ATMEGA103L-4AC - 8-Bit AVR MCU 4MHz 128KB TQFP-64 | Microchip
MPN: ATMEGA103L-4AC ✗ Cuối đờiATMEGA103L-4AC Tóm tắt
An 8-bit AVR microcontroller is a single-chip processor that executes most instructions in a single clock cycle using a Harvard-architecture RISC core with 32 general-purpose working registers. Within the system hierarchy, the MCU sits at the heart of an embedded system: flash memory stores program code, SRAM holds runtime variables, and integrated peripherals (UARTs, SPI, timers) interface with sensors and actuators, making a discrete CPU-plus-peripherals chipset unnecessary.
Key features of the ATMEGA103L-4AC include 128 KB (64K x 16) of In-System Programmable (ISP) Flash, dual USARTs for serial communication, an SPI serial interface, two 8-bit and two 16-bit timers/counters with PWM outputs, and an 8-channel external interrupt capability. The AVR core's single-cycle instruction execution yields up to 4 MIPS at the 4 MHz maximum clock rating of this L-suffix (2.7 V to 5.5 V) commercial-grade device.
Architecturally, the ATmega103 separates instruction and data buses, allowing fast register-to-register operations and efficient C-code compilation. External memory expansion (up to 64 KB) is supported through the multiplexed address/data bus on Ports A and C with WR/RD strobes on Port G, enabling designs requiring large data buffers.
Typical applications include legacy industrial control panels, battery-powered instruments, building automation nodes, and embedded systems where the 4 MHz low-voltage rating supports long-battery-life or noise-limited 3.3 V designs.
Design consideration: this part is end-of-life per distributor status data, so new designs should target the ATmega128 family, and existing boards should secure remaining stock or qualify a drop-in variant before replenishment runs out.
This page adds value beyond the manufacturer datasheet by consolidating drop-in alternatives, lifecycle status, pricing context, and practical design notes in one engineer-facing reference.
Bộ thay thế dễ dàng lắp đặt cho ATMEGA103L-4AC — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với ATMEGA103L-4AC (cùng hình factor và footprint) — khác nhau ở Operating Temperature, Maximum Clock Frequency, Package, Flash Program Memory, Instruction Count.
ATMEGA103L-4AI
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ATMEGA103-6AC
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ATMEGA103-6AI
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →ATMEGA103L-4AC Tỷ lệ tối đa & tính chất điện
| Core Processor | AVR |
| Core Size | 8-bit |
| Tần số xung maksimum | 4 MHz |
| Program Memory Size | 128 KB (64K x 16) Flash |
| Program Memory Type | In-System Programmable Flash |
| Operating Voltage Range | 2.7 V to 5.5 V (L-suffix) |
| Supply Voltage Max | 5.5 V |
| Number of I/Os | 48+ |
| Connectivity | SPI, UART |
| Timers | 2 x 8-bit, 2 x 16-bit |
| Hộp | 64-TQFP (14x14 mm) |
| Kiểu lắp đặt | Surface Mount |
| Nhiệt độ hoạt động | 0C to +70C (commercial, C-suffix) |
| Packaging | Tray |
| Product Status | Obsolete |
| External Memory Support | Up to 64 KB |
Cấu hình chân ATMEGA103L-4AC
| Chân 1 | PEN — Programming Enable (active low, programming mode entry) |
| Chân 2 | PE0 — Port E bit 0 / RXD0 (UART0 receive) |
| Chân 3 | PE1 — Port E bit 1 / TXD0 (UART0 transmit) |
| Chân 4 | PE2 — Port E bit 2 / XCK0 (UART0 clock) / AIN0 |
| Chân 5 | PE3 — Port E bit 3 / XCK1 (UART1 clock) / AIN1 |
| Chân 6 | PE4 — Port E bit 4 / INT4 (external interrupt 4) |
| Chân 7 | PE5 — Port E bit 5 / INT5 (external interrupt 5) |
| Chân 8 | PE6 — Port E bit 6 / INT6 (external interrupt 6) |
| Chân 9 | PE7 — Port E bit 7 / INT7 (external interrupt 7) |
| Chân 10 | VCC — Digital supply voltage |
| Chân 11 | GND — Ground |
| Chân 12 | PB0 — Port B bit 0 / SS (SPI slave select) |
| Chân 13 | PB1 — Port B bit 1 / SCK (SPI clock) |
| Chân 14 | PB2 — Port B bit 2 / MOSI (SPI master out) |
| Chân 15 | PB3 — Port B bit 3 / MISO (SPI master in) |
| Chân 16 | PB4 — Port B bit 4 / OC0 (Timer0 compare output) |
| Chân 17 | PB5 — Port B bit 5 / OC1A (Timer1 compare output A) |
| Chân 18 | PB6 — Port B bit 6 / OC1B (Timer1 compare output B) |
| Chân 19 | PB7 — Port B bit 7 / OC2 (Timer2 compare output) |
| Chân 20 | VCC — Digital supply voltage |
| Chân 21 | GND — Ground |
| Chân 22 | PD0 — Port D bit 0 / INT0 (external interrupt 0) |
| Chân 23 | PD1 — Port D bit 1 / INT1 (external interrupt 1) |
| Chân 24 | PD2 — Port D bit 2 / INT2 (external interrupt 2) |
| Chân 25 | PD3 — Port D bit 3 / INT3 (external interrupt 3) |
| Chân 26 | PD4 — Port D bit 4 / ICP1 (Timer1 input capture) |
| Chân 27 | PD5 — Port D bit 5 / OC1A (Timer1 compare output A, alternate) |
| Chân 28 | PD6 — Port D bit 6 / OC1B (Timer1 compare output B, alternate) |
| Chân 29 | PD7 — Port D bit 7 / OC2 (Timer2 compare output, alternate) |
| Chân 30 | RESET — Reset input (active low) |
| Chân 31 | PC0 — Port C bit 0 / external memory address A8 |
| Chân 32 | PC1 — Port C bit 1 / external memory address A9 |
| Chân 33 | PC2 — Port C bit 2 / external memory address A10 |
| Chân 34 | PC3 — Port C bit 3 / external memory address A11 |
| Chân 35 | PC4 — Port C bit 4 / external memory address A12 |
| Chân 36 | PC5 — Port C bit 5 / external memory address A13 |
| Chân 37 | PC6 — Port C bit 6 / external memory address A14 |
| Chân 38 | PC7 — Port C bit 7 / external memory address A15 |
| Chân 39 | PG0 — Port G bit 0 / WR (external memory write strobe) |
| Chân 40 | PG1 — Port G bit 1 / RD (external memory read strobe) |
| Chân 41 | PG2 — Port G bit 2 / TOSC1 (Timer oscillator input) |
| Chân 42 | PG3 — Port G bit 3 / TOSC2 (Timer oscillator output) |
| Chân 43 | PF0 — Port F bit 0 (general purpose I/O) |
| Chân 44 | PF1 — Port F bit 1 (general purpose I/O) |
| Chân 45 | PF2 — Port F bit 2 (general purpose I/O) |
| Chân 46 | PF3 — Port F bit 3 (general purpose I/O) |
| Chân 47 | PF4 — Port F bit 4 (general purpose I/O) |
| Chân 48 | PF5 — Port F bit 5 (general purpose I/O) |
| Chân 49 | PF6 — Port F bit 6 (general purpose I/O) |
| Chân 50 | PF7 — Port F bit 7 (general purpose I/O) |
| Chân 51 | PA0 — Port A bit 0 / external memory AD0 (multiplexed address/data) |
| Chân 52 | PA1 — Port A bit 1 / external memory AD1 |
| Chân 53 | PA2 — Port A bit 2 / external memory AD2 |
| Chân 54 | PA3 — Port A bit 3 / external memory AD3 |
| Chân 55 | PA4 — Port A bit 4 / external memory AD4 |
| Chân 56 | PA5 — Port A bit 5 / external memory AD5 |
| Chân 57 | PA6 — Port A bit 6 / external memory AD6 |
| Chân 58 | PA7 — Port A bit 7 / external memory AD7 |
| Chân 59 | PG4 — Port G bit 4 (general purpose I/O) |
| Chân 60 | PG5 — Port G bit 5 (general purpose I/O) |
| Chân 61 | NC — Not connected (per datasheet) |
| Chân 62 | NC — Not connected (per datasheet) |
| Chân 63 | GND — Ground |
| Chân 64 | VCC — Digital supply voltage |
Ứng dụng tiêu biểu
ATMEGA103L-4AC phù hợp cho 6 Áp dụngs: Industrial Control Panels, Battery-Powered Instruments, Building Automation Nodes, Legacy Embedded System Repair, Test and Measurement Fixtures, Security and Access Control Systems.
Industrial Control Panels
The ATMEGA103L-4AC fits industrial control panels where its 128 KB Flash accommodates large ladder-logic interpreters or HMI code, and its dual UARTs link to PLC backbones and operator displays. The AVR core executes most instructions in one cycle at 4 MHz, providing deterministic response for relay and actuator sequencing, while eight external interrupts on Ports D and E handle limit-switch and safety-input events with low latency. Its external memory interface (up to 64 KB via Ports A, C, and G) supports datalogging buffers that 64 KB-class MCUs cannot hold internally. Because the commercial-grade AC part is rated 0C to +70C, cabinet-mounted installations are appropriate; field-mounted units should use the ATMEGA103L-4AI industrial variant with identical pinout.
Được đề xuất
Battery-Powered Instruments
For portable instruments, the ATMEGA103L-4AC's L-suffix 2.7 V supply rating allows direct operation from 3 V lithium cells, and the 4 MHz clock ceiling keeps active current low compared with 16 MHz-class MCUs. The 128 KB ISP Flash permits field firmware updates through the SPI interface without desoldering, extending service life of deployed units, while AVR sleep modes described in the Atmel datasheet cut standby consumption between measurements. One 16-bit timer can gate sensor acquisition, and a UART streams logged data to a PC. Designers should budget the 64-TQFP's peripheral count (48+ I/O) for keypad, LCD, and sensor interfaces, and select the ATMEGA103L-4AI variant when the instrument must operate below 0C.
Được đề xuất
Building Automation Nodes
Building automation nodes benefit from the ATMEGA103L-4AC's dual USARTs: one handles an RS-485 multidrop field bus while the second services a local service port for diagnostics. The SPI port interfaces to external EEPROM or digital sensors, and the 128 KB Flash stores communication stacks plus schedule tables that smaller AVRs cannot fit. With 2.7 V to 5.5 V operation, the node tolerates supply variation in distributed wiring, and the 64-TQFP 14x14 mm footprint mounts on standard single-size node boards. Because this part is obsolete, new node designs should target the ATmega128 family, but for maintaining installed fleets, this MPN and its drop-in ATMEGA103L-4AI sibling remain the repair parts of choice.
Được đề xuất
Legacy Embedded System Repair
The primary remaining use of the ATMEGA103L-4AC is repairing installed embedded systems designed in the late 1990s and early 2000s around the ATmega103. In this scenario the pinout must match exactly, which rules out ATmega128 and mandates ATMEGA103-family variants such as ATMEGA103L-4AI (same die, industrial grade) or ATMEGA103-6AC (6 MHz speed upgrade, same package). The 128 KB ISP Flash means replacement units can be pre-programmed off-board with the original firmware image via SPI before soldering, minimizing downtime. Since distributor status is obsolete, repair depots should buy final quantities now; XAIPART lists verified drop-in alternatives with parametric match percentages to support last-time-buy decisions.
Được đề xuất
Test and Measurement Fixtures
Automated test fixtures use the ATMEGA103L-4AC as a fixture controller: its four timers with PWM outputs generate stimulus signals, eight external interrupts capture device-under-test responses, and dual UARTs report results over serial while a second channel commands a relay matrix. The 48+ general-purpose I/O lines of the 64-TQFP drive LED arrays, multiplexers, and switches without glue logic, and the external memory interface buffers long result datasets when fitted with 32 to 64 KB of SRAM. At 4 MHz with single-cycle execution, timing loops are deterministic, which matters for go/no-go timing tests. Benches are within the 0C to +70C commercial rating of the AC grade.
Được đề xuất
Security and Access Control Systems
Access control panels leverage the ATMEGA103L-4AC's combination of large Flash and plentiful I/O: 128 KB holds keypad scanning, card-format decoding, event logging, and a modest communication stack simultaneously, while dozens of port pins interface keypads, magnetic locks, and door sensors directly. Dual UARTs separate the reader interface from the upstream alarm-panel link, and the external interrupt bank timestamps door events precisely for audit trails. The 2.7 V to 5.5 V range accepts battery-backed supplies during mains loss. Because the device is obsolete, integrators maintaining these systems should standardize on the pin-compatible ATMEGA103L-4AI and verify programming fixtures support ATmega103 SPI ISP before bulk replacement.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho ATMEGA103L-4AC — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | ATMEGA103L-4AI | ATMEGA103-6AC | ATMEGA103-6AI |
|---|---|---|---|---|
| Package | 64-TQFP (14x14 mm) | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same |
| Brand | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 128 KB | 128 KB | 128 KB | 128 KB |
| Max Clock Speed | 4 MHz | 4 MHz | 6 MHz | 6 MHz |
| Operating Voltage | 2.7 V to 5.5 V (L grade) | 2.7 V to 5.5 V (L grade) | 4.0 V to 5.5 V | 4.0 V to 5.5 V |
| Temperature Range | 0C to +70C (commercial) | -40C to +85C (industrial) | 0C to +70C (commercial) | -40C to +85C (industrial) |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete |
| Pin Compatibility | Reference (AVR ATmega103 64-TQFP) | Pin-to-pin identical | Pin-to-pin identical | Pin-to-pin identical |
Bảo phân biệt quan trọng
- Lowest-voltage operation in the ATmega103 family (vsATMEGA103-6AC)
- Largest 128 KB on-chip Flash in its era (vsATMEGA8L-8AU)
- Cheapest repair option vs architectural migration (vsATMEGA128L-8AU)
Ghi chú thiết kế
Decouple every VCC pin (pins 10, 20, 64) with a 100 nF ceramic capacitor placed within 5 mm of the pin, plus one bulk 10 uF capacitor per supply rail. The L-suffix 2.7 V floor leaves little margin on 3 V battery rails: Estimated - at 4 MHz the ATmega103 active current is on the order of a few mA, so a dropped cell voltage near 2.8 V approaches the brownout boundary; enable the datasheet Brown-out Detector if firmware integrity across supply dips matters.
The 64-TQFP 0.8 mm pitch leads require a standard 14x14 mm land pattern per the package drawing in the Atmel datasheet. If external memory is fitted, keep the PA0-PA7 AD bus and PC0-PC7 address bus under 10 cm with series 22-33 ohm resistors to control ringing; latch the low address byte with a 74HC573 on the ALE/AS signal early in the layout. Avoid routing the RESET trace near the SPI SCK line to prevent accidental ISP mode entry.
Do not assume ATmega128 is a pin-for-pin replacement: PORTG and several peripheral multiplex functions differ between ATmega103 and ATmega128 despite the same 64-TQFP footprint. Also, the AC suffix is commercial grade only - deploying at outdoor temperatures requires the AI variant. Finally, this part is obsolete: before releasing a repair batch, verify genuine date codes, as the broker market for ATmega103 carries elevated counterfeit risk; buy from authorized or inspected excess stock only.
Thông tin tuân thủ
The ATmega103 predates RoHS-era documentation; the verified web data does not state RoHS/REACH/lead-free status for this MPN, so all compliance fields are unknown pending Microchip archive confirmation.