Evaluate improvements

Blog post: 2023-12-02-pcba-analyses

VBS

How could this design be simplified?

Good question. There are a few ways this vehicle display system design could potentially be simplified:

Processor/Peripherals Integration

• A more integrated system-on-chip with display driver, graphics, connectivity could reduce component count.

Eliminate Separate LCD Backlight Driver

• Integrate backlight control into the display panel or main processor using PWM.

Reduce Memory Redundancy

• Remove duplicate RAM/flash chips and focus on reliability through software redundancy.

Shared Regulators

• Use a multicore PMIC to combine similar power rails reducing regulation overhead.

Functional Decomposition

• Break out high voltage elements like LCD panel supplies into separate board for isolation.

Connector Consolidation

• Standardize more around a few connector groupings by communication type to minimize unique cables.

Streamline Interfaces

• Support more functions through fewer shared digital buses instead (e.g. SPI, I2C).

However, simplification may undermine customizability, reliability and long term stability crucial in vehicles. There are always tradeoffs to evaluate! Please let me know if any other specific simplification approaches come to mind.

If I was to update this design using today’s parts what improvements should I consider making?

Here are some potential improvements to consider in updating this vehicle display system design using today’s modern components:

• Processor Upgrade - Move to a faster Cortex-M7 or multicore processor architecture to support more advanced graphics, computer vision, and connectivity needs.
• Display Panel - Switch to a higher resolution TFT panel with capacitive multi-touch support and improved brightness, contrast, and efficiency.
• Memory - Increase RAM and flash capacity to support more dashboard info, data logging, reconfigurable displays, over-the-air updates, etc.
• Connectivity - Add Bluetooth and WiFi connectivity for diagnostics, mobile integration, navigation and enriched cluster experiences.
• Sensors - Incorporate additional environmental sensors, cameras, object detection, driver monitoring systems to feed back into the cluster.
• HMI Upgrades - Enhanced and reconfigurable digital cluster layouts; haptic, audible user feedback; head-up displays.
• Functional Safety - Implement ASIL-rated processors, additional monitoring controllers, redundancy, and fault protections for safety critical applications.
• Power Reduction - Improve regulators’ efficiency; integrate PMIC; utilize lower power components; optimize for low power modes.
• Cybersecurity - Hardware security modules, secure bootloaders, cryptography blocks to protect against risks from connected systems.

The overall focus would be on leveraging today’s exponentially more powerful and efficient processors, displays, sensors and connectivity options to greatly enrich the driver/passenger experience while maintaining safety, security and reliability. Lots of room for innovation!

BMS

Suggest cost reductions

How could this design be modified to reduce cost?

Here are some suggestions to reduce the cost of this battery monitor PCB design:

1. Switch to a 4 layer PCB from 6 layers. Dropping to 4 layers greatly reduces fabrication costs, though it could require some design tweaking.
2. Replace some of higher pin count ICs with smaller packages:
3. Microcontroller: Switch to a QFN/QFP package from TQFP
4. Op amps: SOIC8 package instead of SOIC14
5. Digital isolator: Smaller DFN instead of SOIC8
6. Reduce number of voltage monitors (BQ29410) from 3 ICs to 2 ICs if acceptable voltage measurement resolution is available.
7. Use a 2 or 3 channel SPI ADC instead of microcontroller integrated ADC and quad op amps. A simple micropower delta-sigma ADC with SPI interface costs less than quad op amp + high pin count micro.
8. Check if number of fuse positions for overvoltage protection can be reduced. But don’t compromise safety.
9. Review if all connector options are needed. Eliminate extra connectors not essential to operation.
10. Double check the necessity of the conformal coating requirement as it likely adds significant cost.

Potential impact of these changes could reduce cost by 25-40%+. Drawbacks could be higher design/validation effort needed, less monitoring precision or resolution available. Overall the design seems quite optimized already from a cost standpoint.

Let me know if you have any other questions!