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ADVANCED COMMUNICATIONS & SENSING

DATASHEET

SX8120/21

1V Motor/LED control timer

ACS - Revision 2.2

August 2010

© Semtech Corp.

4.3

Digital input levels

Input thresholds levels scale with VDD. Inputs have an hysteresis based on a Schmitt trigger schematics.

4.4

Debounce on BUTTON pin

The BUTTON pin is active low. For a start/stop command detection, the voltage on the BUTTON pin must be

maintained low during 10ms. Then, a delay of 20ms is necessary before the next start/stop command.

This allow to remove wrong start/stop commands due to oscillations when using of low-cost push buttons.

4.5

NiMH pin

Pin NIMH goes high when VDD is below the NIMH threshold of 1.41V and low when VDD is above the same

threshold.

A 30mV hysteresis allow to remove NiMH pin oscillation when the VDD voltage is near the threshold.

The supply voltage on VDD pin is checked at a 1Hz rate, so the NiMH pin can switch with a delay of 1 seconds

max.

Figure 3. Input level scales with VDD

VDD

VIH

VIL

1

0

VDD

VIL, VIH vs VDD

2

1.5

0.5

0.8

1

1.2

1.4

1.6

1.8

2

Threshold