| PartNumber | AT89LP51-20AU | AT89LP51-20JU | AT89LP51-20MU |
| Description | 8-bit Microcontrollers - MCU Single Cycle 8051 4K ISP FL | 8-bit Microcontrollers - MCU Single Cycle 8051 4K ISP FL | 8-bit Microcontrollers - MCU Single Cycle 8051 4K ISP FL |
| Manufacturer | Microchip | Microchip | Microchip |
| Product Category | 8-bit Microcontrollers - MCU | 8-bit Microcontrollers - MCU | 8-bit Microcontrollers - MCU |
| RoHS | Y | Y | Y |
| Package / Case | TQFP-44 | PLCC-44 | VQFN-44 |
| Core | 8051 | 8051 | 8051 |
| Data Bus Width | 8 bit | 8 bit | 8 bit |
| Maximum Clock Frequency | 20 MHz | 20 MHz | - |
| Program Memory Size | 4 kB | 4 kB | - |
| Data RAM Size | 256 B | 256 B | - |
| ADC Resolution | No ADC | No ADC | - |
| Number of I/Os | 36 I/O | - | - |
| Operating Supply Voltage | 2.4 V to 5.5 V | 2.4 V to 5.5 V | - |
| Minimum Operating Temperature | - 40 C | - 40 C | - |
| Maximum Operating Temperature | + 85 C | + 85 C | - |
| Packaging | Tray | Tube | Tray |
| Product | MCU | - | - |
| Program Memory Type | Flash | Flash | - |
| Brand | Microchip Technology / Atmel | Microchip Technology / Atmel | Microchip Technology / Atmel |
| Data RAM Type | SRAM | - | - |
| Data ROM Size | 256 B | 256 B | - |
| Data ROM Type | EEPROM | - | - |
| Interface Type | 2-Wire, SPI, UART | UART | - |
| Analog Supply Voltage | - | - | - |
| DAC Resolution | - | - | - |
| I/O Voltage | - | - | - |
| Moisture Sensitive | Yes | Yes | Yes |
| Number of ADC Channels | - | - | - |
| Number of Timers/Counters | 3 Timer | 3 Timer | - |
| Processor Series | AT89LP51 Series | - | - |
| Product Type | 8-bit Microcontrollers - MCU | 8-bit Microcontrollers - MCU | 8-bit Microcontrollers - MCU |
| Factory Pack Quantity | 160 | 27 | 360 |
| Subcategory | Microcontrollers - MCU | Microcontrollers - MCU | Microcontrollers - MCU |
| Supply Voltage Max | 5.5 V | 5.5 V | - |
| Supply Voltage Min | 2.4 V | 2.4 V | - |
| Watchdog Timers | Watchdog Timer | - | - |
| Mounting Style | - | SMD/SMT | - |
| Unit Weight | - | 0.084185 oz | - |