A4411: Adjustable Frequency Buck or Buck/Boost Pre-Regulator with a Synchronous Buck, 3 LDOs, Pulse-Width Window Watchdog, NPOR, and POK5V

The A4411 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 a 5 V/150 mAMAX LDO for “local” sensors (V5SNR), a 5 V / 200 mAMAX LDO for communications (V5CAN), a 5 V / 120 mAMAX tracking/ protected LDO for remote sensors (V5P), and a 0.8 to 3.3 V / 800 mAMAX adjustable synchronous buck regulator (ADJ). Designed to supply CAN or microprocessor power supplies in high-temperature environments, the A4411 is ideal for underhood applications.

The A4411 can be enabled by its logic level (ENB) or highvoltage (ENBAT) input. The A4411 includes a TRACK pin to set the reference of the V5P tracking regulator to either V5SNR or the buck FBADJ pin, so the A4411 can be adapted across multiple platforms with different sensors and supply rails. Diagnostic outputs from the A4411 include a power-on-reset output (NPOR) with a fixed delay, an ENBAT status output, and a Power OK output for the 5 V LDOs (POK5V). Dual bandgaps, one for regulation and one for fault checking, improve long-term reliability of the A4411.

The A4411 contains a Pulse-Width Window Watchdog (PWWD) that can be programmed to detect pulse widths from 1 to 2 ms (WDADJ). The watchdog 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 has an active-low enable pin (WDENn) to facilitate initial factory programming or field reflash programming.

Protection features include under- and overvoltage lockout on all four CPU supply rails. In case of a shorted output, all linear regulators feature 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.

The A4411 is supplied in a low-profile 38-lead eTSSOP package (suffix “LV”) with exposed power pad.

ASIL LogoAllegro's A4411 is a Quality Managed (QM) product that has been developed according to the automotive quality requirements of TS 16949 and contains features targeted for automotive safety applications. This product can be qualified for use in accordance with ISO 26262 in compliant safety systems by ensuring a robust integration of the component into the system design. Safety documentation will be provided to support and guide the integration process.



  • Electronic Power Steering (EPS) Modules
  • Automotive Power Trains
  • CAN Power Supplies
  • High-temperature applications

Astrorep Inc. (Allegro and Sanken Semiconductors, Sanken Power Supplies)
700 Veterans Memorial Hwy
Suite 310
Hauppauge, NY 11788
Phone: (631)422-2500
Fax: (631)422-2504
Web: www.astrorepinc.com
Email: donna.tweedy@astrorepinc.com

If this is not your local representative, find your local sales rep here.

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  • 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
  • Two 5 V LDOs for “local” sensors (V5SNR) and communications (V5CAN) with foldback short-circuit protections
  • 5 V internal tracking LDO for remote sensors with fold back short circuit and short-to-battery protections (V5P)
  • TRACK sets FBADJ or V5SNR as the reference for V5P
  • Programmable pulse-width window watchdog (PWWD) with scalable activation delay and selectable tolerance
  • Internal Watchdog (WD) CLK with ±5% accuracy
  • Accepts external WD CLK for improving accuracy
  • Active-Low Watchdog Enable pin (WDENn)
  • Dual bandgaps for increased reliability: BGVREF, BGFAULT
  • Power-on reset (NPOR) with fixed delay of 2 ms
  • Power OK output for 5 V LDOs UV/OV (POK5V)
  • Logic enable input for microprocessor control (ENB)
  • High-voltage ignition enable input (ENBAT)
  • ENBAT status indicator output (ENBATS)
  • SLEW rate control pin helps reduce EMI/EMC
  • Frequency dithering helps reduce EMI/EMC
  • OV and UV protection for all four CPU supply rails
  • Pin-to-pin and pin-to-ground tolerant at every pin
  • Thermal shutdown protection
  • -40°C to 150°C junction temperature range

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Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check
Distributor Stock
APEK4411KLV-01-MH DEMO BOARD -20°C to 85°C No -- Contact your
local sales rep
Check Stock
A4411KLVTR-T 38-lead TSSOP -40°C to 135°C Yes View Data Contact your
local sales rep
Check 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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