米6体育平台手机版

SNVA966 July 2020 – MONTH LP8864-Q1 , LP8864S-Q1 , LP8866-Q1 , LP8866S-Q1

Trademarks
1Fault Handling Routine
2Different Fault and Diagnostic Handling Method Recommendation
1. 2.1 Different Fault Handling Method
2. 2.2 Different Diagnostic Wrong Information Handling Method
  1. 2.2.1 System-Level Critical Wrong Diagnostic Information
  2. 2.2.2 System Level Sustainable Wrong Diagnostic Information
3Summary
A Fault-Related Functions
1. A.1 Protection and Fault Detections
  1. A.1.1 Supply Faults
    1. A.1.1.1 VIN Undervoltage Faults (VINUVLO)
    2. 16
    3. A.1.1.2 VIN Overvoltage Faults (VINOVP)
    4. A.1.1.3 VDD Undervoltage Faults (VDDUVLO)
    5. A.1.1.4 VIN OCP Faults (VINOCP)
    6. A.1.1.5 Charge Pump Faults (CPCAP, CP)
    7. A.1.1.6 Boost Sync Clock Invalid Faults (BSTSYNC)
    8. A.1.1.7 CRC Error Faults (CRCERR)
  2. A.1.2 Boost Faults
  3. A.1.3 LED Faults
    1. A.1.3.1 Open LED Faults (OPEN_LED)
    2. A.1.3.2 Short LED Faults (SHORT_LED)
    3. A.1.3.3 LED Short to GND Faults (GND_LED)
    4. A.1.3.4 Invalid LED String Faults (INVSTRING)
    5. A.1.3.5 I2C Timeout Faults
  4. A.1.4 Overview of the Fault and Protection Schemes
2. A.2 Programming Examples
  1. A.2.1 Clearing Fault Interrupts
  2. A.2.2 Disabling Fault Interrupts
  3. A.2.3 Diagnostic Registers

A.1.3.2 Short LED Faults (SHORT_LED)

Short LED fault is detected if one or more LED outputs are above the V_LEDSHORT typical 6 V and at least one LED output is inside the normal operation window (see Figure 4-3). Shorted string is disconnected from the boost adaptive control loop and the LED PWM output is disabled. LED_STATUS status bit is set and an interrupt generated similarly as in open LED case. Detailed shorted LED fault can be read from bits SHORT_LED and LEDx_FAULT (x = 1...4 (LP8864-Q1 & LP8864S-Q1)/ 6 (LP8866-Q1 & LP8866S-Q1)), indicating the faulty LED) in LED_FAULT_STATUS register.

In HUD application, when output channels are connected as groups and only one or two groups are active, one more special condition will trigger the short LED fault. This is when boost adaptive voltage comes to minimum and one of the LED channels voltage is still higher than V_HEADROOM + V_{HEADROOM_HYS}.