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AS1741

9 Application Information

Power Supply Sequencing

Proper power-supply sequencing is critical for proper switch operation. The power supplies should be started up in the

following sequence:

1. V+

2. NOx, NCx, COMx

Note:

Operation beyond the absolute maximum ratings (see page 2) may permanently damage the devices.

Power Supply Bypass

Power supply connections to the devices must maintain a low impedance to ground. This can be done using a bypass

capacitor, which will also improve noise margin and prevent switching noise propagation from the V+ supply to other

components.

A 0.1µF bypass capacitor, connected from V+ to GND (see Figure 17 on page 11), is adequate for most applications.

Logic Inputs

Driving INx Rail-to-Rail will help minimize power consumption.

Layout Considerations

High-speed switches require proper layout and design procedures for optimum performance.

!

Short, wide traces should be used to reduce stray inductance and capacitance.

!

Bypass capacitors should be as close to the device as possible.

!

Large ground planes should be used wherever possible.

Timing Diagrams and Test Setups

Figure 12.

AS1741/AS1743 Test Circuit and Timing Diagram

Figure 13. AS1742

/AS1743 Test Circuit and Timing Diagram

AS1741/

AS1743

COMx

NOx

35pF

50

Ω

INx

50

Ω

V+

V+

0

0

50%

50%

90%

90%

GND

AS1742/

AS1743

COMx

NCx

35pF

50

Ω

INx

50

Ω

V+

V+

0

0

50%

50%

90%

90%

GND