11

FN6213.1

January 27, 2006

Leakage Considerations

Reverse ESD protection diodes are internally connected

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

of these diodes conducts if any analog signal exceeds V+

or V-.

Virtually all the analog leakage current comes from the ESD

diodes to V+ or V-. 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 V- 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 V- 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 GND.

FIGURE 9. ON RESISTANCE vs SUPPLY VOLTAGE

FIGURE 10. ON RESISTANCE vs SWITCH VOLTAGE

FIGURE 11. ON RESISTANCE vs SWITCH VOLTAGE

FIGURE 12. ON RESISTANCE vs SWITCH VOLTAGE

30

40

50

60

70

100

200

300

400

-40

°C

85

°C

V- = 0V

V+ (V)

4

6

8

10

12

357

9

11

2

0

20

V- = -5V

25

°C

-40

°C

85

°C

25

°C

20

30

40

50

60

30

40

50

60

70

80

90

50

60

70

80

90

100

110

120

-4

-2

0

2

4

-5

-3

-1

1

3

5

25

°C

85

°C

25

°C

-40

°C

85

°C

-40

°C

25

°C

-40

°C

85

°C

75

100

150

200

225

60

80

100

120

140

160

40

50

60

70

80

90

100

02

4

13

5

V+ = 2.7V

V+ = 5V

25

°C

-40

°C

85

°C

V- = 0V

25

°C

-40

°C

85

°C

V- = 0V

25

°C

85

°C

-40

°C

V- = 0V

V+ = 3.3V

175

125

02

46

8

10

12

20

25

30

35

40

45

50

55

60

-40°C

85

°C

25

°C

V+ = 12V

V- = 0V

ISL84582