AtmelATA5279LF线圈驱动方案

Atmel公司的ATA5279能同时驱动六个单独的低频(LF)天线线圈,具有优异的EMC性能,对负载具有热和电保护,它的SPI接口很容易和微控制器的总线连接,并且具有非常低的关断模式电流,广泛用于汽车电子中.本文介绍了ATA5279的主要性能,方框图以及应用电路.

Atmel Unveils Industrys First Off-the-Shelf LF Antenna Driver IC for Passive Entry Go/Passive Go Systems
The ATA5279 is an LF coil driver IC intended for passive entry/-go (PEG) systems. It
can drive up to six low-frequency-antennas (i.e., coils) to provide a wake-up and initialization channel to the key fob.

Antenna Driver for Multiple Antennas ATA5279
The ATA5279 is capable of sequentially driving up to six separate 125 kHz low-frequency antennas (i.e., coils) to provide a wake-up and initialization channel to the key fob. Superior EMC behavior is guaranteed by the sinusoidal-like output signals at all six channels, which helps avoid interferences with other electronic car components. In addition, the IC has twenty individually selectable coil currents steps at each channel to enable precise field-strength measurements.
With its superior diagnostics, the ATA5279 monitors all six connected antennas and stores any possible failures in the internal register. As a result of this, the ATA5279 protects the system and itself from any damage, reducing service work at the OEMs assembly line and their authorized repair shops.

ATA5279主要特性:
Six Connections for Series-resonant LF Coil Antennas
Drives up to 1A Peak Current on the First Three Channels and up to 700 mA Peak on the Second Three, Largely Independent of the Battery Voltage
• On-off-keyed Data Modulation with up to 6 kbit/s
Sinusoidal-like Output Signal for Superior EMC Behavior
20 Selectable Steps for Current Regulation for Field Strength Measurement (RSSI)
Full Protection Against Overload (Electrical and Thermal)
Very Low Power-down Current Consumption
SPI Interface for Easy Microcontroller Bus Connection
LF Data Buffer to Minimize Microcontroller’s CPU Load During a Data ransmission
Small Outline Package: QFN48, 7 mmX7 mm



图1. ATA5279方框图



图2. ATA5279应用电路

详情请见:
http://www.atmel.com/dyn/resources/prod_documents/doc9125.pdf013