DM180021 Microchip Technology Inc., DM180021 Datasheet - Page 39

• Manufacturer Part Number: DM180021
• Description: MPLAB Starter Kit for PIC18F MCU
• Manufacturer: Microchip Technology Inc.

Specifications of DM180021

• Contents: MicroSD™ memory cardAcceleration sensorOLED display
• Lead Free Status / Rohs Status: RoHS Compliant part

B.3
© 2009 Microchip Technology Inc.
SOFT START FUNCTIONS AND USAGE
FIGURE B-2:
FIGURE B-3:
A software component on the microcontroller side is also required to manage the PWM
output and control the external circuit. The demo applications supplied with the starter
kit use three different software function calls to manage USB-related power consump-
tion.This section describes the functions provided and how they are used to meet the
USB requirements.
B.3.1
The AppPowerEnable() function starts the soft start sequence. The function initial-
izes the port pins, timers and PWM modules to get ready for the soft start. It is optional
if APP_POWER_AUTO_ENABLE is defined.
In light of the Total Application Current Draw specification of 100 mA, this function
should not be called until after the device is enumerated. See the following section for
more details.
AppPowerEnable()
VARYING PWM OUTPUT TO SLOWLY CROSS THE LINEAR
THE ENTIRE SOFT START PROCESS
REGION OF Q1’S OUTPUT
USB Current Draw Requirements
DS51852A-page 35