CCS / LP8860-Q1：Fault pin

matt chen

Prodigy 110 points

Part Number: LP8860-Q1

Tool/software: Code Composer Studio

hello~

i have a question

I set EEPROM 0X86 to 0X6F

Vin = 12V, why Fault pin not high

i read 0x0F=0x40

over 6 years ago

0 matt chen over 6 years ago

Prodigy 110 points

LED current and LED voltage how to use the value of the register?

0 Salome Ramirez Carrion over 6 years ago in reply to matt chen

TI__Intellectual 2180 points

Hi Matt,

Sounds like Fault pin and VIN OVP Fault Flag are working ok. Fault pin is open-drain so should be pulled low when fault event occurs and pulled high for normal operation or after doing a CLEAR fault.

Not sure I understand your last question. Could you be more specific into which registers you are referring to?

Best Regards,

Salome

0 matt chen over 6 years ago in reply to Salome Ramirez Carrion

Prodigy 110 points

Hello~

I want to express , DISP_CL1_BRT and DISP_CL1_CURRENT two registers can be changed
LED brightness
How do I use these two registers to calculate current value and voltage value

0 matt chen over 6 years ago in reply to Salome Ramirez Carrion

Prodigy 110 points

There is any possibility that I will FAULT PULL HIGH
In the failure did not happen to be pulled to LOW

Incidentally, the cause of the LED flicker?

0 Salome Ramirez Carrion over 6 years ago in reply to matt chen

TI__Intellectual 2180 points

Hi Matt,

DISP_CL1_CURRENT[11:0] sets the actual maximum current which can be same or lower than DRV_LED_CURRENT_SCALE[2:0] value, which sets the max scale or maximum current limit.

DISPL_CL1_BRT determines the brightness or duty % if BRIGHTNESS REGISTER is used as the display brightness mode, or it will also affect brightness % if PWM INPUT DUTY x BRIGHTNESS REGISTER mode is used.

Output voltage will be determine by your LED load forward voltage (typ 3V per LED) plus headroom voltage at the output pin ~1-2V.

Best,

Salome

0 matt chen over 6 years ago in reply to Salome Ramirez Carrion

Prodigy 110 points

ok,i have a new question

How setting boost_OVP and boost_OCP THRESHOLD ??

because EEPROM not setting boost_OVP OCP value

0 Salome Ramirez Carrion over 6 years ago in reply to matt chen

TI__Intellectual 2180 points

Hi Matt,

Boost OCP can be limited with BOOST_IMAX_SEL[2:0] register.

Boost OVP is preset condition, no register is available for setting OVP. Boost OVP fault will be triggered when boost output voltage raises above ~1.6V from expected adaptive boost voltage or if output voltage is being set in manual mode, OVP will be set if boost output voltage raises above ~1.6V from initial boost voltage setting.

Best Regards,

Salome

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CCS / LP8860-Q1：Fault pin