9

FN6043.3

January 23, 2006

voltage divider action of the switch OFF impedance and the

load impedance.

Leakage Considerations

Reverse ESD protection diodes are internally connected

between each analog-signal pin and both V+ and GND. One of

these diodes conducts if any analog signal exceeds V+ or

GND.

Virtually all the analog leakage current comes from the ESD

diodes to V+ or GND. Although the ESD diodes on a given

signal pin are identical and therefore fairly well balanced,

they are reverse biased differently. Each is biased by either

V+ or GND and the analog signal. This means their leakages

will vary as the signal varies. The difference in the two diode

leakages to the V+ and GND pins constitutes the analog-

signal-path leakage current. All analog leakage current flows

between each pin and one of the supply terminals, not to the

other switch terminal. This is why both sides of a given

switch can show leakage currents of the same or opposite

polarity. There is no connection between the analog signal

paths and V+ or GND.

FIGURE 8. ON RESISTANCE vs SUPPLY VOLTAGE

FIGURE 9. ON RESISTANCE vs SWITCH VOLTAGE

FIGURE 10. DIGITAL SWITCHING POINT vs SUPPLY VOLTAGE

FIGURE 11. SUPPLY CURRENT vs DIGITAL ADDRESS INPUT

VOLTAGE

25

7

9

11

12

0

100

200

300

400

500

V+ (V)

-40

°C

85

°C

25

°C

3

4

6

8

10

13

0

4

6

8

10

12

2

V+ = 3.3V

30

40

50

60

70

80

85

°C

-40

°C

25

°C

V+ = 12V

60

80

100

120

140

25

°C

-40

°C

85

°C

V+ = 5V

75

100

150

200

225

175

125

25

°C

-40

°C

85

°C

V+ (V)

25

3.0

2.5

2.0

1.5

1.0

0.5

34

6789

10

11

12

13

3.0

2.5

2.0

1.5

1.0

0.5

-40

°C

85

°C

-40

°C

85

°C

25

°C

25

°C

01.5

0.51

22.5

33.5

44.5

5

70

60

50

40

30

20

10

0

V+ = +5V

ISL43640