Solar Micro Inverter Solutions

The AFE031 is a low-cost, integrated, powerline communications (PLC) analog front-end (AFE) device that is capable of capacitive- or transformer-coupled connections to the powerline while under the control of a DSP or microcontroller. It is ideal for driving low-impedance lines that require up to 1.5 A into reactive loads. The integrated receiver is able to detect signals down to 20 µVRMS and is capable of a wide range of gain options to adapt to varying inputsignal conditions. This monolithic integrated circuit provides high reliability in demanding powerline communications applications.

The AFE031 transmit power amplifier operates from a single supply in the range of 7 V to 24 V. At maximum output current, a wide output swing provides a 12-VPP (IOUT = 1.5 A) capability with a nominal 15-V supply. The analog and digital signal processing circuitry operates from a single 3.3-V power supply.

The AFE031 is internally protected against overtemperature and short-circuit conditions. It also provides an adjustable current limit. An interrupt output is provided that indicates both current limit and thermal limit. There is also a shutdown pin that can be used to quickly put the device into its lowest power state. Through the four-wire serial peripheral interface, or SPI™, each functional block can be enabled or disabled to optimize power dissipation.

The AFE031 is housed in a thermally-enhanced, surface-mount PowerPAD package (QFN-48). Operation is specified over the extended industrial junction temperature range of –40°C to +125°C.

The SM72295 is designed to drive 4 discrete N type MOSFET’s in a full bridge configuration. The drivers provide 3A of peak current for fast efficient switching and integrated high speed bootstrap diodes. Current sensing is provided by 2 transconductance amplifiers with externally programmable gain and filtering to remove ripple current to provide average current information to the control circuit. The current sense amplifiers have buffered outputs available to provide a low impedance interface to an A/D converter if needed. An externally programmable input over voltage comparator is also included to shutdown all outputs. Under voltage lockout with a PGOOD indicator prevents the drivers from operating if VCC is too low.