ATMEGA169L-4AC - 8-bit AVR MCU 16KB LCD 4MHz | Microchip
MPN: ATMEGA169L-4AC β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.2 | $6.20 |
| 10 | $5.58 | $55.80 |
| 100 | $4.96 | $496.00 |
| 500 | $4.34 | $2,170.00 |
| 1,000 | $3.72 | $3,720.00 |
ATMEGA169L-4AC Overview
An AVR 8-bit microcontroller is a member of the broader microcontroller (MCU) family within the embedded processor hierarchy: MCU -> microcontroller unit -> AVR RISC microcontroller -> embedded system controller. AVR cores execute most of their 130 powerful instructions in a single clock cycle, combining high code density with low power consumption, which is why AVR MCUs remain popular in cost-sensitive embedded designs.
Key features of the ATMEGA169L-4AC include Advanced RISC Architecture with 32 general-purpose working registers, In-System Programmable Flash with Read-While-Write capability, a JTAG interface for boundary-scan, on-chip debugging, and programming, and a complete on-chip LCD controller with internal step-up voltage generator. The internal oscillator eliminates the need for an external crystal in many designs, reducing bill-of-materials cost.
Technically, the device pairs the classic AVR Harvard architecture with a rich peripheral set: three flexible timers, a built-in LCD driver capable of driving segmented LCD panels directly, and 53 programmable I/O lines. The 4 MHz speed grade with the L (low-voltage) designation targets battery-powered and low-voltage designs where the higher-speed ATMEGA169P/V variants are unnecessary.
Typical applications include battery-operated instruments with segmented LCD displays, utility meters, handheld measurement devices, industrial control panels, and appliance user interfaces. The integrated LCD controller is the primary differentiator versus the general-purpose ATmega168 family.
Design consideration: verify the operating voltage window of the L speed grade against your supply rail and confirm JTAG fuse settings before locking the device, since JTAG double duty as debug port and I/O can surprise first-time users.
This page synthesizes distributor pricing context, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA169L-4AC β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ATMEGA169L-4AC (same form factor and footprint) β differing in Instruction Set, LCD Controller.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA169L-4AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA169V-8AC
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA169P-16AC
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA169PA-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA169PV-8AU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$2.98 / Unit
View Datasheet βATMEGA169L-4AC Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Max Clock Frequency | 4 MHz |
| Program Memory Size | 16KB (8K x 16) Flash |
| Program Memory Type | In-System Programmable Flash, Read-While-Write |
| SRAM Size | 1KB (1K x 8) |
| EEPROM Size | 512 bytes |
| Number of I/O | 53 |
| Oscillator Type | Internal |
| LCD Controller | On-chip LCD controller with internal step-up voltage |
| JTAG Interface | Boundary-scan, On-chip Debug, Programming |
| Instruction Set | 130 powerful instructions, most single-cycle |
| Working Registers | 32 general purpose |
| Timers | 3 flexible timers |
| Package / Case | 64-TQFP (14 x 14 mm) |
| Mounting Type | Surface Mount |
| Packaging | Tray |
ATMEGA169L-4AC 64-tqfp (14 x 14 mm) Pin Configuration Guide
Pin configuration for ATMEGA169L-4AC (64-tqfp (14 x 14 mm) package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for ATMEGA169L-4AC.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA169L-4AC is suitable for 6 applications: Battery-Powered LCD Instruments, Utility Metering and Submetering, Industrial Control Panels, Appliance User Interfaces, Handheld Measurement Devices, Embedded Learning and Legacy Maintenance.
Battery-Powered LCD Instruments
The ATMEGA169L-4AC's defining feature for this application is its complete on-chip LCD controller with internal step-up voltage, which drives segmented LCD glass directly without an external LCD driver or charge-pump IC. The 4 MHz low-voltage L speed grade keeps dynamic current low, and the internal oscillator removes crystal start-up energy from the power budget. In a typical handheld meter, the MCU drives the LCD, samples buttons or an ADC front-end, and sleeps between refreshes. The LCD step-up generator maintains contrast even as the battery discharges, extending usable battery life compared with passive drive schemes powered from the raw rail.
Recommended
Utility Metering and Submetering
Energy and utility meters require a numeric or segmented display, long battery or auxiliary-power life, and reliable non-volatile storage - all addressed by the ATMEGA169L-4AC. The 512B EEPROM stores calibration constants and billing registers through power cycles, while the 16KB ISP Flash with Read-While-Write supports field firmware updates. The on-chip LCD controller drives tariff and consumption digits directly, and 53 I/O lines interface pulse inputs, relays, and communication transceivers. The 4 MHz operating point delivers 4 MIPS, ample for metering algorithms, and the JTAG interface supports production boundary-scan test of the assembled meter board.
Recommended
Industrial Control Panels
Industrial panels need status display, user input, and robust I/O - the ATMEGA169L-4AC combines a directly driven segmented LCD with 53 general-purpose I/O lines suitable for driving relays, reading limit switches, and bit-banging serial links. Three flexible timers generate PWM outputs for actuators or measure input frequencies from sensors. The 130-instruction AVR RISC core executes most instructions in a single 4 MHz clock cycle, giving deterministic 4 MIPS throughput adequate for scan-based panel logic. JTAG boundary-scan simplifies production test of dense TQFP assemblies, and the internal oscillator removes a component that could fail under panel vibration.
Recommended
Appliance User Interfaces
Washer, oven, and climate-control interfaces pair an LCD segment display with buttons and actuators - exactly the ATMEGA169L-4AC's strength profile. The on-chip LCD controller with internal step-up voltage drives multi-digit glass from a single supply, cutting BOM cost versus discrete driver ICs, while the 1KB SRAM buffers display frames and menu state. The 16KB Flash accommodates localization strings and state machines, and EEPROM retains user settings across power loss. The 64-TQFP 14 x 14 mm footprint suits cost-driven two-layer appliance boards, and the internal oscillator tolerates the wide temperature environments of kitchen and HVAC enclosures.
Recommended
Handheld Measurement Devices
Portable multimeters, environmental meters, and diagnostic tools benefit from the ATMEGA169L-4AC's balance of low-voltage 4 MHz operation, integrated LCD drive, and JTAG-based on-chip debugging that shortens firmware bring-up. The 53 I/O lines connect an ADC front end, rotary encoders, and buzzer outputs, while three timers handle measurement gating and audible feedback. EEPROM stores calibration data that survives battery replacement, and the Read-While-Write Flash permits safe in-field upgrades. Compared with adding an external LCD driver to a generic MCU, the single-chip approach reduces board area and quiescent drain, directly extending the interval between battery swaps in field instruments.
Recommended
Embedded Learning and Legacy Maintenance
The ATmega169 is a classic AVR teaching platform, and the ATMEGA169L-4AC remains relevant for maintaining legacy training boards and products already designed around it. The AVR architecture - 32 general-purpose registers, 130 mostly single-cycle instructions - is approachable in assembly and C, and the JTAG interface supports on-chip debugging with standard Atmel/Microchip tools, letting students watch registers in real time. For maintenance engineering, the pin-compatible family ladder (L, V, P, PA grades in the same 64-TQFP) allows requalification to available speed grades without PCB respin, which is the practical path when the exact 4 MHz L grade becomes constrained in the open market.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA169L-4AC β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA169L-4AU | ATMEGA169V-8AC | ATMEGA169P-16AC | ATMEGA169PA-AU |
|---|---|---|---|---|---|
| Package | 64-TQFP (14 x 14 mm) | 64-TQFP (14 x 14 mm) - same | 64-TQFP (14 x 14 mm) - same | 64-TQFP (14 x 14 mm) - same | 64-TQFP (14 x 14 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Clock Frequency | 4 MHz | 4 MHz | 8 MHz | 16 MHz | 16 MHz |
| Flash Memory | 16KB (8K x 16) | 16KB (8K x 16) | 16KB (8K x 16) | 16KB (8K x 16) | 16KB (8K x 16) |
| SRAM | 1KB | 1KB | 1KB | 1KB | 1KB |
| EEPROM | 512 bytes | 512 bytes | 512 bytes | 512 bytes | 512 bytes |
| I/O Count | 53 | 53 | 53 | 53 | 53 |
| LCD Controller | Yes, on-chip with step-up | Yes, on-chip with step-up | Yes, on-chip with step-up | Yes, on-chip with step-up | Yes, on-chip with step-up |
| Low-Power Feature | Standard L grade | Standard L grade | Standard V grade | Standard P grade | picoPower sleep modes |
Key Differentiators
- Integrated LCD controller with internal step-up voltage (vs ATMEGA168PB-AUR)
- Lowest-cost operating point in the ATmega169 family (vs ATMEGA169P-16AC)
- Family ladder enables no-respin requalification (vs ATMEGA169PA-AU)
Design Notes
JTAG pin sharing is the most common first-design error on the ATmega169. When the JTAGEN fuse is programmed, the JTAG pins (TDI, TDO, TMS, TCK) are dedicated to the debug/boundary-scan port and cannot serve as general-purpose I/O, reducing the effective I/O count below 53. If your application needs all 53 I/O, you can disable JTAG via fuse after production programming, but then on-chip debugging is lost. Decide the JTAG strategy during schematic capture, not at programming time, and consult the fuse tables in the manufacturer datasheet.
The L speed grade is rated 4 MHz, and AVR throughput is approximately 1 MIPS per MHz, so budget 4 MIPS of worst-case compute. If firmware timing analysis shows headroom risk, the pin-compatible ATMEGA169V-8AC or P-16AC grades double or quadruple throughput on the identical 64-TQFP footprint with no PCB change - but confirm the speed-versus-voltage derating curve in the datasheet for your actual supply rail before substituting, since higher grades impose minimum voltage requirements at maximum frequency.
For the LCD controller, keep LCD drive traces (SEG/LCD bias lines) away from high-dv/dt switching nets to avoid ghost segments; route bias capacitor nodes short and direct, and follow the datasheet's recommended capacitor values for the internal step-up generator. Decouple VCC/AVCC with 100 nF ceramics placed within a few millimeters of each supply pin pair on the 64-TQFP. Because the internal oscillator removes the crystal, reserve an external-clock option in layout if future timing accuracy (e.g., UART baud tolerance) may require a crystal or resonator.
Compliance Information
Compliance status not stated in the retrieved web data; verify RoHS/REACH on the official Microchip product page or the etei.com comparison listings before export documentation.