LP8865C-Q1: 60 LED'S IN Series Parallel combination

Pavan Kumar Adapa

Part Number: LP8865C-Q1
Other Parts Discussed in Thread: LP8868X-Q1

Tool/software:

Hi Team,

We are planning to use LP8865C-Q1 LED driver, to my application to drive the 60 LED's which is in series parallel combination.

10 LED's in Series String and 6 parallel combinations

LED Rating - Forward Voltage - 3.2 V Forward Current - 700 mA.

Is this part is useful for my application

2 months ago

0 Suchen Dong 2 months ago

TI__Expert 3381 points

Hi Paven,

One LP8865C cannot support a 32V 4.2A output. You may have to try use multiple LP8865C-Q1 or higher power version LP8868-Q1.

The design is highly related to input voltage range. Please provide more information on this.

Best regards,

Suchen

0 Pavan Kumar Adapa 2 months ago in reply to Suchen Dong

Prodigy 140 points

Hi Suchen,

The Input Voltage is 12 V

0 Suchen Dong 2 months ago in reply to Pavan Kumar Adapa

TI__Expert 3381 points

Hi Pavan,

For 12V input, one LP8865C can support one string output 700mA, 32V.

0 Pavan Kumar Adapa 2 months ago in reply to Suchen Dong

Prodigy 140 points

We are planning to use LP8868-Q1 for my application in a Boost topology.

connecting 10 LED in series string in 6 parallel combinations. (Voltage - 32 V, current -4.2 A) . Can You suggest we can go forward with this approach?

0 Pavan Kumar Adapa 2 months ago in reply to Pavan Kumar Adapa

Prodigy 140 points

Will LP8868-Q1 Support 4.2 A Current drive in Boost topology Mode.

+1 Suchen Dong 2 months ago in reply to Pavan Kumar Adapa

TI__Expert 3381 points

Hi Pavan,

For LP8868X-Q1 (Boost version), the current limit of the internal FET is 6.5A. Without considering the thermal problem, 12V VIN, 32V 4.2A output requires 15A current limit when efficiency = 90%, inductor current ripple = 40%.

So, we recommend using 3 separate LP8868X to driver your LED loads, each with 2 strings.

Best regards,

Power management

Power management forum

LP8865C-Q1: 60 LED'S IN Series Parallel combination