AT80C31X2-RLTUM Microchip Integrated Circuit (Quad Flat Packages) In Stock
Microchip AT80C31X2-RLTUM is an 8-bit 8051-compatible CMOS microcontroller operating at up to 40 MHz clock frequency in a ROM-less configuration. Features expanded memory addressing via the X2 architecture and is packaged in a QFP quad flat package. Available from authorized distributors with worldwide shipping.
- Manufacturer
- Microchip
- Package
- Quad Flat Packages
- Pin Count
- 44
- Lifecycle
- ACTIVE
- Datasheet
- AT80C31X2-RLTUM Datasheet PDF
- Category
- Integrated Circuit
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- ROM-less 8051-compatible 8-bit MCU operating at up to 40 MHz for flexible external program memory configurations
- X2 architecture mode providing doubled execution speed equivalent to 80 MHz performance in standard 8051 cycle timing
- Quad Flat Package (QFP) with low-profile surface mount footprint suitable for space-constrained embedded system designs
Applications
AT80C31X2-RLTUM is used in embedded control systems, industrial automation, and legacy 8051 architecture designs where external EPROM or Flash memory stores the firmware, providing flexibility in software development and field programming. Its 40 MHz clock rate and X2 mode make it suitable for communications controllers, motor controllers, and data logging systems requiring faster 8-bit processing than standard 12 MHz 8051 cores. The ROM-less design also allows full control over code security and memory type selection.
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
Alternate & Equivalent Parts
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
What clock speed does the AT80C31X2-RLTUM support, and how does the X2 mode affect performance?
The AT80C31X2-RLTUM operates at up to 40 MHz and includes an X2 mode that doubles the instruction execution speed relative to standard 8051 timing. In X2 mode, a 40 MHz crystal effectively delivers the processing throughput of an 80 MHz standard 8051, reducing the clock cycles needed per instruction from 12 to 6, significantly improving real-time control and communication tasks in 8-bit embedded applications.
Why would a designer choose the ROM-less AT80C31X2-RLTUM instead of a flash-embedded MCU variant?
The ROM-less design of the AT80C31X2-RLTUM allows engineers to store firmware in external EPROM, NOR Flash, or OTP memory, offering maximum flexibility in prototyping and field upgrades without the cost of internal flash. It suits low-volume or frequently updated designs where reprogramming external 28-pin DIP memory is preferable to UV-erasable on-chip ROM, and supports legacy systems built around 8051 external memory interfaces using A0-A15 addressing for up to 64 KB program space.
Which package does the AT80C31X2-RLTUM use, and how does it compare to the DIP version for board layout?
The AT80C31X2-RLTUM is housed in a QFP (Quad Flat Package), a surface mount package with leads on all 4 sides at fine pitch, allowing a much smaller PCB footprint than the 40-pin DIP alternative. QFP SMT placement reduces board height and is compatible with automated reflow soldering, making it preferred in space-constrained embedded designs compared to through-hole DIP versions that require larger holes and more board area.
In what legacy and industrial applications is the AT80C31X2-RLTUM most commonly designed in?
This 8-bit, 40 MHz 8051-compatible MCU is commonly used in legacy industrial controllers, UART-based serial communication adapters, motor speed controllers, and programmable logic controllers (PLCs) that were originally designed around the MCS-51 instruction set. Its compatibility with decades of existing 8051 assembly and C code libraries makes it a drop-in replacement for older AT89 or 80C31 microcontrollers in maintenance upgrades and repair builds.
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