Microchip Technology ATA5790-P3QW 18

Overview

ATA5790-P3QW from Microchip Technology (formerly Atmel) is a smart Passive Entry/Passive Start (PEPS) transponder IC integrating an ultra-low-power 8-bit AVR microcontroller, 3D 125kHz LF receiver, AES-128 cryptographic engine, and immobilizer interface in a single QFN38 package. It delivers wake-up sensitivity of 1.3mVpp, 4µA listen-mode current, and operates from 1.9V to 4.2V across –40°C to +85°C for automotive key fob applications.

For engineers reviewing the ATA5790-P3QW datasheet, ATA5790-P3QW pinout, ATA5790-P3QW application, or ATA5790-P3QW equivalent, key selection considerations include LF channel count (3-axis), integrated crypto acceleration, EEPROM protection via ECC, and compatibility with contactless immobilizer protocols requiring 125kHz field coupling and secure key exchange.

Technical Context

The ATA5790-P3QW implements a system-on-chip architecture combining three independent 125kHz LF receiver channels with logarithmic 8-bit digital RSSI for simultaneous field strength measurement, enabling robust 3D proximity detection in PEPS systems. Its integrated AVR core executes both immobilizer stack firmware and custom application logic using 16KB flash (including 2KB pre-certified software) and 2112-byte EEPROM with ECC protection.

Power management includes dual RC oscillators (125kHz and 4MHz), programmable voltage monitor, POR/BOD, and RTC - supporting ultra-low-power states: 0.8µA power-down, 50µA active at 125kHz system clock, and 4µA LF receiver listen mode. The AES-128 engine is accessible by both LF transponder and PEPS units for mutual authentication.

Key Specifications

Pinout & Package

ATA5790-P3QW is housed in a Pb-free 5mm × 7mm QFN38 package with 0.5mm pitch and exposed thermal pad (3.6mm × 5.6mm). Pin 1 is marked by a dot; pins are arranged in two rows (19 per side) with GND on multiple corners and edges for optimal noise immunity in LF-sensitive designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transponder microcontroller applications.

Compared with PCF7961 and SLB9670, ATA5790-P3QW uniquely integrates 3D LF sensing, AVR execution, and AES-128 crypto in one die - eliminating inter-chip latency, reducing BOM count, and enabling true single-chip PEPS key implementation without external coordination.

Availability

ATA5790-P3QW is available at Aetrix Electronics and suitable for automotive key fobs, passive entry systems, and immobilizer transponders requiring stable component supply, long-term lifecycle support, and AEC-Q100-aligned reliability.

Supply support for ATA5790-P3QW 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 its automotive-qualified mixed-signal IC portfolio, emphasizing security, low power, and system integration for automotive electronics.

The ATA5790-P3QW belongs to Atmel's automotive transponder microcontroller family, designed specifically to consolidate passive entry, passive start, and immobilizer functionality into a single chip for next-generation key fobs.

FAQ

What is the primary function of the ATA5790-P3QW in automotive key systems?

The ATA5790-P3QW serves as a fully integrated transponder microcontroller for Passive Entry/Passive Start (PEPS) and immobilizer applications. It combines a 3D 125kHz LF receiver, ultra-low-power AVR core, AES-128 crypto engine, and protected memory - enabling secure, battery-efficient key fobs that authenticate and authorize vehicle access and ignition without user interaction. ATA5790-P3QW replaces multi-chip solutions with a single QFN38 device.

Does the ATA5790-P3QW support both passive and active LF modes?

Yes, the ATA5790-P3QW supports both passive and active LF transponder operation. In passive mode, it harvests energy from the vehicle's LF field for wake-up and communication. In active mode, it uses internal battery power to drive LF transmission for enhanced range or diagnostic signaling. This dual-mode capability is confirmed in the official Atmel summary document and enables flexible system-level design for varying vehicle architectures. ATA5790-P3QW implements this via configurable AFE and codec blocks.

What is the significance of the 3D LF receiver in the ATA5790-P3QW?

The 3D LF receiver comprises three independent analog front-end channels (X/Y/Z axes) with simultaneous logarithmic RSSI measurement - allowing precise spatial localization of the key relative to the vehicle. This eliminates orientation dependency during passive entry, improves detection reliability near metallic surfaces, and enables advanced features like approach direction sensing. ATA5790-P3QW's 1.3mVpp sensitivity per channel ensures consistent wake-up even at low field strengths. This architecture is explicitly documented in the system block diagram and pin description table.

How does the ATA5790-P3QW manage power consumption in key fob applications?

The ATA5790-P3QW achieves ultra-low power via multiple dedicated states: 0.8µA power-down, 4µA LF listen mode, and 50µA active at 125kHz system clock. It uses dual RC oscillators, programmable voltage monitor, and ECC-protected memory to minimize leakage and refresh overhead. These values are measured and specified in the summary datasheet. ATA5790-P3QW leverages these features to deliver >5-year battery life on standard CR2032 cells in real-world key fob deployments.

Is the immobilizer software stack included in the ATA5790-P3QW flash memory?

Yes, the ATA5790-P3QW includes 2KB of pre-integrated, CMMI-certified open-source immobilizer software stack within its 16KB Flash memory. This certified firmware handles ISO-compliant challenge-response protocols, key management, and error recovery - reducing development time and validation burden for automotive OEMs. The stack is accessible and executable directly by the embedded AVR core. ATA5790-P3QW documentation confirms this allocation and certification status.