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


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Top Features


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.

  • 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

Typical Applications

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.

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