Microchip MEC1428 Handleiding


Lees hieronder de 📖 handleiding in het Nederlandse voor Microchip MEC1428 (38 pagina's) in de categorie Niet gecategoriseerd. Deze handleiding was nuttig voor 15 personen en werd door 2 gebruikers gemiddeld met 4.5 sterren beoordeeld

Pagina 1/38
 2017 Microchip Technology Inc. DS00002137B-page 1
INTRODUCTION
Pulse Width Modulation (PWM) modules, which produce basically digital waveforms, can be used in many applications
as a more efficient and lower power alternative to the traditional 8 bit Digital-to-Analog (D/A) converters using only two
inexpensive filter components. A wide variety of microcontroller applications that exist today are better served by utiliz-
ing a PWM generated analog output as opposed to an 8 bit D/A converter. One application where using a high resolution
PWM has value vs. a traditional 8 Bit DAC is in driving the 3-wire voltage controlled fan in a PC.
Audience
This document is written for a reader that is familiar with hardware design. The goal of this application note is to provide
information regarding how to use a PWM to drive 3-wire fans that provides system benefits and an enhanced customer
experience.
References
The following documents should be referenced when using this application note. Please contact your Microchip repre-
sentative for availability.
• Microchip MEC140x/MEC141x/MEC142x Data Sheet
• Microchip MEC140x/MEC141x/MEC142x EVBs
AN2137
PWM Controlled Fan for MEC140x/MEC141x/MEC142x
Author: Tom Tse / Greg VanWesten

Microchip Technology Inc.
AN2137
DS00002137B-page 2  2017 Microchip Technology Inc.
1.0 OVERVIEW
Key potential benefits of using a high resolution PWM generated analog output for 3 wire fan control include:
• Finer RPM resolution (4x) control vs a traditional 8 bit DAC.
• Finer RPM control can potentially solve the issue of having two consumer platforms at the same thermal condition
each running at a different RPM Zoned speed – since the finer control would allow you to control RPM closer to
mechanical resonant points of the box and thus significantly reduce the chance of one machine running at differ-
ent binned zone speeds).
The purpose of this white paper is to show the benefits of using the MEC140x/MEC141x/MEC142x 16 bit PWM vs a
traditional 8 bit DAC to control 3 wire fans. (see typical schematic of a 3 wire fan drive in Figure 1-1 by DAC and Figure 1-
2 by PWM).
Note: A typical PC has up to 10 bands (zones) of RPMs that they run the fan in – stepping around mechanical
resonant frequencies of the platform.
FIGURE 1-1: 3-WIRE FAN DRIVE BY DAC
MEC140x/
MEC141x/
MEC142x
Fan
Driver
(e.g.
APL5606)
VFSM
VIN
VSET
DAC
+5V
+3.3V
TACH
2.2uF
VOUT = 1.6 x VSET
2.2uF 1000pF
Fan Connector
10k
0.01uF
3-Wire Fan
Fan Volt
TACH
GND
 2017 Microchip Technology Inc. DS00002137B-page 3
AN2137
FIGURE 1-2: 3-WIRE FAN DRIVE BY PWM WITH R/C FILTER
MEC140x/
MEC141x/
MEC142x
Fan
Driver
(e.g.
APL5606)
VFSM
VIN
VSET
PWM
(1KHz)
TACH
10k
10uF
2.2uF
VOUT = 1.6 x VSET
2.2uF 1000pF
0.01uF
3-Wire Fan
Fan Volt
TACH
GND
+5V
Fan Connector
+3.3V
10k


Product specificaties

Merk: Microchip
Categorie: Niet gecategoriseerd
Model: MEC1428

Heb je hulp nodig?

Als je hulp nodig hebt met Microchip MEC1428 stel dan hieronder een vraag en andere gebruikers zullen je antwoorden




Handleiding Niet gecategoriseerd Microchip

Handleiding Niet gecategoriseerd

Nieuwste handleidingen voor Niet gecategoriseerd