XC61F datasheet(5/12 Pages) TOREX

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XC61F

Series

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DIRECTIONS FOR USE

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Notes on Use

1. Please use this IC within the stated maximum ratings. The IC is liable to malfunction should the ratings be exceeded.

2. When a resistor is connected between the VIN pin and the input with CMOS output configurations, oscillation may

occur as a result of voltage drops at RIN if load current (IOUT) exists. It is therefore recommend that no resistor be added.

(refer to Oscillation Description (1) below)

3. When a resistor is connected between the VIN pin and the input with CMOS output configurations, irrespective of N-ch

output configurations, oscillation may occur as a result of through current at the time of voltage release even if load

current (IOUT) does not exist. (refer to Oscillation Description (2) below)

4. With a resistor connected between the VIN pin and the input, detect and release voltage will rise as a result of the IC's

supply current flowing through the VIN pin.

5. If a resistor (RIN) must be used, then please use with as small a level of input impedance as possible in order to control

the occurrences of oscillation as described above.

Further, please ensure that RIN is less than 10kΩ and that CIN is more than 0.1μF (Figure 1). In such cases, detect

and release voltages will rise due to voltage drops at RIN brought about by the IC's supply current.

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Oscillation Description

(1) Oscillation as a result of output current with the CMOS output configuration:

When the voltage applied at IN rises, release operations commence and the detector's output voltage increases. Load

current (IOUT) will flow through RL. Because a voltage drop (RIN x IOUT) is produced at the RIN resistor, located

between the input (IN) and the VIN pin, the load current will flow via the IC's VIN pin. The voltage drop will also lead to

a fall in the voltage level at the VIN pin. When the VIN pin voltage level falls below the detect voltage level, detect

operations will commence. Following detect operations, load current flow will cease and since voltage drop at RIN will

disappear, the voltage level at the VIN pin will rise and release operations will begin over again.

Oscillation may occur with this " release - detect - release " repetition.

Further, this condition will also appear via means of a similar mechanism during detect operations.

(2) Oscillation as a result of through current:

Since the XC61F series are CMOS ICS, through current will flow when the IC's internal circuit switching operates

(during release and detect operations). Consequently, oscillation is liable to occur during release voltage operations

as a result of output current which is influenced by this through current (Figure 3).

Since hysteresis exists during detect operations, oscillation is unlikely to occur.

Figure 1. When using an input resistor

XC61F Datasheet(PDF) 5 Page - Torex Semiconductor