LTC3220 LED Driver 5-volt power supply

Hello,

The charge pump does not need to be used if the LEDs are going to be connected to a 5.1V input. It might still be good to have a small cap on the CPO output just for stability. This can be a 1uF 0402 cap. The flying caps do not need to be connected but the charge pump should be forced to 1x mode if possible. This will prevent the charge pump from trying to run case something happens to one of the LED connections or LEDs causing a ULED pin to drop out and start the charge pump. 

Hi Marty,
Thank you for the suggestions.
We will force 1x mode by writing 0x06 to addr 0x00.

For the CPO decap, last week, I received your DC1265A-B demo board, and modified it for 5V only operation:
  1. Cut the PCB track between the LED anodes and C3/CPO pin 28.
  2. Connected 5.1V to both "VIN" and LED Anode test points (silk labelled "CPO VIN-5.1V").
  3. Removed CP caps C1 & C2 on pins 27, 23, 26, 22
  4. Removed CPO cap on pin 28
  5. Added jumper wire from RST to DVCC (1V8).

Results:
  -Observed CP and CPO pins static, no oscillations
  -No unusual VIN current probe waveform
  -All LEDs channels operating fine at 0 to 20mA at 5V anode

So we proceeded to lay out our production PCB with the CP pins and CPO pin 28 as no connect. Our PCB is dense. We will consider the risk of changing the PCB to add the 0402.

Thank you again for your suggestions.