Nuvo-3100 Series User’s Manual
Copyright © 2014 Neousys Technology Inc. All Right Reserved.
Page 64 of 99
3.7
Ignition Power Control (Nuvo-3100VTC Only)
Nuvo-3100VTC implements the feature of ignition power control module for in-vehicle
applications. It’s a MCU-based implementation that monitors the ignition signal and reacts
to turn on/off the system according to predefined on/off delay. Its built-in algorithm supports
further features such as ultra-low standby power, battery-low protection, system hard-off
and etc. In this section, we’ll illustrate the principle of ignition power control and operations
modes on Nuvo-3100VTC.
3.7.1 Principle of Ignition Power Control
The basic concept of ignition power control module is to control the timing correlation
between ignition signal and system power status. A typical timing correlation can be
described in following diagram.
1) When DC input is supplied to Nuvo-3100VTC, MCU starts to periodically detect ignition
signal. Note that only MCU is working at this moment and the overall power
consumption is less than 2 mW.
2) Ignition signal is active. (Both 12VDC and 24VDC ignition signals are accepted)
3) MCU starts to count a pre-defined power-on delay.
4) Once power-on delay expired, MCU turns on necessary standby power for
Nuvo-3100VTC (3.3VSB & 5VSB).
5) A PWRBTN# pulse is then issued to turn on the system (a similar behavior as you
press the power button on the front panel).
6) Nuvo-3100VTC is booting up and running.
7) After a period of time, the ignition signal is inactive.
8) MCU starts to count a pre-defined power-off delay.
9) Once power-off delay expired, another PWRBTN# pulse is issued to perform a soft-off
for the system (ex. a normal shutdown process for Windows system).
10) Nuvo-3100VTC is completely shut down.
11) As MCU detects system is off, it turns off the standby power for Nuvo-3100VTC, and
then operates in low power mode again (< 2mW power consumption).
