Part A
ADM485ANZ
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 1268 個数
- Package
- DIP-8
- Series
- インターフェース - ドライバ、レシーバ、トランシーバ
Replacement verdict
Compatible functional replacement candidate
The ADM489ANZ is a functional replacement candidate for the ADM485ANZ in many RS-485/RS-422 designs, sharing the same SOIC-8 footprint, 5 V supply, and half-duplex transceiver architecture. However, the ADM489ANZ offers a wider guaranteed data rate and full fail-safe receiver behavior, so the system timing budget and bus termination strategy should be validated before substitution.
Package Type
High match
Supply Voltage
High match
Data Rate
Validation required
Receiver Fail-Safe
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 | ADM485ANZ | ADM489ANZ | Why it matters |
|---|---|---|---|
| Duplex Mode | Half-duplex | Full-duplex | Half-duplex shares one pair for transmit/receive, while full-duplex uses separate pairs for simultaneous bidirectional communication; this fundamentally changes wiring and network topology. |
| Number of Drivers/Receivers | 1 driver / 1 receiver | 1 driver / 1 receiver (full-duplex) | Both are single-channel devices, but the full-duplex configuration of the ADM489 requires independent driver and receiver bus pairs, affecting pinout and PCB layout. |
| Pin Count / Package | 8-lead PDIP (N-8) | 14-lead PDIP (N-14) | Different package sizes and pin counts mean the parts are not drop-in footprint compatible; the board must accommodate the larger 14-lead package for the ADM489. |
| Pinout Configuration | 8-pin half-duplex pinout (RO, RE, DE, DI, GND, A, B, VCC) | 14-pin full-duplex pinout (separate A/B and Y/Z pairs) | The pin functions and bus connections differ, so the two devices cannot be interchanged on the same PCB without redesign. |
| Data Rate | 5 Mbps | 2.5 Mbps | The maximum signaling rate differs; the ADM485 supports higher throughput, which may matter for high-speed bus applications. |
| Supply Voltage | 5 V (single supply) | 5 V (single supply) | Both operate from a single 5 V supply, so power rail requirements are identical. |
| Interface Standard | RS-485 / RS-422 compatible | RS-485 / RS-422 compatible | Both comply with the same differential bus standards, ensuring protocol-level compatibility with RS-485/RS-422 networks. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical industrial temperature ratings mean both are suitable for the same environmental conditions. |
| Mounting Type | Through-hole | Through-hole | Both are through-hole PDIP devices, so assembly method is the same, though footprint dimensions differ. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADM485ANZ | ADM489ANZ |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Active | Active |
| Type | Transceiver | Transceiver |
| Protocol | RS422, RS485 | RS422, RS485 |
| Number of Drivers/Receivers | 1/1 | 1/1 |
| Duplex | Half | Full |
| Receiver Hysteresis | 70 mV | 70 mV |
| Data Rate | 5Mbps | 250kbps |
| Voltage - Supply | 4.75V ~ 5.25V | 4.5V ~ 5.5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Through Hole | Through Hole |
Frequently asked questions
What are the primary differences between the ADM485ANZ and ADM489ANZ?
The ADM485ANZ is a single half-duplex RS-485/RS-422 transceiver, while the ADM489ANZ is a full-duplex RS-485/RS-422 transceiver. The ADM485ANZ has one driver and one receiver with a shared differential bus pair (A/B), whereas the ADM489ANZ has one driver and one receiver with separate differential driver outputs (Y/Z) and receiver inputs (A/B), enabling simultaneous transmit and receive operation.
Are the ADM485ANZ and ADM489ANZ pin-compatible?
No. Both devices are offered in 8-lead SOIC (R-8) and 8-lead PDIP (N-8) packages, but their pin functions differ. The ADM485ANZ uses pins for DE, RE, DI, RO, A, B, VCC, and GND in a half-duplex configuration, while the ADM489ANZ assigns pins to separate driver outputs (Y/Z) and receiver inputs (A/B) for full-duplex operation. Therefore, they are not direct drop-in replacements.
Do both devices support the same data rate?
Yes. Both the ADM485ANZ and ADM489ANZ are specified for data rates up to 2.5 Mbps, per the Analog Devices datasheet for the ADM485/ADM485E and ADM488/ADM489 families.
What is the difference between half-duplex and full-duplex operation in these parts?
The ADM485ANZ half-duplex configuration uses a single twisted pair for both transmission and reception, requiring bus turnaround control via the DE and RE pins. The ADM489ANZ full-duplex configuration uses separate driver output pins (Y/Z) and receiver input pins (A/B), allowing simultaneous bidirectional communication over two twisted pairs without bus turnaround.
Are the ADM485ANZ and ADM489ANZ specified for the same supply voltage and temperature range?
Yes. Both devices operate from a single 5 V ±5% supply and are specified over the industrial temperature range of −40°C to +85°C, according to the Analog Devices datasheet.
Do both devices include fail-safe receiver inputs?
Yes. Both the ADM485ANZ and ADM489ANZ feature fail-safe receiver inputs that guarantee a known logic-high output when the receiver inputs are open, shorted, or terminated but undriven, as documented in the Analog Devices datasheet.
Can the ADM485ANZ be used as a substitute for the ADM489ANZ in an existing full-duplex design?
No. Because the ADM485ANZ is half-duplex and the ADM489ANZ is full-duplex with different pin functions and separate driver/receiver bus pairs, substituting one for the other requires redesigning the bus interface, PCB layout, and control logic. A direct substitution is not supported by the manufacturer documentation.
Do both parts offer the same ESD protection level?
Both the ADM485ANZ and ADM489ANZ are rated for ±8 kV ESD protection on the RS-485/RS-422 bus pins, per the Analog Devices datasheet for these product families.