The A8586 is a high frequency step-down switching regulator
with an integrated high-side power MOSFET. It provides up
3.5 A output current. The A8586 can achieve fast transient
response utilizing current mode control and simple external
compensation.
The wide input range of 3.8 V to 36 V makes the A8586 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 A8586 provides 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. A8586-1 and A8586-2 are options
that disable the PFM function. A8586-1 also disables the
dithering feature. These can be useful when low output ripple
and minimum output capacitance is required.
Frequency fold back helps prevent inductor current runaway
during startup and provides enhanced dropout performance.
Extensive protection features of the A8586 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 A8586 and A8586-2 are designed to aid in EMC/EMI
design by including frequency dithering, soft freewheel diode
turn off, and well controlled switch node slew rates. A 4 MHz
oscillator allows the A8586 to switch outside EMI sensitive
frequencies bands such as the AM band or ADSL bands.
The A8586 is available in industry standard DFN10 or SOIC8
packages.
