A8584: Wide Input Voltage, 500 kHz , 2.5 A Asynchronous Buck Regulator


The A8584 is an adjustable frequency, high output current, PWM regulator that integrates a low resistance, high-side, N-channel MOSFET. The A8584 incorporates current-mode control to provide simple compensation, excellent loop stability, and fast transient response. The A8584 utilizes external compensation to accommodate a wide range of power components to optimize transient response without sacrificing stability.

The A8584 regulates input voltages from 4.7 to 36 V, down to output voltages as low as 0.8 V, and is able to supply approximately 2.5 A of load current. The A8584 features include an externally adjustable switching frequency, an externally set soft start time to minimize inrush currents, an EN/SYNC input to either enable VOUT and/or synchronize the PWM switching frequency, and a Power OK (POK) output to indicate when VOUT is within regulation. The A8584 only turns on the lower FET to charge the boot capacitor when needed, not at every PWM cycle. This improves light load efficiency and provides no-load currents low. The sleep mode current of the A8584 control circuitry is less than 3 μA.

Protection features include VIN undervoltage lockout (UVLO), pulse-by-pulse overcurrent protection (OCP), hiccup mode short-circuit protection (HIC), and thermal shutdown (TSD). In addition, the A8584 provides adjacent pin short-circuit and short-to-ground protection at every pin to satisfy the most demanding applications.

The A8584 device is available in a 16-pin TSSOP package with exposed pad for enhanced thermal dissipation. It is lead (Pb) free, with 100% matte tin leadframe plating.

Top Features

  • Automotive AEC-Q100 qualified
  • Wide operating voltage range: 4.7 to 36 V
  • UVLO stop threshold is at 3.8 V (typ)
  • Supports 40 V input for surge and load dump testing
  • Adjustable output voltage as low as 0.8 V
  • Internal 800 mV reference with ±1.5% accuracy
  • Internal 100 mΩ high-side switching MOSFET
  • Adjustable switching frequency, fSW: 250 to 500 kHz
  • Synchronization to external clock: 1.2 × fSW to 1.5 × fSW
  • Sleep mode supply current less then 3 μA
  • Soft start time externally set via the SS pin
  • Very low no-load current
  • Pre-bias startup compatible
  • Power OK (POK) output
  • Pulse-by-pulse current limiting (OCP)
  • Hiccup mode short-circuit protection (HIC)
  • Overtemperature protection (TSD)
  • Open-circuit and adjacent pin short-circuit tolerant
  • Short-to-ground tolerant at every pin
  • Externally adjustable compensation
  • Stable with ceramic output capacitors

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check Stock
APEK8584KLP-33-MH DEMO BOARD -20°C to 85°C No -- Contact your
local sales rep
Distributor Stock
APEK8584KLP-50-MH DEMO BOARD -20°C to 85°C No -- Contact your
local sales rep
Distributor Stock
A8584KLPTR-T 16-lead TSSOP -40°C to 125°C Yes View Data Contact your
local sales rep
Distributor Stock

Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm.



Design Support Tools