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 AM26C31CDRG4 are functionally equivalent quad differential line drivers from the same AM26C31 family, sharing identical logic function, channel count, supply voltage range, and SOIC-16 package footprint. Both are suitable for RS-422/RS-485 differential transmission applications, with the primary distinction being the manufacturer-specific suffix and qualification grade rather than core electrical performance.
Logic Function
High match
Channel Count
High match
Package Type
High match
Supply Voltage Range
Validation required
Parts at a glance
Part B
AM26C31CDRG4
德州儀器
- Lifecycle
- Active
- Stock
- 7066 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 | AM26C31CDRG4 | 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 match the signaling requirements of the target interface. |
| Package / Mounting | SOIC-16, surface mount | SOIC-16, surface mount | Identical 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 matters for automotive or industrial environments requiring extended thermal tolerance. |
| Qualification / Grade | Automotive qualified (Q-grade) | Commercial grade | Automotive qualification affects reliability screening and suitability for automotive or harsh-environment designs. |
| Product Status / Lifecycle | Active | Not recommended for new designs (NRND) | Lifecycle status affects long-term availability and whether the part should be designed into new products. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AM26C31QDR | AM26C31CDRG4 |
|---|---|---|
| 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 AM26C31CDRG4 devices?
Both are Texas Instruments AM26C31 series quad differential line drivers implementing the RS-422/RS-485 physical layer. They contain four 3-state differential line drivers with active-high enable inputs and are intended for balanced transmission over twisted-pair or parallel-wire cables. The AM26C31QDR is supplied in a 16-pin SOIC package (D suffix) on a large tape-and-reel (R suffix), while the AM26C31CDRG4 is the same 16-pin SOIC tape-and-reel device with a G4 lead-finish/Green-material designation.
Are the AM26C31QDR and AM26C31CDRG4 functionally interchangeable?
Yes. Both devices share the same AM26C31 core: four differential drivers, TTL-compatible inputs, 3-state outputs, and the same 16-pin SOIC pinout. The QDR and CDRG4 suffixes denote ordering/package-finish variants rather than different electrical functions, so they are functionally equivalent when the package and environmental grade meet the application requirements.
What is the difference between the QDR and CDRG4 suffixes?
The "Q" in AM26C31QDR denotes the automotive Q100 qualified grade, while the "C" in AM26C31CDRG4 denotes the commercial/industrial grade. Both are 16-pin SOIC tape-and-reel (R) devices; the G4 suffix on the CDRG4 indicates Green (RoHS-compliant, lead-free) material. The primary selection difference is the qualification grade and associated temperature range, not the driver function.
What are the operating temperature ranges for these two variants?
The AM26C31QDR (Q100 automotive grade) is specified over the -40°C to +125°C ambient temperature range. The AM26C31CDRG4 (commercial grade) is specified over 0°C to +70°C. Designs exposed to ambient temperatures outside 0°C to +70°C should use the Q-grade device or another variant rated for the required range.
What supply voltage and output characteristics do these drivers support?
Both devices operate from a single 5 V supply (nominally 4.5 V to 5.5 V). Each driver provides differential outputs meeting RS-422/RS-485 requirements, with output differential voltage typically around 2 V into a 100 Ω load and short-circuit current limited by the internal protection circuitry. Inputs are TTL-compatible, and the 3-state enable pins allow the outputs to be placed in a high-impedance state for bus sharing.
Can the AM26C31QDR and AM26C31CDRG4 be used as drop-in replacements for each other on an existing PCB?
Yes, from a footprint perspective. Both are 16-pin SOIC (D) packages with identical pin assignments, so the PCB land pattern is the same. However, the substitution must be validated against the target design's temperature range and qualification requirements: replacing a Q-grade device with a C-grade device may violate the application's environmental or automotive qualification requirements even though the footprint and function match.
Are these devices RoHS compliant and what lead finish do they use?
The AM26C31CDRG4 carries the G4 suffix, which denotes Green/RoHS-compliant material with a lead-free (NiPdAu) lead finish. The AM26C31QDR is also offered in RoHS-compliant, lead-free construction as part of TI's standard Q100 portfolio. Designers should confirm the specific lead finish and RoHS status on the manufacturer's datasheet for the exact orderable part number before finalizing compliance documentation.
What data rate and bus topology are these drivers suitable for?
The AM26C31 family is specified for balanced differential data transmission at signaling rates up to approximately 10 Mbps, depending on cable length and loading. They are suited to point-to-point and multidrop RS-422/RS-485 buses, with the 3-state enable allowing multiple drivers to share a bus. Actual achievable rate depends on cable characteristics, termination, and the receiver used in the system.