AT89S51-33PU Microchip Integrated Circuit (Dual-In-Line Packages) In Stock
Microchip AT89S51-33PU is an 8-bit 8051-family microcontroller featuring 4 KB of in-system programmable Flash memory and running up to 33 MHz. It integrates a 16-bit address bus, 4 I/O ports, and serial UART on a 40-pin DIP package. Available in stock from authorized distributors with worldwide shipping.
- Manufacturer
- Microchip
- Package
- Dual-In-Line Packages
- Pin Count
- 40
- Lifecycle
- ACTIVE
- Datasheet
- AT89S51-33PU 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
What are the key features of AT89S51-33PU?
- 4 KB in-system programmable Flash with 1000 write/erase cycles for easy field updates
- 8051-compatible core running at up to 33 MHz clock frequency for real-time control tasks
- 40-pin DIP package with 4 full 8-bit I/O ports (32 I/O lines) and on-chip UART
- SPI-based ISP programming interface enabling in-circuit firmware updates without a dedicated programmer
What is AT89S51-33PU used for?
The AT89S51-33PU is ideal for embedded control systems such as industrial automation panels, home appliance controllers, and educational prototyping platforms requiring a low-cost 8-bit MCU. Its 8051 instruction-set compatibility allows straightforward migration from legacy MCS-51 designs while gaining in-system programmability. The 40-pin DIP format suits breadboard and through-hole PCB prototyping for sensor interfacing and serial communication projects.
What are the specifications of AT89S51-33PU?
| YTEOL | 6 |
| Has ADC | NO |
| Address Bus Width | 16 |
| Bit Size | 8 |
| Boundary Scan | NO |
| CPU Family | 8051 |
| Clock Frequency-Max | 33MHz |
| DAC Channels | NO |
| DMA Channels | NO |
| External Data Bus Width | 8 |
| JESD-30 Code | R-PDIP-T40 |
| Number of I/O Lines | 32 |
| On Chip Program ROM Width | 8 |
| PWM Channels | NO |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | DIP40,.6 |
| Package Shape | RECTANGULAR |
| Package Style | IN-LINE |
| Qualification Status | Not Qualified |
| RAM (bytes) | 128 |
| ROM (words) | 4096 |
| ROM Programmability | FLASH |
| Speed | 33MHz |
| Supply Current-Max | 25mA |
| Supply Voltage-Max | 5.5V |
| Supply Voltage-Min | 5V |
| Supply Voltage-Nom | 5V |
| Surface Mount | NO |
| Technology | CMOS |
| Temperature Grade | INDUSTRIAL |
| Terminal Form | THROUGH-HOLE |
| Terminal Pitch | 2.54mm |
| Terminal Position | DUAL |
| uPs/uCs/Peripheral ICs Type | MICROCONTROLLER |
| ## AT89S51-33PU Alternates Showing results | Image |
| Package | Dual-In-Line Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| ECCN | 3A991.a.2 |
| HTS Code | 8542.31.00.15 |
| Country of Origin | Thailand |
Where can I find the AT89S51-33PU datasheet?
AT89S51-33PU Datasheet DownloadOfficial datasheet from Microchip
What are equivalent replacements for AT89S51-33PU?
Compatible alternatives and drop-in replacements for AT89S51-33PU:
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Frequently Asked Questions
How fast can the AT89S51-33PU execute instructions and what clock source does it require?
The AT89S51-33PU operates at up to 33 MHz using an external crystal or clock source, executing a full 8051 machine cycle in 12 oscillator periods. At maximum speed this yields approximately 2.75 million instructions per second, sufficient for real-time sensor polling and serial communication tasks at standard baud rates up to 115200 bps.
What programming method does the AT89S51-33PU support for field firmware updates?
The AT89S51-33PU supports SPI-based in-system programming (ISP) allowing firmware to be updated directly on the PCB without removing the device. The 4 KB Flash endures at least 1000 write/erase cycles, and a 128-byte RAM provides working memory during ISP operations. This makes field maintenance practical for deployed industrial controllers.
For a legacy 8051 design migration, how pin-compatible is the AT89S51-33PU with earlier MCS-51 devices?
The AT89S51-33PU is architecturally compatible with the standard 8051 instruction set and uses the same 40-pin DIP pinout as classic MCS-51 devices. It retains 4 bidirectional 8-bit I/O ports, one full-duplex UART, two 16-bit timers, and external memory expansion support via the 16-bit address bus, making drop-in migration from older 12 MHz variants straightforward.
What on-chip memory resources are available in the AT89S51-33PU for data and code storage?
The AT89S51-33PU provides 4 KB of in-system programmable Flash for program storage and 128 bytes of on-chip data RAM for runtime variables. It also includes 2 KB of ROM-based boot loader. External memory expansion up to 64 KB is possible through the 16-bit address bus and 8-bit data bus, accommodating larger data logging or display buffer requirements.
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