AC7840-PMIC
ASIL-D capable multi-channel PMIC with voltage monitoring and safety features for automotive safety systems
Product Overview
Description
The AC7840-PMIC is a multi-channel power management IC designed for safety-critical automotive applications.
With triple output regulators, voltage monitoring, and ASIL-D safety features, it is ideal for powering safety-critical MCUs.
The device includes window watchdog, safety monitoring outputs, and comprehensive diagnostic capabilities.
Product Series
AC
Primary Application
Safety-critical ECU power
Key Features
- Triple output voltage regulators
- Independent voltage monitoring
- Window watchdog with programmable timeout
- ASIL-D functional safety support
- Safety monitoring output pins
- Diagnostic SPI interface
- Independent voltage reference for ADC
- AEC-Q100 Grade 1 qualified
Specifications
| Input Voltage | 3.5V to 40V |
|---|---|
| Output Channels | 3 (1x MCU core, 1x I/O, 1x ADC reference) |
| Output Current | 1A total (configurable) |
| Voltage Monitoring | Window watchdog with 1% accuracy |
| Safety Features | ASIL-D support, independent monitoring |
| Package | TSSOP-20, QFN-32 |
Applications
Safety-critical ECU power
Electronic system design
ASIL-D MCU power supply
Power conversion and supply
ADAS system power
Automotive and EV electronics
Braking system control
Industrial automation and control
Steering system control
Industrial automation and control
FAE Expert Insights
"The AC7840-PMIC is my recommended solution for safety-critical automotive applications requiring ASIL compliance. The triple output architecture with separate core, I/O, and ADC reference supplies provides clean power distribution for safety MCUs. I have successfully used this PMIC in electric power steering and braking control modules. The independent voltage monitoring with window watchdog is essential for ASIL-D compliance, providing fault detection independent of the main MCU. The safety monitoring outputs allow direct connection to safety logic for fast fault response. The diagnostic SPI interface provides detailed fault information for system diagnostics. For safety-critical applications, this PMIC offers excellent value compared to international safety PMIC suppliers."
ASIL-D safety PMIC with comprehensive monitoring for safety-critical automotive systems
— Jennifer Liu, BeiLuo
Frequently Asked Questions
What safety features does AC7840-PMIC include?
The AC7840-PMIC includes comprehensive safety features for ASIL-D compliance. Key features include independent voltage monitoring for all three output channels with 1% accuracy, window watchdog with programmable timeout periods, safety monitoring output pins for direct safety logic interface, and diagnostic SPI interface for detailed fault reporting. The PMIC also includes internal self-testing capabilities and fault injection support for safety system validation.
AC7840-PMIC provides complete ASIL-D safety monitoring for safety-critical automotive applications.
How does the window watchdog work?
The AC7840-PMIC window watchdog monitors the connected MCU's operation by requiring periodic service within a defined time window. If the MCU fails to service the watchdog within the window (too early or too late), the PMIC detects a fault and can trigger system reset or safety state. The window boundaries are programmable via SPI, allowing configuration for different MCU response time requirements. This window watchdog provides more robust fault detection than simple timeout watchdogs.
Window watchdog provides superior fault detection compared to simple timeout watchdogs.
What is the voltage monitoring accuracy?
The AC7840-PMIC provides voltage monitoring accuracy of 1% over temperature and supply variations. Each output channel is monitored independently with programmable under-voltage and over-voltage thresholds. The monitoring circuits are independent of the voltage regulators to ensure fault detection even if a regulator fails. The 1% accuracy ensures reliable detection of voltage deviations that could affect MCU operation.
1% monitoring accuracy ensures reliable detection of voltage faults affecting safety systems.
Can AC7840-PMIC be used with non-AutoChips MCUs?
Yes, the AC7840-PMIC can be used with any automotive MCU requiring safety power management. The output voltages are configurable to support various MCU requirements (3.3V or 5V I/O, 1.2V or 1.3V core). The watchdog interface uses standard digital signals compatible with any MCU GPIO. The SPI diagnostic interface follows standard SPI protocol for easy integration. However, using with AutoChips AC7840x MCUs provides optimized integration and complete safety documentation.
AC7840-PMIC works with any MCU, but optimized integration with AutoChips MCUs.
What diagnostic information is available via SPI?
The AC7840-PMIC provides comprehensive diagnostic information via SPI interface including voltage monitoring status for all channels (normal, under-voltage, over-voltage), watchdog service status and fault history, thermal status and overtemperature warnings, and internal self-test results. The diagnostic data can be read by the MCU for system health monitoring and fault logging. The SPI interface also allows configuration of voltage thresholds and watchdog timing.
Comprehensive SPI diagnostics enable predictive maintenance and fault analysis.