LP8556: LP8556 PWM only

Sreedev K1

Part Number: LP8556

Hi,

I was going through the datasheet and would like to use the WQFN version of LP8556(LP8556SQ-E09/NOPB). But as per the attachment, all WQFN packages belong to PWM only. Does this mean none of the WQFN packages have I2C control? But the pinout diagram has I2C pins. I am confused. Also under the 6 channel WQFN devices, there are three different devices. What are the differences between these different devices?

over 4 years ago

0 Sean Zhou over 4 years ago

TI__Mastermind 22745 points

Hi Sreedev,

All those versions can be re-configured with the I2C that means all devices can be communicated with the I2C interface. The reason behind those kinds of version is that we provide some fixed EPROM versions for some customers who don't have the I2C interface.

Sean

0 Sreedev K1 over 4 years ago in reply to Sean Zhou

Prodigy 70 points

So I'm choosing LP8556SQ-E09/NOPB. What are the differences between SQ, SQE, SQX versions?

0 Sean Zhou over 4 years ago in reply to Sreedev K1

TI__Mastermind 22745 points

Hi Sreedev,

Here is the difference, the only difference is the SPQ, no difference from the spec side:

Sean

0 Sreedev K1 over 4 years ago in reply to Sean Zhou

Prodigy 70 points

Great. Thanks. I'll share my schematic here for a quick review sometime later.

0 Sreedev K1 over 4 years ago in reply to Sean Zhou

Prodigy 70 points

Can you take a quick look at the schematics. VCC_BKLT_15V will go to LED anode and LED_C is cathode.

0 Yuting Shao over 4 years ago in reply to Sreedev K1

TI__Genius 13001 points

Hi,

There are some suggestions:

1. 0.1uF cap. should be close to VDD pin, so you'd better move it after the connected point.

2. Since the Vf@max. is 16V, the output voltage of device should be set higher rather than 15V. You can enable adaptive output voltage function so device can automatically choose the proper output voltage.

3. If you want to get 80mA@max., 25mA per channel is not enough.

BR,

Robin

0 Sreedev K1 over 4 years ago in reply to Yuting Shao

Prodigy 70 points

Thanks for the response.

1. The capacitor placement will be handled in layout.

2. Noted.

3. I was purposely limiting it to around 75mA so that the limit is not exceeded.

Power management

Power management forum

LP8556: LP8556 PWM only