High-Precision Voltage Detector - S80745 support needed

Thread Starter

mishra87

Joined Jan 17, 2016
962
Hi All,

Could you please support me below circuit ?
I used S80745 open drain device.

The output of S80745 is connected to RESET pin of ATMEGA103.

My understanding is -

1. 4.7K and 100n provides power ON reset to ATMEGA103
Is this correct ?

2. Voltage detection using S80745
I see the plot of S80745,

When VDD<(-VDET), Vout = Low , For me since reset pin of MCU is low . MCU will stop working.
When VDD>(+VDET), Vout = How , For me since reset pin of MCU is high, MCU goes in normal operation mode.

At the end i am trying to understand the what is the purpose of using S80745 with MCU.
I do not understand how MCU will detect the voltage and what is purpose of it ?

Thanks in Advance !

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Ya’akov

Joined Jan 27, 2019
5,998
Reset ICs are a kind ov Voltage Supervisor specifically designed to protect a CPU from brownout conditions (low PS rail voltage) that can cause unexpected or unintended operation, memory corruption, and other malfunctions.

When a CPU's supply voltage reaches a critical level, it is safer and better to put the CPU into reset than to let it run at the low voltage. If it does, it can do damage to data, or in some cases people and things.

The voltage detector offers a way to monitor the power rail and put the CPU into reset when there is a fault condition. If the power supply returns to normal, the reset is released and the CPU can restart.
 

Thread Starter

mishra87

Joined Jan 17, 2016
962
Reset ICs are a kind ov Voltage Supervisor specifically designed to protect a CPU from brownout conditions (low PS rail voltage) that can cause unexpected or unintended operation, memory corruption, and other malfunctions.

When a CPU's supply voltage reaches a critical level, it is safer and better to put the CPU into reset than to let it run at the low voltage. If it does, it can do damage to data, or in some cases people and things.

The voltage detector offers a way to monitor the power rail and put the CPU into reset when there is a fault condition. If the power supply returns to normal, the reset is released and the CPU can restart.
Hello,
Thanks for your time and useful information.

Best wishes !
 
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