Part A
AM26C31QDR
德州儀器
- Lifecycle
- Active
- Stock
- 1424 件
- Package
- SOIC-16
- Series
- 介面-驅動器、接收器、收發器
Replacement verdict
Compatible functional replacement candidate
The AM26C31QDR and AM26C31CDG4 are functionally equivalent quad differential line drivers sharing the same RS-422/RS-485 interface architecture, supply voltage range, and logic family, making them viable substitutes in most designs. The primary distinction lies in package and qualification grade, so the AM26C31QDR (SOIC-16, automotive Q100 qualified) can replace the AM26C31CDG4 (SOIC-16, commercial grade) where the tighter automotive qualification is acceptable, while footprint and electrical behavior remain compatible.
Function and Logic Family
High match
Supply Voltage Range
High match
Package Type
High match
Qualification Grade
Validation required
Parts at a glance
Part B
AM26C31CDG4
德州儀器
- Lifecycle
- Active
- Stock
- 6972 件
- Package
- SOIC-16
- Series
- 介面-驅動器、接收器、收發器
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AM26C31QDR | AM26C31CDG4 | Why it matters |
|---|---|---|---|
| Function | Quadruple differential line driver | Quadruple differential line driver | Both devices perform the same core function, so they are functionally interchangeable in RS-422/RS-485 driver applications. |
| Number of Drivers | 4 | 4 | Matching driver count ensures the same number of differential channels are available for the bus interface. |
| Supply Voltage (Typical) | 5 V | 5 V | Both operate from the same nominal 5 V supply, so the power rail design does not need to change. |
| Output Type | Differential (3-state) | Differential (3-state) | Three-state differential outputs allow bus sharing and are essential for multipoint bus topologies. |
| Data Rate | Up to 10 Mbps | Up to 10 Mbps | Identical maximum data rate means both support the same signaling bandwidth requirements. |
| Package / Mounting | SOIC-16, surface mount | SOIC-16, surface mount | Same package and mounting style allow drop-in PCB replacement without layout changes. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +85 °C | The wider temperature range of the QDR variant suits harsher environments, while the CDG4 is limited to standard commercial/industrial conditions. |
| Product Grade / Qualification | Automotive Q-grade (AEC-Q100) | Commercial/industrial grade | The Q-grade part is qualified for automotive use, which affects reliability requirements and suitability for automotive designs. |
| RoHS Compliance | RoHS compliant | RoHS compliant (G4 suffix) | Both meet RoHS requirements, so environmental compliance is maintained regardless of which part is used. |
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 | AM26C31QDR | AM26C31CDG4 |
|---|---|---|
| Supplier | - | Texas Instruments |
| Part Status | Active | Discontinued at Digi-Key |
| Type | - | Driver |
| Number of Drivers/Receivers | - | 4/0 |
| Voltage - Supply | - | 4.5V ~ 5.5V |
| Operating Temperature | - | 0°C ~ 70°C |
| Mounting Type | - | Surface Mount |
Frequently asked questions
What are the AM26C31QDR and AM26C31CDG4 devices?
Both are Texas Instruments AM26C31 quad differential line drivers implementing the RS-422/RS-485 electrical interface. They contain four 3-state differential line drivers with active-high enable inputs and are intended for balanced multipoint bus transmission over twisted-pair cable.
What is the difference between the AM26C31QDR and AM26C31CDG4?
The AM26C31QDR is supplied in a 16-pin SOIC package (D suffix) on a large tape-and-reel (R suffix), while the AM26C31CDG4 is supplied in a 16-pin SOIC package (D suffix) in a tube/rail (G4 suffix). Both use the same AM26C31 die and share identical electrical specifications; the difference is packaging and shipping format.
Are the AM26C31QDR and AM26C31CDG4 electrically interchangeable?
Yes. Both devices are the same AM26C31 quad differential line driver in the same 16-pin SOIC body, so they are electrically and functionally interchangeable. The QDR and CDG4 suffixes denote reel versus tube packaging and do not change device performance.
What supply voltage and signaling do these devices support?
Both operate from a single 5 V supply (nominal 4.5 V to 5.5 V) and provide differential outputs compliant with RS-422 and RS-485 requirements, including a common-mode output range suitable for multipoint bus applications.
What is the pinout and package of these devices?
Both are offered in a 16-pin SOIC (D) package with the standard AM26C31 pinout: four driver inputs (1A–4A), four driver outputs (1Y–4Y and 1Z–4Z), four output-enable inputs (1G–4G), VCC, and GND. The pinout is identical between the QDR and CDG4 variants.
Can the AM26C31QDR and AM26C31CDG4 be used interchangeably in an existing design?
Yes, provided the design uses the 16-pin SOIC footprint. Because both parts share the same die, pinout, and electrical specifications, they can be substituted directly; only the packaging format (tape-and-reel versus tube) differs, which affects assembly handling rather than circuit behavior.
What are typical applications for these line drivers?
They are used for balanced differential data transmission in RS-422/RS-485 networks, industrial control and factory automation buses, motor control interfaces, and point-to-point or multipoint serial links requiring 3-state outputs for bus sharing.