#1109

Episode 1109 chip of the day
A look at some analog switches
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[@mariuszkalecinski7184]

I really appreciate that you listen to the vievers' sugestions and produce videos on the requested topics in such a short time. Keep it up!

[@VoidHalo]

When I was new to electronics 5 years ago, I didn't know where to get ICs from yet. So, it was common for me to try (key word) to recreate logic chips on a breadboard using discrete parts. This was one of them. Trying to use a 2N7000 and a BS250 to form the transmission gate, and one more 2N7000 for the inverter. Needless to say, it didn't work because the MOSFETs were far from matched. But, I still learned a great deal about transmission gates, and about the 4066 without ever having to touch one.

[@nigeljohnson9820]

I prefer the 74HC4053 change over switch in audio designs. These only have three change over switches in a single package, that is three, single pole, double throw. This allows the audio channel to be switched between pass through and the analogue ground. This tends to produce a much higher signal isolation and a lower noise output when in the off state. I have used these in op-amp signal processing and summing circuits. They also can be used to produce switch, and commutating capacitor filters. Toshiba made an analogue switch with opto isolated control, the TLP597G, it has a very low on resistance, making it ideal for isolating i2C data and clock lines, when the connected peripheral is powered off. I,e when the i2C bus has peripherals that are separately powered. Without such isolation, switching off a peripheral, results in a short on the bus.

[@AnalogDude_]

the downside is that's only 20 V (bipolar) and if you system is 24 V bipolar, you have to find a work around. did you check these DG411/DG412/DG413?

[@nigeljohnson9820]

@@AnalogDude_ in my case I was working on a professional telecom system, which was designed to use +/- 5 and 12 volts. Our systems used a negative earth, 24 volt rack supply, a standard SELF for radio telecommunication system. As all the audio circuits were powered from the +/- 5 volt supply, with 0 volt reference, the 74HC4053 was an ideal choice. The I2C bus system is distributed over a number of independently powered screened boxes, with several feet of cable connecting them together. The I2C provided a multi-drop bus. Not very fast by modern standards, but useful for a home automation system. It came from work I did almost 40 years ago, on a base site control system.

[@AnalogDude_]

​@@nigeljohnson9820 i have built the national fiberglass network in the telecom exchanges around 1999/2000. :) many MCU's /microchip, ATMEL, ST, etc, etc) have communication port(s) that be configured as either I2C, SPI or CANBUS. i made a Voltage controlled switch for my modular synthesizer and used the Cd4053. works great, but i had to build a separated power supply using opamps to scale down from +/-12 V. to save on PCB space i would like to give the DG series chip a change. Since "Analog Devices" also makes them, they should be al rite, i guess. the CD4053 has a resistance of like 150 OHm's being powered from a bi polar 10 volt supply and these DG series like 1/3 or less than that. the CD4053 is like 50 years old and it seams the DG series are made around 2005, dates i could read from datasheets.

[@nigeljohnson9820]

@@AnalogDude_ thè 4066 also date back 50 years. When i was using the 4053 they would have been only 10 years old.

[@AnalogDude_]

@@nigeljohnson9820 i got a few (CD4066) laying around, but not yet used so far, it seemed strange to me no having the GND pin (being used on a bipolar supply), like the CD4051, Cd4052 and CD4053 have. they didn't include a circuit overview of the Texas Instruments CD4053, don't know if the GND pin used only for the logic side. the Renesas DG411/412/413 datasheet shows the GND input is used on the long tail inside.

[@lelandclayton5462]

I built a four channel power supply years ago and used a DG441 to switch between the channels to display the output of the meter.

[@leosbagoftricks3732]

Measuring the switch resistance with a floating external meter is going to give you bad readings, especially when the switch is open. You need to be sure the voltage applied is referenced to the supply, so it stays between the rails. Bias one switch input to a known voltage so you know it's stable and within the allowed range.

[@d942yd42]

Thanks, IMSAI Guy!

[@gregvanpaassen]

For audio use these have quite high distortion, so they are best used in a way where the signal path does not go through the switch. E.g. IN -> 2k resistor -> top of switch to ground -> second 2k resistor -> top of second switch to ground -> OUT. When both switches are on (50R to ground) the "offness" is fairly good ( (50/2050)^2, -148 dB), and the signal does not pass through either switch when it is being used. Downside is you might need a buffer at OUT depending on the input impedance requirements of the following circuitry.

[@t1d100]

Good tutorial! Thanks!

[@SuperFredAZ]

Motorola ALWAYS put a "1" in front of their "4000" (metal gate CMOS) series parts. The RCA parts were 4066 and the Motorola parts were MC14066. When the HC series (silicon gate CMOS) for Motorola were MC74HXXXX, same as all other except for the "MC"

[@joeteejoetee]

Thanks for making this video!

[@M0rE_e]

i really appreciate this video really helped me find what i was looking for literally my whole GP depends on that switch

[@reverend11-dmeow89]

I used these in a guitar effects footswitch 'consolidator' monster footpedal thingy, which was great. I did not, however, manage to decipher Switch Bounce issues that the guy I built it for chastised me greatly for my not having tested it in the same environment, "Live On-Stage" where "130dB S:KCITttt!" echoing on ever footswitch hit managed to destroy the show. :-( I went through at least half a bakers dozen reference books seeking solace for Switch Bounce mitigation. What is(are) the Ruling Lesson(s) for this area, Maestro? These TI 8-by and 16-by (74HC4067) Analog Multiplexers? Do you know of any working fixes for similar gotchas in this switch bounce area, whether MCU- or Manual-controls, for these ICs?

[@davidjh7]

I recall the 4066 could use plus and minus supply voltages, although the range was pretty limited. My memory is a bit fuzzy on that.

[@mortenrobinson5421]

I have found an interesting circuit, that makes use of a CD4066. Can I use an analog multiplexer in place of this component? I was thinking that simply switching between 2 analog inputs on an analog multiplexer would accomplish the same thing as the 4066.

[@youtuuba]

As at least a couple others have noted in these comments, I was going to say that the method used in this video for measuring the 'switch' resistance on the 4066, 'off' state in particular, is not valid, or at least problematic. To get valid results, the circuit doing the resistance testing ( the digital multimeter in this video) needs to have some commonality with the 4066's power supply, ground reference, etc. That this was not done in this video demonstration is probably why the 'off' state resistance measurements were so disappointingly low (although in the M Ohm range, still not 'practical infinity') and drifty. Also, while enhanced versions of the 4066, or similar ICs with better specifications, were mentioned, it is worthwhile recalling that the 4066 is an enhanced 4016, and although the 4066 is better than the 4016 in most ways, the older chip is still better in some subtle ways; even the TI datasheet I checked for the 4066 says right out that the 4016 is better in 'sample and hold' applications than the 4066.

[@francoisdastardly4405]

To more accurate measurement the off state leaking probably you need a relatively low impedance ohmmeter like analog one. Maby the P/N FETs leak is to high for the very low current of digital ohmmeter. Sorry for my horrible english. Thanks for your cool videos !!

[@frankowalker4662]

Cool. I did'nt know these were a thing. :)

[@DoktorJeep]

I was able to switch UARTs with this, but when trying it with CAN busses it acted funny

[@4DRC_]

Might make a good T/R switch in some bespoke radio applications. Like a QRP radio with EFHW or some other high impedance antenna.

[@IMSAIGuy]

no, very low current only. you could transmit a few milliwatts max

[@luclachapelle3499]

LOL ... a typical relay has an on resistance between 50 to 250 ohm Comparable !

[@Enigma758]

2:22 - I puzzled a bit over why both an N and a P channel are required even though they are both open and closed at the same time. My conclusion is that it allows bidirectional current flow when it is open (despite the claim that some make that a mosfet is bi-directional).

[@IMSAIGuy]

it is due to biasing. since you do not have control over the voltages on the inputs, you need to cover all scenarios.

[@urlkrueger]

Well, that was a bit of a switcheroo. Yuk, Yuk. And as an added bonus at no extra cost, no switch bounce.

[@markbratcher9095]

It would be interesting to compare the switch characteristics of the 4066 or DG441 to, for example, the ADG715 (Octal SPST analog switch) and the MAX14662 (also Octal SPST analog switch). Both of these have much lower on resistance than the the 4066 or DG441.

[@tonguescum5137]

Nice video thanks

[@rene0]

Is there a difference between (analog) switches and multiplexers or are they basically the same thing, just other pin configuration/io select?

[@IMSAIGuy]

multiplexers are just analog switches all together

[@tubeDude48]

Have a look at a *74123* They were terrible UN-reliable! And changed it's timing. The external C & R *WAS* *NOT* the problem!!

[@IMSAIGuy]

I remember the 123 but don't think I every used one.

[@tubeDude48]

@@IMSAIGuy - Back when there was nothing but TTL Chips, this chip was popular. It had terrible RUN-AWAY.

[@AnalogDude_]

there are ic's more that aren't available anymore, like the adders and some others.

[@mepacrina9291]

My hc123 work ok ( i used to generate a 200ns pulse for sampling hc4066 in an IQ extraction circuit ) .

[@marka1986]

If I recall there was 4016 as well, and believe the on resistance was a bit hight than the 4066.

[@davidjh7]

The 4016 has a lower on resistance, but also a lower off resistance---old guy here who used both :)

[@mepacrina9291]

4016 was a better choice for chopped amp and multi ramp adc because of lower C (Q injection) . I used also "hand made" switch with cd 4007 and fets. Now ... ( in 2000+ ) analog devices made almost ideal switches so is no more fun in designing and struggle to do precision with non ideal components.

[@AnalogDude_]

DG411/DG412/DG413, also similar to the CD4066 DG441/DG442, seams to best at just 4 Ohm's (says maxim's datasheet). Are there DIP8 versions? CD4066B works bipolar and you absolutely can use the 74HCT4066 in a bipolar fashion, albeit +/- 2.5 volt :)

[@IMSAIGuy]

8 pin: www.mouser.com/datasheet/2/256/MAX317-MAX319-1292538.pdf

[@AnalogDude_]

@@IMSAIGuy Thank you, they have been Eaglized.

[@simontay4851]

v

[@dixsusu]

Here at tti co uk we sttill use CD4052 CD4053 .