LP5018 datasheet(15/59 Pages) TI2

15 / 59 page

resolution and 3 bits of digital dithering control. For 3-bit dithering, every eighth pulse is made 1 LSB longer to

increase the average value by 1 / 8th. The LP50xx device allows users to enable or disable the dithering function

through the PWM_Dithering_EN register. When enabled (default), the output PWM duty-cycle accuracy is 12

bits. When disabled, the output PWM duty-cycle accuracy is 9 bits.

To eliminate the audible noise due to the PWM switching, the LP50xx device sets the PWM switching frequency

at 29-kHz, above the 20-kHz human hearing range.

7.3.1.4 PWM Phase-Shifting

A PWM phase-shifting scheme allows delaying the time when each LED driver is active. When the LED

drivers are not activated simultaneously, the peak load current from the pre-stage power supply is significantly

decreased. The scheme also reduces input-current ripple and ceramic-capacitor audible ringing. LED drivers are

grouped into three different phases.

• Phase 1—the rising edge of the PWM pulse is fixed. The falling edge of the pulse is changed when the duty

cycle changes. Phase 1 is applied to LED0, LED3, …, LED21.

• Phase 2—the middle point of the PWM pulse is fixed. The pulse spreads in both directions when the PWM

duty cycle is increased. Phase 2 is applied to LED1, LED4, …, LED22.

• Phase 3—the falling edge of the PWM pulse is fixed. The rising edge of the pulse is changed when the duty

cycle changes. Phase 3 is applied to LED2, LED5, …, LED23.

Phase 1

Phase 2

Phase 3

Cycle Time

Phase 1

Phase 2

Phase 3

LED1

LED4

LED[3h (n-1)+1]

LED0

LED3

LED[3h (n-1)]

LED2

LED5

LED[3h (n-1)+2]

Figure 7-4. PWM Phase-Shifting

7.3.2 LED Bank Control

For most LED-animation effects, like blinking and breathing, all the RGB LEDs have the same lighting pattern.

Instead of controlling the individual LED separately, which occupies the microcontroller resources heavily, the

LP50xx device provides an easy coding approach, the LED bank control.

Each channel can be configured as either independent control or bank control through the LEDx_Bank_EN

intensity-control registers. When LEDx_Bank_EN = 1, the LP50xx device drives the LEDs in LED bank-control

mode. The LED bank has its own independent PWM control scheme, which is the same structure as the PWM

scheme of each channel. For more details, see PWM Control for Each Channel. When a channel is configured in

www.ti.com

LP5018, LP5024

SLVSEB8C – OCTOBER 2018 – REVISED JULY 2024

Submit Document Feedback

Product Folder Links: LP5018 LP5024

LP5018 Datasheet(PDF) 15 Page - Texas Instruments

LP5018 Datasheet(HTML) 15 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59

Datasheet Download

Link URL