A8650: Low Input Voltage, Adjustable Frequency 2 A Synchronous Buck Regulator with EN/SYNC and Power OK


The A8650 is an adjustable frequency, high output current, PWM regulator that integrates a high-side, P-channel MOSFET and a low-side, N-channel MOSFET. The A8650 incorporates current-mode control to provide simple compensation, excellent loop stability, and fast transient response. The A8650 utilizes external compensation to accommodate a wide range of power components to optimize transient response without sacrificing stability. The A8650 regulates input voltages from 2.5 to 5.5 V, down to output voltages as low as 0.8 V, and is able to supply at least 2.0 A of load current.

A8650 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 sleep mode current of the A8650 control circuitry is less than 3 μA. Protection features include VIN undervoltage lockout (UVLO), cycle-by-cycle overcurrent protection (OCP), hiccup mode short circuit protection (HIC), overvoltage protection (OVP), and thermal shutdown (TSD). In addition, the A8650 provides open circuit, adjacent pin short circuit, and short to ground protection at every pin to satisfy the most demanding automotive applications.

The A8650 is available in both 10-pin MSOP and DFN packages with an exposed pad for enhanced thermal dissipation. It is lead (Pb) free, with 100% matte tin leadframe plating.


  • GPS/Infotainment
  • Automobile Audio
  • Home Audio
  • Network and Telecom

Top Features

  • Automotive AEC-Q100 qualified
  • Operating voltage range: 2.5 to 5.5 V
  • UVLO stop threshold: 2.25 V (max)
  • Adjustable switching frequency (fOSC): 0.25 to 2.45 MHz
  • Synchronizes to external clock: 1.2× to 1.5× fOSC (typ)
  • Internal 70 mΩ high-side switching MOSFET
  • Internal 55 mΩ low-side switching MOSFET
  • Capable of at least 2.0 A steady-state output current
  • Sleep mode supply current less than 3 μA
  • Adjustable output voltage as low as 0.8 V with ±1% accuracy from –40°C to 125°C
  • Soft start time externally set via the SS pin
  • Pre-biased startup capable
  • Externally adjustable compensation
  • Stable with ceramic output capacitors
  • Enable input, and Power OK (POK) output
  • Cycle-by-cycle current limiting (OCP)
  • Hiccup mode short circuit protection (HIC)
  • Overvoltage protection (OVP)
  • Overtemperature protection (TSD)
  • Open circuit and adjacent pin short circuit tolerant
  • Short to ground tolerant at every pin

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check Stock
A8650KEJTR-T 10-lead DFN -40°C to 125°C Yes View Data Contact your
local sales rep
Distributor Stock
A8650KLYTR-T 10-lead MSOP -40°C to 125°C Yes View Data Contact your
local sales rep
Distributor Stock
APEK8650KEJ-01-MH DEMO BOARD -40°C to 125°C No -- Contact your
local sales rep
Distributor Stock
APEK8650KLY-01-MH DEMO BOARD -40°C to 125°C No -- 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.



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