Back to Allegro MicroSystems

Allegro MicroSystems A81805/A81805-1 Synchronous Buck Regulators

Allegro MicroSystems A81805/A81805-1 Synchronous Buck Regulators are 40V synchronous buck regulators with low EMI and 6µA quiescent current that allows high efficiency over a full load of up to 2.5A. The A81805/A81805-1 regulators support a unique architecture that reduces the amount of EMI generated by the switching components to minimize the number of external components.

The very low 6uA quiescent current of the Allegro MicroSystems A81805/A81805-1 Synchronous Buck Regulators facilitates maximized battery life in standby mode. The device's wide input voltage range encapsulates many transients in automotive and industrial applications and remains on as the voltage drops.

Features

  • AEC-Q100 Grade 0 qualified
  • VIN Range of 3.5V to 36V operating, 40V transient
  • VOUT of 3.3V, ±1.5% accuracy, ‒40°C to 150°C (5V for the A81805-1)
  • Up to 2.5A of continuous output current
  • 92%, 12V input to 5V output, 1A, 2MHz High efficiency
  • Integrated compensation eliminates three external components
  • Low-Power (LP) mode of 6µA IQ from VIN at no load, an automatic transition from LP to PWM mode
  • Fixed-Frequency PWM (fOSC) of 400kHz to 2.5MHz programmable
  • Synchronizable switching frequency (400kHz to 2.5MHz) is PLL-based, fSYNC can be above or below fOSC
  • Spread spectrum applied helps to pass CISPR25 class 5
  • Internally set soft-start
  • Accurate ENABLE input threshold
  • Open-drain PGOOD output with delay
  • Pre-bias startup capable
  • Maximized duty cycle at low VIN improves dropout
  • Overvoltage, pulse-by-pulse current limit, hiccup mode short-circuit, and thermal protection
  • Robust FMEA of pin open/short and component faults

Applications

  • Infotainment
  • Battery-powered systems
  • Industrial systems
  • Container tracking
  • Handheld instruments
  • Audio systems
  • ADAS
    • Instrument clusters
    • Power steering
    • Radar

Associated Products

Allegro MicroSystems Single Output Regulators

Robust, efficient, fault-protecting regulator solutions that minimize power loss.

Learn Moreabout Allegro MicroSystems Single Output Regulators View Productsrelated to Allegro MicroSystems Single Output Regulators

Typical Application Diagram

Application Circuit Diagram - Allegro MicroSystems A81805/A81805-1 Synchronous Buck Regulators

Block Diagram

Block Diagram - Allegro MicroSystems A81805/A81805-1 Synchronous Buck Regulators

Evaluation Kit

Allegro MicroSystems A81805 Evaluation Kit

Used to evaluate the A81805 Synchronous Buck Regulator.

Learn Moreabout Allegro MicroSystems A81805 Evaluation Kit View Productsrelated to Allegro MicroSystems A81805 Evaluation Kit

Clean Energy

Allegro MicroSystems Clean Energy

A solution to advance technology for a safer, more sustainable future.

Learn Moreabout Allegro MicroSystems Clean Energy View Productsrelated to Allegro MicroSystems Clean Energy
Published: 2022-07-18 | Updated: 2023-12-13