STMicroelectronics A7987 automotive switching regulator

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The STMicroelectronics A7987 automotive switching regulator has a wide input-voltage range that allows use in trucks and buses, and an adjustable output voltage that ensures flexibility and stable performance to power the numerous voltage rails in automotive applications such as body infotainment and telematics.

With maximum input voltage of 61 V, the product can operate from a 24 V battery in a conventional or hybrid/electric vehicle and maintain a regulated output despite disturbances such as load-dump. The output is adjustable from 0.8 V up to the input voltage, with low dropout, and can provide up to 3 A for a wide variety of loads from logic to lighting.

The current limit and switching frequencies up to 1.5 MHz are set with external pulldown resistors, letting designers create compact power modules by optimising the output-inductor size. Pulse-by-pulse current sensing with digital frequency foldback in short circuit minimises stress on power components. Thermal protection is built in, with shutdown and auto-recovery to minimise reliance on external intervention.

The device embeds a low-resistance N-channel power MOSFET. At light load, pulse skipping maintains output regulation and a bias-voltage input with integrated switchover allows powering analog circuitry from an external source for optimum efficiency.

A synchronisation pin allows up to five regulators to co-exist by switching out of phase to avoid noise effects and reduce the RMS current flowing in the input capacitor. An Enable pin and a Power-Good indicator with adjustable delay permit power-up sequencing. There is also an adjustable soft-start function to limit inrush current.

For more information: www.st.com/a7987-pr.