LP5520 with regulated 5V supply

Hi Per-Ola,

Yes you can use the LP5520 without the boost.

You need to connect the VDDA and VDDD to your battery/voltage supply (2.7V to 5.5V) and have the input caps for these (100 uF).

You can leave the SW and FB pins floating.

Yes, you need to make sure with I2c or SPI writing that the DCDC is disabled (en_boost bit).

Also note that if you would like to reprogram the EEPROM, then you would need to have the boost working.

Regards,

Sami

Pär-Ola,

There are default temperature compensation values in the EEPROM, so you can use the auto temperature compensation with these. These values are set for a certain RGB, so you might want to reprogram your own values. Regarding that this is somewhat older product, the default compensation values are also for older RGB.

If you want to reprogram the EEPROM you would need either to use the Boost converter of LP5520 or you could apply 18V to the FB. Programming the EEPROM with external 18V has not been tested, so that was the reason why I suggested you would need the boost converter.

Basically programming should work when feeding 18V to the FB pin, but at this point I cannot ensure this. See info about the EEPROM programming below

1. Boost related components should be assembled - during EEPROM programming device will use about 18V from boost for burning.
2. Set NSTBY bit (bit 0 register control 06H)
3. Reset en_boost bit (bit 1 register control 06H)
4. Write 12H value to boost output register 05H
5. Choose SRAM page for data - ee_page[1:0] bits - bits 0 and 1 EEPROM_control register (0DH)
6. Write EEROM context for this page to SRAM, address 40H-5FH
7. Repeat step 5 and 6 for every page.
8. Erase EEPROM - set and reset ee_erase bit (bit 6 EEPROM_control register 0DH), wait 100ms
9. Burn EEPROM -  set and reset ee_prog bit (bit 6 EEPROM_control register 0DH), wait 100ms

Regards,

Sami