Microchip Technology ATMEGA128RFR2-ZFR

Overview

ATMEGA128RFR2-ZFR from Microchip Technology (formerly Atmel) is an 8-bit AVR microcontroller integrated with a 2.4 GHz IEEE 802.15.4/ZigBee transceiver in a single QFN-64 package. It delivers 128 KB Flash, 4 KB EEPROM, 16 KB SRAM, 38 programmable I/O lines, and hardware-accelerated MAC functionality - enabling self-contained wireless sensor node design for low-power mesh networks.

For engineers reviewing the ATMEGA128RFR2-ZFR datasheet, ATMEGA128RFR2-ZFR pinout, ATMEGA128RFR2-ZFR application, or ATMEGA128RFR2-ZFR equivalent, key selection criteria include its integrated 2.4 GHz transceiver with -100 dBm RX sensitivity, 3.5 dBm TX output, hardware AES encryption, 32-bit IEEE 802.15.4 symbol counter, and ultra-low deep-sleep current of <700 nA at 25°C.

Technical Context

The ATMEGA128RFR2-ZFR combines an enhanced RISC AVR core (135 instructions, 32 general-purpose registers, 16 MIPS @ 16 MHz) with a fully integrated 2.4 GHz DSSS transceiver featuring fractional-N PLL synthesizer, hardware-assisted MAC (auto-ack, auto-retry), and 32-byte RX/TX frame buffers. Its dual-oscillator system uses 16 MHz crystal (XTAL1/XTAL2) for RF timing and 32.768 kHz crystal (TOSC1/TOSC2) for low-power symbol counting and RTC.

It supports IEEE 802.15.4-2011/2006/2003 and ZigBee protocols with data rates up to 2 Mb/s, hardware CRC-16, SFD detection, spreading/despreading, and antenna diversity control via DIG1/DIG2 pins. Power management includes six software-selectable sleep modes, with deep sleep consuming <700 nA while retaining MAC symbol counter and 32.768 kHz oscillator operation.

Key Specifications

Pinout & Package

ATMEGA128RFR2-ZFR is housed in a 64-pad QFN (RoHS/Fully Green) package with exposed metal paddle internally connected to AVSS. The paddle must be soldered to PCB ground for mechanical stability and thermal performance; leaving it unconnected risks package detachment.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 2.4 GHz wireless microcontroller applications.

Compared with ATMEGA128RFR2-ZFR, ATMEGA256RFR2-ZUR offers scalable memory for complex coordinator roles without changing RF design or layout, while CC2652R1F provides broader protocol flexibility and higher compute headroom at the cost of increased power and toolchain migration effort.

Availability

ATMEGA128RFR2-ZFR is available at Aetrix Electronics and suitable for smart utility metering, industrial sensor networks, building automation systems, and ZigBee Pro router deployments requiring stable component supply across extended product lifecycles.

Supply support for ATMEGA128RFR2-ZFR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology acquired Atmel in 2016 and maintains full support for the AVR wireless portfolio. The company specializes in microcontrollers, analog, FPGA, and connectivity solutions for industrial, automotive, and IoT markets.

ATMEGA128RFR2-ZFR belongs to the Atmel AVR RFR2 family - designed specifically for IEEE 802.15.4 and ZigBee-compliant wireless embedded systems where integration, ultra-low power, and hardware protocol acceleration are critical.

FAQ

What is the maximum transmit output power of the ATMEGA128RFR2-ZFR transceiver?

The ATMEGA128RFR2-ZFR transceiver delivers up to +3.5 dBm output power in the 2.4 GHz ISM band. This value is measured under typical conditions (3.0 V supply, 25°C ambient) and enables reliable communication over distances exceeding 100 meters in open-air environments. The actual output can be reduced in software to meet regulatory limits or extend battery life, and the hardware supports automatic power control during transmission.

Does the ATMEGA128RFR2-ZFR support hardware AES encryption?

Yes, the ATMEGA128RFR2-ZFR includes a dedicated hardware AES-128 encryption/decryption engine and a true random number generator. These peripherals operate independently of the AVR CPU, allowing secure key derivation, encrypted frame payloads, and authenticated bootloading without compromising real-time performance. The AES module is accessible via dedicated I/O registers and supports ECB and CTR modes per IEEE 802.15.4 security requirements.

What are the supported data rates for the ATMEGA128RFR2-ZFR radio?

The ATMEGA128RFR2-ZFR supports IEEE 802.15.4-compliant data rates of 250 kb/s, 500 kb/s, 1 Mb/s, and 2 Mb/s. All rates use Direct Sequence Spread Spectrum (DSSS) modulation with O-QPSK encoding. The 250 kb/s mode provides best link budget (-100 dBm sensitivity), while higher rates trade sensitivity for throughput - e.g., 2 Mb/s achieves ~94 dBm sensitivity. Rate selection is configured in firmware and affects both PHY layer behavior and MAC timing parameters.

Can the ATMEGA128RFR2-ZFR operate across the full industrial temperature range?

Yes, the ATMEGA128RFR2-ZFR is rated for continuous operation from -40°C to +125°C. This specification is validated per JEDEC standards and includes guaranteed performance of both the AVR core (16 MHz max at 1.8–3.6 V) and RF transceiver (RX sensitivity, TX output, PLL lock time). The device uses internal voltage regulation and temperature-compensated oscillators to maintain timing accuracy and RF stability across this range - making it suitable for smart meters, industrial sensors, and outdoor gateways.

How many GPIO pins does the ATMEGA128RFR2-ZFR provide?

The ATMEGA128RFR2-ZFR provides 38 programmable I/O lines distributed across Ports B, D, E, F, G, and dedicated RF control pins. Port B (8 pins), Port D (8), Port E (8), Port F (8), and Port G (6) are fully functional bidirectional I/O with internal pull-ups. Additional pins like RSTON, TST, CLKI, and RF control signals (DIG1–DIG4, AMR) serve specific system functions but are not general-purpose. Unused GPIOs must be tied to valid logic levels to prevent leakage current.