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, VIN 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
VOUT reaches regulation, and it goes low when VOUT 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.
