MCP1664 datasheet(17/28 Pages) MICROCHIP

Numer części	MCP1664

Szczegółowy opis	MCP1664 LED Driver Evaluation Board

PDF	28 Pages

Scroll/Zoom	100%

Producent	MICROCHIP [Microchip Technology]

Strona internetowa	http://www.microchip.com

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Installation and Operation

 2015 Microchip Technology Inc.

DS50002363A-page 17

The R1 and R2 resistors affect not only the operating frequency but also the amplitude

of the triangular wave. Considering the maximum voltage of the triangular waves

(VTH) and the minimum voltage of the triangular waves (VTL), the amplitude swing and

the threshold voltages can be calculated by means of the following equation:

EQUATION 2-3:

TRIANGULAR WAVE AMPLITUDE SWING

For the MCP1664 LED Driver Evaluation Board, the components were chosen so that

they feature a PWM Dimming frequency of 125 Hz and an amplitude swing from

5% VDD to 95% VDD.

FIGURE 2-5:

Obtaining the Dimming Signal - 84% Duty Cycle.

VTH VTL

–

------VDD

Where: R4 <R2

REFERENCE

VOLTAGE

DIMMING

SIGNAL

TRIANGULAR

WAVE

MCP1664 Arkusz danych(PDF) 17 Page - Microchip Technology