A8587: Wide Input Voltage, Adjustable Frequency, 2 Amp Non-Synchronous Buck Regulator with Enable and NPOR

The A8587 is a high-frequency step-down switching regulator with an integrated high-side power MOSFET. It provides up to 2 A output current. The A8587 can achieve fast transient response using current-mode control and simple external compensation.

The wide input range of 3.8 to 36 V makes the A8587 suitable for a wide range of step-down applications, including those in an automotive input environment. Battery-driven applications benefit from the low 30 μA operational quiescent current. The A8587 maintains high efficiency across a wide load range by the use of pulse-frequency modulation (PFM) as the load reduces. This in turn reduces switching and gate driver losses at light load.

Frequency foldback helps to prevent inductor current runaway during startup and provides enhanced dropout performance. Extensive protection features of the A8587 include pulse-by-pulse current limit, hiccup-mode short-circuit protection, open/short freewheeling diode protection, BOOT open/short voltage protection, V_IN undervoltage lockout, and thermal shutdown. The A8587 also provides an active-low power-on reset (NPOR) signal. This signal goes high—after a short delay—when V_OUT reaches regulation, and it goes low when V_OUT falls out of regulation.

The A8587 is designed to aid in EMC/EMI design by including frequency dithering, soft freewheel diode turnoff, and wellcontrolled switch-node slew rates. A 4 MHz oscillator allows the A8587 to switch outside EMI-sensitive frequency bands such as the AM band or ADSL bands.

The A8587 is available in an industry standard DFN10 package.