TS12A44513_16 Datasheet, PDF (13/24 Pages) Texas Instruments – Low ON-State Resistance 4-Channel SPST CMOS Analog Switches

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8.2.3 Application Curve
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V_CC = 3 V
TS12A44513, TS12A44514, TS12A44515
SCDS247B – OCTOBER 2008 – REVISED FEBRUARY 2016
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V_CC = 4.5 V
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V_CC = 11.4 V
5
0
0 1 2 3 4 5 6 7 8 9 10 11 12
Analog Signal, V_COM (V)
Figure 10. ON-State Resistance, R_ON vs Analog Signal, V_COM
9 Power Supply Recommendations
The TS12A4451x construction is typical of most CMOS analog switches, except that they have only two supply
pins: VCC and GND. VCC and GND drive the internal CMOS switches and set their analog voltage limits.
Reverse ESD-protection diodes connected in series are internally connected between each analog-signal pin and
both VCC and GND. If an analog signal exceeds V_CC or GND, one of the diodes will be forward biased, but the
other will be reverse biased preventing current flow.
Virtually all the analog leakage current comes from the ESD diodes to VCC 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_CC 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 VCC 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 direct connection between the analog-signal paths and VCC or GND.
VCC and GND also power the internal logic and logic-level translators. The logic-level translators convert the
logic levels to switched V_CC and GND signals to drive the analog signal gates.
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Product Folder Links: TS12A44513 TS12A44514 TS12A44515