A4413: Adjustable Frequency Buck or Buck-Boost Pre-Regulator with Synchronous Buck, 5 V Protected LDO, Pulse-Width Window Watchdog, and NPOR


The A4413 is a power management IC that can be configured as a buck or buck-boost pre-regulator to efficiently convert automotive battery voltages into a tightly regulated intermediate voltage complete with control, diagnostics, and protections. The output of the pre-regulator supplies both a 5 V, 75 mAMAX high-voltage protected LDO for remote sensors (V5P), and a 0.8 to 3.3 V, 800 mAMAX adjustable synchronous buck regulator (ADJ). Designed to supply microprocessor power supplies in high-temperature environments, the A4413 is ideal for under hood and other automotive applications.

The A4413 can be enabled by its logic-level (ENB) or highvoltage (ENBAT) input. Diagnostic outputs from the A4413 include a power-on-reset output (NPOR) with a 2 ms rising delay to monitor the synchronous buck, a PowerOK output to monitor the 5 V LDO (POK5V), and an ENBAT status output (ENBATS). Dual bandgaps—one for regulation and one for fault detection—improve long-term reliability of the A4413.

The A4413 contains a pulse-width window watchdog (PWWD) timer that can be programmed to detect pulse widths from 1 to 2 ms (WDADJ). The watchdog timer has an activation delay that scales with the pulse-width setting to accommodate processor startup. The tolerance of the watchdog’s window can be set to ±8%, ±13%, or ±18% using the WDTOL pin. The watchdog timer has an active-low enable pin (WDENn) to facilitate initial factory programming or field reflash programming.

Protection features include under- and overvoltage lockout on both output supply rails. In case of a shorted output, the V5P LDO features foldback overcurrent protection. In addition, the V5P output is protected from a short-to-battery event. Both switching regulators include pulse-by-pulse current limit, hiccup mode short-circuit protection, LX short-circuit protection, missing asynchronous diode protection (VREG only), and thermal shutdown (TSD).

The A4413 is supplied in a low-profile 32-lead, 5 mm × 5 mm, 0.5 mm pitch QFN package (suffix “ET”) with exposed thermal pad.

Top Features

  • Automotive AEC-Q100 qualified
  • 3.5 to 36 VIN operating range, 40 VIN maximum
  • Buck or buck-boost pre-regulator (VREG)
  • Adjustable PWM switching frequency: 250 kHz to 2.4 MHz
  • PWM frequency can be synchronized to external clock
  • Synchronous buck regulator (ADJ) delivers 0.8 to 3.3 V
  • 5 V internal LDO for remote sensors with foldback shortcircuit and short-to-battery protections (V5P)
  • Programmable pulse-width window watchdog (PWWD) with scalable activation delay and selectable tolerance
  • Internal watchdog clock with ±5% accuracy
  • Accepts external WD clock for extreme accuracy
  • Active-low Watchdog Enable pin (WDENn)
  • Dual bandgaps for increased reliability: BGVREF, BGFAULT
  • Power-on reset (NPOR) with rising delay of 2 ms monitors the synchronous buck output
  • PowerOK output monitors the 5 V LDO (POK5V)
  • Logic-enable input for microprocessor control (ENB)
  • High-voltage ignition enable input (ENBAT)
  • ENBAT status indicator output (ENBATS)
  • SLEW rate control helps reduce EMI/EMC
  • Frequency dithering helps reduce EMI/EMC
  • OV and UV protection for both output supply rails
  • Pin-to-pin and pin-to-ground tolerant at every pin
  • −40°C to 150°C junction temperature range
  • Thermal shutdown protection



  • Electronic power steering (EPS) modules
  • Automotive power trains
  • CAN power supplies
  • High-temperature applications

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check Stock
APEK4413KET-01-MH DEMO BOARD -40°C to 125°C No -- Contact your
local sales rep
Distributor Stock
A4413KETTR-J 32-lead QFN -40°C to 135°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.


A4413 Packages

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