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.1.4 Overview of the Fault and Protection Schemes

Table 4-1 Fault and Protection Schemes

FAULT NAME	STATUS BIT	CONDITION	TRIGGER FAULT INTERRUPT	ENTER FAULT RECOVERY	ACTION
V_IN undervoltage	VINUVLO_STATUS	UVLO voltage falls below 0.787 V.	Yes	Yes	Device goes to standby and then attempts to restart once the input voltage rises above threshold.
V_IN overvoltage	VINOVP_STATUS	V_IN voltage rises above 43 V	Yes	Yes	Device goes to standby and waits until input voltage falls below threshold before restarting.
V_DD undervoltage	VDDUVLO_STATUS	V_DD level falls below VDDUVLO threshold.	Yes	No	Device restarts once VDD level rises above VDDUVLO threshold.
V_IN overcurrent	VINOCP_STATUS	Voltage across R_ISENSE exceeds 220 mV	Yes	Yes	Device goes to standby and then attempts to restart 100 ms after fault occurs.
Charge pump fault	CP_STATUS	Charge pump voltage level is abnormal.	Yes	Yes	Device goes to standby and then attempts to restart 100 ms after fault occurs.
Charge pump components missing	CPCAP_STATUS	Charge pump is missing components.	Yes	No	Charge pump is disabled. Charge pump fault will be reported. Device tries to keep normal operation
Boost sync clock invalid fault	BSTSYNC_STATUS	Device is enabled while a valid external SYNC clock is running. Then SYNC stops or changes to frequency <75kHz	Yes	No	Defaults to internal clock frequency selected by BST_FSET resistor. If BST_SYNC input is held high then spread spectrum is enabled. If BST_SYNC input is held low then spread spectrum is disabled
CRC error	CRCERR_STATUS	Factory default configuration for registers, options and trim bits are not corrected loaded from memory	Yes	No	Device functions normally, if possible.
Boost OVP low	BSTOVPLOW_STATUS	FB pin voltage rises above V_{FB_OVPL} level	No	No	Boost stops switching until boost voltage level falls. The device remains in normal mode with LED drivers operational.
Boost OVP high	BSTOVPH_STATUS	FB pin voltage rises above V_{FB_OVPH} level or DISCHARGE pin voltage rises above V_{BST_OVPH}	Yes	Yes	Device goes to standby and waits until output voltage falls below threshold before restarting.
Boost overcurrent	BSTOCP_STATUS	FB pin voltages falls below V_UVP level for 110 ms	Yes	Yes	Device goes to standby and then attempts to start 100 ms after fault occurs.
LEDSET detection fault	LEDSET_STATUS	LEDSET resistor missing or invalid	No	No	Defaults to -channel / mA configuration
MODE detection fault	MODESEL_STATUS	MODE resistor missing or invalid	No	No	Defaults to phase-shift PWM mode, I2C address is
FSET detection fault	FSET_STATUS	BST_FSET or PWM_FSET resistor are missing or an invalid value	No	No	Device keeps operating at 400kHz switching frequency for boost converter and 305Hz for PWM dimming frequency.
ISET resistor fault	ISET_STATUS	ISET pin voltage is pulled down to below 1V due to ISET pin resistor shorted to GND	Yes	No	LED_CURRENT[11:0] is written to 0x3FF. Total LED current limited to 65mA.
Thermal shutdown	TSD_STATUS	Junction temperature rises above T_SD threshold.	Yes	Yes	Device goes to standby and then attempts to restart once die temperature falls below threshold.
Open LED string	LED_STATUS OPEN_LED	Headroom voltage on one or more channels is below minimum level and boost has adapted to maximum level.	Yes	No	Faulted LED string is disabled and removed from adaptive boost control loop. String is re-enabled next power cycle.
LED internal short	LED_STATUS_SHORT_LED	Headroom voltage on one or more channels is above the SHORTED_LED_THRESHOLD for > 5 ms while the headroom of at least one channel is still below this threshold.	Yes	No	Faulted LED string is disabled and removed from adaptive boost control loop. String is re-enabled next power cycle.
LED short to GND	LED_STATUS_GND_LED	During PL FET SOFT START, voltage of one or more used LED output is below V_HEADROOM when small test current is injected. In BOOST_SU and Normal Stage, voltage of one or more used LED output is below V_SHORTGND.and keeps still when the corresponding channel is off and small test current is injected	Yes	Yes	Device goes to standby and then attempts to restart 100 ms after fault occurs.
Invalid LED string detected	INVSTRING_STATUS	Configured unused LED output is detected not short to GND.	Yes	No	Device functions normally, if possible.
I2C timeout	I2C_ERROR_STATUS	Device receives I2C command without STOP signal for 500 ms	Yes	No	Device functions normally and waits for the next I2C command.