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XC61C Series

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NOTES ON USE

1. Please use this IC within the stated absolute maximum ratings. For temporary, transitional voltage drop or voltage rising

phenomenon, the IC is liable to malfunction should the ratings be exceeded.

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

occur as a result of voltage drops at RIN if load current (IOUT) exists. (refer to the Oscillation Description (1) below)

3. When a resistor is connected between the VIN pin and the power supply with CMOS output configurations, irrespective of

N-ch open-drain 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 the Oscillation Description (2) below )

4. Please use N-ch open drain output configuration, when a resistor RIN is connected between the VIN pin and power source.

In such cases, please ensure that RIN is less than 10kΩ and that C is more than 0.1μF, please test with the actual device.

(refer to the Oscillation Description (1) below)

5. With a resistor RIN connected between the VIN pin and the power supply, the VIN pin voltage will be getting lower than the

power supply voltage as a result of the IC's supply current flowing through the VIN pin.

6. In order to stabilize the IC's operations, please ensure that VIN pin input frequency's rise and fall times are more than 2 μ s/ V.

7. Torex places an importance on improving our products and its reliability.

However, by any possibility, we would request user fail-safe design and post-aging treatment on system or equipment.

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Oscillation Description

(1) Load current oscillation with the CMOS output configuration

When the voltage applied at power supply, release operations commence and the detector's output voltage increases.

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

power supply 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 XC61C series are CMOS IC S, through current will flow when the IC's internal circuit switching operates (during

release and detect operations). Consequently, oscillation is liable to occur as a result of drops in voltage at the through

current's resistor (RIN) during release voltage operations. (refer to Figure 3)

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

Power supply

Power supply

Power supply