A7987TR

Overview

The A7987TR is a 61 V, 3 A asynchronous step-down switching regulator manufactured by STMicroelectronics. It operates with an input voltage range of 4.5 V to 61 V and provides an adjustable output voltage from 0.8 V to the input voltage. The device features an adjustable switching frequency between 250 kHz and 1.5 MHz, enabling compact design through high-frequency operation. It includes integrated pulse-by-pulse current sensing with digital frequency fold-back for short-circuit protection and supports synchronization via the SYNCH pin. Qualified under AEC-Q100 standards, it is housed in a 16-HTSSOP package.

Feature Summary

• Asynchronous buck topology with embedded high-side power MOSFET delivering up to 3 A DC output current
• Wide input voltage range supporting automotive battery systems with almost 100% duty cycle capability
• Integrated light load management via VBIAS pin switch-over and pulse skipping to maximize efficiency
• Adjustable soft-start, current limitation threshold, and switching frequency for application optimization

Applications

• Automotive system battery-powered applications
• Infotainment systems requiring low noise through synchronized operation
• General DC-DC step-down conversion in automotive electronics

Procurement Notes

Verify the specific ordering suffix (e.g., TR for reel) against the manufacturer's official datasheet to ensure correct packaging configuration. Confirm that the AEC-Q100 qualification status meets your project's reliability requirements. Check the latest datasheet revision for any updates on thermal characteristics or recommended external component values before finalizing the bill of materials.

Selection Notes

Select this component when designing for automotive environments requiring high input voltage tolerance up to 61 V. It is suitable for applications needing adjustable output voltages starting from 0.8 V and flexible switching frequencies to optimize inductor size. Consider the asynchronous nature for cost-sensitive designs where synchronous rectification is not mandatory, and utilize the synchronization feature if multiple converters are used in close proximity to reduce electromagnetic interference.

Part Context

The A7987 belongs to STMicroelectronics' family of wide-voltage automotive switching regulators. It is designed to meet the stringent fail-safe specifications required in automotive systems. The device complements other PMIC solutions by offering robust performance in harsh electrical environments, specifically targeting applications where high input voltage rejection and reliable current delivery are critical.

Replacement Considerations

The L7987 is a related synchronous variant within the same product family. Verify compatibility regarding switching frequency ranges and control pin configurations if substituting between asynchronous and synchronous versions. Ensure that the thermal performance and inductor selection align with the specific converter type selected.