Dual Audio Analog Switches

FEATURES

• “Clickless” Bilateral Audio Switching
• Guaranteed “Break-Before-Make” Switching
• Low Distortion: 0.003% typ
• Low Noise: 1 nV/√Hz
• Superb OFF-Isolation: 120 dB typ
• Low ON-Resistance: 60 V typ
• Wide Signal Range: VS = 618 V; 10 V rms
• Wide Power Supply Range: 620 V max
• Available in Dice Form

GENERAL DESCRIPTION 
The SSM2402/SSM2412 are dual analog switches designed specifically for high performance audio applications. Distortion and noise are negligible over the full audio operating range of 20 Hz to 20 kHz at signal levels of up to 10 V rms. The SSM2402/ SSM2412 offer a monolithic integrated alternative to expensive and noisy relays or complex discrete JFET circuits. Unlike conventional general-purpose CMOS switches, the SSM2402/SSM2412 provide superb fidelity without audio “clicks” during switching. Conventional TTL or CMOS logic can be used to control the switch state. No external pull-up resistors are needed. A “T” configuration provides superb OFF-isolation and true bilateral operation. The analog inputs and outputs are protected against overload and overvoltage. An important feature is the guaranteed “break-before-make” for all units, even IC-to-IC. In large systems with multiple switching channels, all separate switching units must open before any switch goes into the ON-state. With the SSM2402/ SSM2412, you can be certain that multiple circuits will all break-before-make. The SSM2402/SSM2412 represent a significant step forward in audio switching technology. Distortion and switching noise are significantly reduced in the new SSM2402/SSM2412 bipolar JFET switches relative to CMOS switching technology. Based on a new circuit topology that optimizes audio performance, the SSM2402/SSM2412 make use of a proprietary bipolar JFET process with thin-film resistor network capability. Nitride capacitors, which are very area efficient, are used for the proprietary ramp generator that controls the switch resistance transition. Very wide bandwidth amplifiers control the gate-to-source voltage over the full audio operating range for each switch. The ON-resistance remains constant with changes in signal amplitude and frequency, thus distortion is very low, less than 0.01% max. The SSM2402 is the first analog switch truly optimized for high-performance audio applications. For broadcasting and other switching applications which require a faster switching time, we recommend the SSM2412—a dual analog switch with one-third of the switching time of the SSM2402.
 

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How to Made Double Voltage

A voltage multiplier in its most basic sense works on the principle that "A CAPACITOR IS A CAPABLE OF STORING CHARGE AND THAT IT HAS THE SAME POTENTIAL AS THE SOURCE WHICH CHARGED IT". Now, the whole idea is that in an AC system you use capacitors in such a way that the net output voltage should be, say double of what you would otherwise get. This circuit will be called a voltage doubler. Now lets have a look at the action that actually happens to double the voltage.

 












The image you see is a schematic of a voltage doubler, few things to notice about it. The transformer gives output between points A and B. The load is connected between points A * and B *, but also there are two capacitors between those two points and point C is common to both.

Now to begin analyzing imagine a sine wave coming in. The first diode is forward biased and so conducts and in an attempt to do that it charges the first capacitor, now in the second half cycle of the wave the second diode is forward biased and so the second capacitor is charged. Now since the load is between the two capacitors, it is more like two batteries connected in series with each other.


Thus and the voltage in the series adds up, the net voltage across the load is twice the voltage that the transformer can deliver. Voltage multipliers are most commonly used at places where you wish to have high AC voltage when the transformer of the required rating is not available

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