AT89S2051-24PU Microchip Integrated Circuit (Dual-In-Line Packages) In Stock
AT89S2051-24PU is an 8-bit 8051-compatible microcontroller from Microchip with 2 KB Flash, 256 bytes RAM, and a 24 MHz maximum clock in a 20-pin PDIP package. It supports in-system programmable SPI Flash, two 16-bit timers, UART, and 15 I/O lines for straightforward embedded control tasks. Suited for education platforms, legacy system maintenance, and low-cost embedded controllers requiring 8051 compatibility.
- Manufacturer
- Microchip
- Package
- Dual-In-Line Packages
- Pin Count
- 20
- Lifecycle
- OBSOLETE
- Datasheet
- AT89S2051-24PU Datasheet PDF
- Category
- Integrated Circuit
- Temp Range
- -40.0°C to 85.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- 8-bit 8051-compatible CPU running up to 24 MHz
- 2 KB in-system programmable Flash memory
- 256 bytes of internal RAM
- Full-duplex UART for serial communication
- Two 16-bit timer/counters
- 15 programmable I/O lines in 20-pin PDIP package
- SPI-based ISP for field programming without external programmer
Applications
The AT89S2051-24PU is used in education and hobbyist projects as an entry-level 8051-compatible microcontroller that is breadboard-friendly in its 20-pin PDIP package and programmable via a simple SPI ISP interface. It supports legacy industrial equipment maintenance and replacement where 8051 code compatibility is mandatory and hardware redesign is impractical. Low-cost dedicated controllers for relay sequencing, serial data logging, and simple display driving are also common applications.
Specifications
| Pbfree Code | Yes |
| Factory Lead Time | 28Weeks |
| YTEOL | 0 |
| Has ADC | NO |
| Bit Size | 8 |
| Boundary Scan | NO |
| CPU Family | 8051 |
| Clock Frequency-Max | 24MHz |
| DAC Channels | NO |
| DMA Channels | NO |
| Format | FIXED POINT |
| Integrated Cache | NO |
| JESD-30 Code | R-PDIP-T20 |
| JESD-609 Code | e3 |
| Low Power Mode | YES |
| Number of External Interrupts | 2 |
| Number of I/O Lines | 15 |
| Number of Serial I/Os | 1 |
| Number of Timers | 2 |
| On Chip Data RAM Width | 8 |
| On Chip Program ROM Width | 8 |
| PWM Channels | YES |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | DIP20,.3 |
| Package Shape | RECTANGULAR |
| Package Style | IN-LINE |
| Qualification Status | Not Qualified |
| RAM (bytes) | 256 |
| ROM (words) | 2048 |
| ROM Programmability | FLASH |
| Speed | 24MHz |
| Supply Current-Max | 10.5mA |
| Supply Voltage-Max | 5.5V |
| Supply Voltage-Min | 3V |
| Supply Voltage-Nom | 3V |
| Surface Mount | NO |
| Technology | CMOS |
| Temperature Grade | INDUSTRIAL |
| Terminal Finish | MATTE TIN |
| Terminal Form | THROUGH-HOLE |
| Terminal Pitch | 2.54mm |
| Terminal Position | DUAL |
| uPs/uCs/Peripheral ICs Type | MICROCONTROLLER |
| Package | Dual-In-Line Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| HTS Code | 8542.31.00.01 |
| Country of Origin | Thailand |
Alternate & Equivalent Parts
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
How does the AT89S2051-24PU get programmed, and is a separate device programmer required?
The AT89S2051-24PU supports in-system programming (ISP) via a 4-wire SPI interface, allowing it to be programmed directly on the target PCB using a low-cost USB dongle or a microcontroller acting as SPI master. No dedicated high-voltage parallel programmer is required, which simplifies field updates and prototyping at up to 24 MHz operation.
What memory resources are available and are they sufficient for typical 8051 applications?
The device provides 2 KB of ISP Flash for program storage and 256 bytes of internal RAM for data, matching the classic 8051 resource footprint. For simple relay controllers, LED sequencers, and UART communication handlers that typically require under 1.5 KB of code and 100 bytes of data, these resources are fully adequate without external memory expansion.
Which communication peripherals does the AT89S2051-24PU include?
The microcontroller integrates a full-duplex hardware UART supporting standard baud rates up to several hundred kbps at 24 MHz, along with 2 independent 16-bit timer/counters for precise timing events. The 15 programmable I/O lines and SPI ISP port round out the peripheral set for serial sensor interfacing and basic embedded communication tasks.
For which design scenarios is this 20-pin PDIP microcontroller a practical choice over surface-mount alternatives?
The 20-pin PDIP package is preferred for prototyping, education, and through-hole production runs where hand soldering or breadboard insertion is needed. Its 2.54 mm pin pitch and 24 MHz clock speed make it immediately usable in breadboard-based labs without reflow equipment, while 8051 binary compatibility allows reuse of existing firmware libraries and development tools.
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