Both are 8-lead SOIC devices from Analog Devices, but they differ in maximum data rate, slew-rate limiting, and quiescent supply current.
Are the ADM4850ARZ and ADM488AR pin-compatible?
Yes. Both devices are offered in an 8-lead SOIC package with the same pinout (RO, RE, DE, DI, GND, A, B, VCC), so they are pin-compatible and can share the same PCB land pattern.
What supply voltage do the ADM4850ARZ and ADM488AR require?
Both devices operate from a single 5 V supply (4.75 V to 5.25 V typical operating range) and are specified for the industrial temperature range of −40 °C to +85 °C.
How do the data rates of the ADM4850ARZ and ADM488AR compare?
The ADM4850ARZ supports data rates up to 20 Mbps, making it suitable for high-speed RS-485 links. The ADM488AR is limited to 250 kbps and features slew-rate-limited outputs that reduce EMI and reflections, making it better suited to lower-speed, longer-cable applications.
Can the ADM488AR be used as a drop-in replacement for the ADM4850ARZ?
Because they are pin-compatible and share the same 5 V supply and 8-lead SOIC package, the ADM488AR can physically replace the ADM4850ARZ. However, the replacement is only valid if the system's data rate does not exceed 250 kbps, since the ADM488AR is slew-rate limited and cannot support the 20 Mbps rate of the ADM4850ARZ.
Do both devices support half-duplex RS-485 and RS-422 operation?
Yes. Both the ADM4850ARZ and ADM488AR are half-duplex transceivers compliant with RS-485 and RS-422 standards, featuring a differential driver and receiver with enable controls (DE and RE) for bus sharing.
How do the quiescent supply currents of the ADM4850ARZ and ADM488AR differ?
The ADM488AR is specified with a low quiescent supply current suitable for power-sensitive designs, while the ADM4850ARZ, optimized for higher speed, draws a higher quiescent current. Designers should consult the respective Analog Devices datasheets for the exact specified values before finalizing power budgets.