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LP5018: LP5018 questions

Part Number: LP5018
Other Parts Discussed in Thread: LP5024

Hello,

I would like to use LP5018 LED driver and have few additional questions:

1. It is possible to power LEDs from higher voltage than LP5018 itself (LP5018 powered from 3.3V rail and LEDs from 5V rail) ? In datasheet ihis is neither allowed nor forbidden expressly. Will this work or it can cause problems with leakage from VLED to VCC thru LEDs ?

2. I case that "Auto_Incr_EN" (DEVICE_CONFIG1.3) is changed from 0 (previously written) to 1, will this change take effect immediately (multiple write transaction will continue to next register - LED_CONFIG0) or write transaction need to by terminated after this change (by sending stop condition) to autoincrement change take effect ?

3. Changes in registers (brightness, color) takes effect immediately after whole databyte is sent or is delayed until I2C transaction end (stop is sent) ?

4. Which level is better to set in "Max_Current_Option" (DEVICE_CONFIG1.1) when 25mA (or lower) current is set by Riset and VCC is high enought to support both options? Has change of this bit any impact on device performance in this scenario ?

5. What happend if I2C write transaction targets registers of unavaliable outputs in LP5024 (for example writing registers 03h to 20h in single write transaction with autoincrement), will it nack unavaliable register (and abort transaction by that) or it just ignore data written to this registers (send ack and continue to next register) ?

6. Toggling EN pin (hi-lo-hi) cause device reset (set registers to defaults) or just disable device during low period without affecting register contents ?

7. If thermal protection trip and shutdown device, will it affect register contents and/or I2C communication or just switch off current sinks until temperature gets lower ?

With best regards,

Pavel

  • Hi Pavel,

    (1) The voltage of OUT pins is range from 0 to 5.5V. Larger OUT Pin voltage will damage the device.

    (2) Changes will be taken after 'Auto_Incr_EN' enabled

    (3) Changes take effects immediateky.

    (4) When 'Max_Current_Option' is enabled, you will adjust reference color-mixing and brightness control register to set current to 25mA. Both program are OK. It depend in your minimum adjust step.

    (5) Just ignore data written to this registers

    (6) Device reset

    (7) After temperature gets lower than reference data, the device will directly return to normal status.

    Best Regard

    Monet Xu