Voltage Detectors (Reset ICs): Introduction
A voltage detector is an IC that monitors a certain voltage such as supply voltage. It is sometimes called a reset IC, for it sends a reset signal to the CPU at power-on reset signal detection or at supply voltage abnormality detection. It is also regarded as a kind of supervisor ICs, the same way as watchdog timer ICs which monitor signal cycles of a CPU. Our product lineup includes many voltage detectors with various unique features.
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High-voltage Product
Voltage detectors below feature high voltage tolerance such as input voltage of maximum 60 V and high detector threshold of maximum 48 V. Because high-voltage products can directly monitor high voltages without external resistors for voltage dividers, they can eliminate unwanted currents flowing through the external resistors. These detectors can directly monitor a high supply voltage which an automotive battery or general industrial equipment use.
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Over- and Under-voltage Monitoring (Window-type Detectors)
General voltage detectors have a reference voltage, and they define voltage state lower or equal to the reference voltage as abnormality. On the other hand, window voltage detectors have a function to find both over and undervoltage, and therefore can monitor whether the monitoring voltage is at the desired value or not.
Our window voltage detectors have a high threshold accuracy of ±0.5% (Ta = 25°C), and therefore are suitable for functional-safety-required applications such as automotive and industrial equipment.
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Release Voltage Setting to Adjust Hysteresis Width
Not only the detection voltage, but also the release voltage can be set to a desired voltage. Therefore, the hysteresis width can be set as desired. Adjusting the hysteresis width to compensate for supply voltage fluctuations makes it easier to measure chatter.
Some products can set detection delay time and release delay time.
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Multi-functional Voltage Detectors
Furthermore, our voltage detector lineup includes ones containing a watchdog timer and an LDO regulator in a single chip. They are applicable for voltage monitoring of various applications.
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Small and Thin Package
The following voltage detectors feature small and thin packages enabling high-density mounting. These small-package products help to reduce mounting area and the size of your applications.
Unique Voltage Detectors Available
Besides the products mentioned above, we line up many other voltage detectors with characteristics such as a high threshold accuracy of ±0.5%, low supply current of 290 nA, and a wide operating voltage range of 0.5 to 60 V.
Other features include following: settable detection delay time, manual reset function (MR function), separated VDD-SENSE pins, power on reset function, output inversion, over and undervoltage monitoring function, adjustable detector threshold / release voltage function, and so on.
With these features, our voltage detectors will help to create high value-added applications.
FAQ
Refer to the following FAQs for more details on functions our voltage detectors have.
- How long is the detection delay(td) of R3111 series.
- Is there a problem with pulling up the /RESET pin of the NJU2103A to a voltage source other than the V+ pin voltage
- The RESET output pulse width (tPO) is guaranteed as follows with CT=0.01μF. In addition, the data sheet provides the calculation formula
- Release delay time when Cd pin of R3112 series is open
- What is the Min./Typ./Max. value of detection delay (treset) of R3119 and R3120?