11

FN6213.3

May 6, 2009

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.

Typical Performance Curves

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

024

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