WSH41S Datasheet, PDF (6/8 Pages) Winson Semiconductor Corp. – Hall Effect Sensor IC with Thermal Lock Protection ,Auto Restart and Speed Control Function

Application Circuit:
WSH41S
Figure 1.
WSH41S with power sleep function is designed for reducing power consumption and
noise for smart cooling in various applications especially for portable computer
systems while system processors are not in full loading.
1. Green PC System: PC and Notebook systems switch to sleep mode and start
screen savor when CPU is in idle state. Mean while, system can apply an active low
signal V_PS to enable WSH41S power sleep function which makes DC fans of CPU
cooler and even VGA card stop running until CPU loading is heavy again in order
to reduce unnecessary power consumption.
2. CPU with Temperature Sensor Feature: System can detect CPU junction
temperature that reflects the CPU operating status. If CPU is not in heavy loading,
junction temperature is not high enough to affect CPU operation, there is no need to
start DC fan to consume extra power. System designer can simply program the
system based on two CPU temperatures to apply a proper input signal to enable or
disable WSH41S power sleep function. For example, when CPU junction
temperature drops to point A (CPU is in idle state or lightly loading), system
enables WSH41S power sleep function. At this point, DC fan stops running and
consumes power as low as 2mA typically. If CPU junction temperature increases to
Winson reserves the right to make changes to improve reliability or manufacturability.
©Winson, 2004/3/3
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