Application Specific IC

[Electrostatic]

Hello Experts out there, I have a question.
I am looking for an application specific IC that converts to and from logic levels. For example, I would like to switch 320mVDC to 5VDC, without changing the reference voltage of 0V. With the restriction of not using negative voltage in the circuitry and source voltage is 3.3Vdc. The situation is that the voltage levels from our microcontroller, which is TTL Logic, is not compatible with the external peripheral circuits that are on different voltage levels(HIGHS and LOWS).


In other words, I would like to match up the voltage level of my peripheral with the voltage level of my microcontroller.

I would like some help on figuring out how to align or adjust efficiently between logic levels. Any and all information is appreciated

 

[akg]

I am looking for an application specific IC that converts to and from logic levels. For example, I would like to switch 320mVDC to 5VDC, without changing the reference voltage of 0V.

That's an inverter..

With the restriction of not using negative voltage in the circuitry and source voltage is 3.3Vdc.

the power supply is 3.3 and o/p be 5 , a dc-dc conv reqd?, Y this 3.3v supply limitation?

 

[Nigel Goodwin]

Hello Experts out there, I have a question.
I am looking for an application specific IC that converts to and from logic levels. For example, I would like to switch 320mVDC to 5VDC, without changing the reference voltage of 0V. With the restriction of not using negative voltage in the circuitry and source voltage is 3.3Vdc. The situation is that the voltage levels from our microcontroller, which is TTL Logic, is not compatible with the external peripheral circuits that are on different voltage levels(HIGHS and LOWS).


In other words, I would like to match up the voltage level of my peripheral with the voltage level of my microcontroller.

I would like some help on figuring out how to align or adjust efficiently between logic levels. Any and all information is appreciated

You might check the many previous threads about this. Generally though it depends entirely on EXACTLY what you are doing - usually (at least with PIC's) you can use a piece of wire one way, and a single resistor the other. Check my RF module tutorial that uses a 3.3V radio module.

 

[Electrostatic]

I am looking for an application specific IC that converts to and from logic levels. For example, I would like to switch 320mVDC to 5VDC, without changing the reference voltage of 0V.

That's an inverter..

With the restriction of not using negative voltage in the circuitry and source voltage is 3.3Vdc.

the power supply is 3.3 and o/p be 5 , a dc-dc conv reqd?, Y this 3.3v supply limitation?

The project that we are doing is involving the HC12 microcontroller and the power supply is coming from the playstation. The playstation is suppling around 3.3V. We are trying to amplify the attention signal of the playstation which is around 320mVDC because the program that was uploaded into the microcontroller is not reading the attention signal because the signal is to low of a voltage. The HC12 has to see the voltage at around a min of 2.0V and a max of 0.8V. According to the TTL logic level standard. So since it cannot see (read) the attention signal the program that was written for it is not working.

We are trying to amplify this signal and so we were going to use an opamp but we are trying to avoid a using negative voltage and so my comrade proposed the idea of using an Application Specific IC that can perhaps perform this amplification and reduce the circuitry.

 

[Nigel Goodwin]

The project that we are doing is involving the HC12 microcontroller and the power supply is coming from the playstation. The playstation is suppling around 3.3V. We are trying to amplify the attention signal of the playstation which is around 320mVDC because the program that was uploaded into the microcontroller is not reading the attention signal because the signal is to low of a voltage.

320mV sounds far too low to be a 3.3V logic HIGH signal?, have you measured it with a scope?, and is there perhaps something loading the line and pulling it down?.

 

[Oznog]

Not really an ASIC BTW. You're looking for a general purpose IC.

 

[audioguru]

We are trying to amplify the attention signal of the playstation which is around 320mVDC.

We are trying to amplify this signal and so we were going to use an opamp but we are trying to avoid a using negative voltage.

A single supply opamp like an LM358 dual or a MC33171 single can amplify signals from 0V to about +2.1V for the LM358 or to about 2.7V with the MC33171 with a single +3.3V supply.
A Charge-pump voltage-doubler IC can be used to supply the opamp with about 6.2V (they aren't perfect) so its max output voltage would be about 5.0V to 5.6V.
A Cmos opamp would have a max output voltage of 3.3V with a 3.3V supply and a high impedance load.

 

[Electrostatic]

We are trying to amplify the attention signal of the playstation which is around 320mVDC.

We are trying to amplify this signal and so we were going to use an opamp but we are trying to avoid a using negative voltage.

A single supply opamp like an LM358 dual or a MC33171 single can amplify signals from 0V to about +2.1V for the LM358 or to about 2.7V with the MC33171 with a single +3.3V supply.
A Charge-pump voltage-doubler IC can be used to supply the opamp with about 6.2V (they aren't perfect) so its max output voltage would be about 5.0V to 5.6V.
A Cmos opamp would have a max output voltage of 3.3V with a 3.3V supply and a high impedance load.

Hey thanks for the idea. My parthner and i finally figured out how to amplify the signal to the amount of voltage that we wanted. We used a pull up or pull down resistor to take care of the situation. The playstation signal for the attention was actually amplified when measuring it on the oscilloscope. The only problem was that the attention signal was the only signal so far that we were able to amplify using the pull up resistor. Sadly to say, the command signal didn't work the same way. There isn't much of a difference between the low and the high of the voltage. Then trying to use the pull up resistor method the HIGH would go up and the LOW would go up as well but not to want we wanted. THen, sometimes the LOW would go to were we wanted and then the HIGH would not be sufficient in terms of voltage. The reason why we were able to use a pull up resistor on the ATTENTION signal is because according to the playstation and how it works, the ATTENTION signal "GETS PULLED DOWN" when a transmission is going on and so this is when my partner thought of the idea behind using a pull up resistor. Now we were wondering if using a schmitt trigger would help with trying to seperate the difference in the HIGH and LOW of the command signal. When the Command signal is at 0V then the high would go to 200mV. This is not much of a difference. IS there any way of trying to pull that 200mV up using the schmitt trigger.

 

[Nigel Goodwin]

You really need to find out what's going on, the voltages you keep mentioning aren't logic levels (under any logic system) - I suspect you're probably measuring things incorrectly somehow?.

 

[Electrostatic]

You really need to find out what's going on, the voltages you keep mentioning aren't logic levels (under any logic system) - I suspect you're probably measuring things incorrectly somehow?.

My freind the HC12 microcontroller by motorola is a TTL type. Now accroding to the information i have gathered about this Microcontroller. The Logic 1 input voltage Vcc = min of 2.0 and Logic 0 input voltage Vcc = max 0.8

The program that my partner wrote for this microcontroller was to verify that the command 01H was receieved serially to the playstation controller from the Playstation as referenced in the method of operation. Now when my friend wrote the program the HC12 didn't want to respond to it because when the voltage levels measured coming out of the playstation did not meet the standard levels needed for the HC12. The voltages coming out of the playstation was the following:

DATA--------- .15V
ATTN---------- .32V
ACK----------3V
CMD-------- 243mV
CLK--------- 3.5V

The voltage levels im refering to is from the playstation. Im trying to match these voltage levels to the HC12's logic system of levels in order for the program to work.

 

[Nigel Goodwin]

The program that my partner wrote for this microcontroller was to verify that the command 01H was receieved serially to the playstation controller from the Playstation as referenced in the method of operation. Now when my friend wrote the program the HC12 didn't want to respond to it because when the voltage levels measured coming out of the playstation did not meet the standard levels needed for the HC12. The voltages coming out of the playstation was the following:

DATA--------- .15V
ATTN---------- .32V
ACK----------3V
CMD-------- 243mV
CLK--------- 3.5V

The voltage levels im refering to is from the playstation. Im trying to match these voltage levels to the HC12's logic system of levels in order for the program to work.

As I said above, those figures don't make any sense! - how were they measured?.

 

[Electrostatic]

The program that my partner wrote for this microcontroller was to verify that the command 01H was receieved serially to the playstation controller from the Playstation as referenced in the method of operation. Now when my friend wrote the program the HC12 didn't want to respond to it because when the voltage levels measured coming out of the playstation did not meet the standard levels needed for the HC12. The voltages coming out of the playstation was the following:

DATA--------- .15V
ATTN---------- .32V
ACK----------3V
CMD-------- 243mV
CLK--------- 3.5V

The voltage levels im refering to is from the playstation. Im trying to match these voltage levels to the HC12's logic system of levels in order for the program to work.

As I said above, those figures don't make any sense! - how were they measured?.

This information was taken from the oscilloscope. Each individual wire was taken and the voltage was measured by the scope. Why do you say that they may have been measured incorrectly.

 

[Nigel Goodwin]

The program that my partner wrote for this microcontroller was to verify that the command 01H was receieved serially to the playstation controller from the Playstation as referenced in the method of operation. Now when my friend wrote the program the HC12 didn't want to respond to it because when the voltage levels measured coming out of the playstation did not meet the standard levels needed for the HC12. The voltages coming out of the playstation was the following:

DATA--------- .15V
ATTN---------- .32V
ACK----------3V
CMD-------- 243mV
CLK--------- 3.5V

The voltage levels im refering to is from the playstation. Im trying to match these voltage levels to the HC12's logic system of levels in order for the program to work.

As I said above, those figures don't make any sense! - how were they measured?.

This information was taken from the oscilloscope. Each individual wire was taken and the voltage was measured by the scope. Why do you say that they may have been measured incorrectly.

Because they don't make any sense! - logic pins can be either HIGH or LOW, with LOW (usually!) being effectively 0V.

There are two values there (ACK and CLK) which look like logic HIGH levels, the other three 'could' be logic LOW levels - except that it would be completely pointless to list them?.

As you're using a scope you need to measure while there's some switching going on, and it's the logic HIGH you need to be looking at, but presumably it's just normal TTL type 5V logic?.

Amplifying the LOW level to make it high would result in it being permanently high - and you may as well use a piece of wire to connect it to Vdd if that's what you want?.

 

[i_build_stuff]

Are you sure those "high" logic levels are actually for "high" outputs?

With "Ack" and "Clk" hitting 3 and 3.5 volts (which are normal for logic circuits), could it be that the other outputs are either:

-actually staying low for some reason? (a reasonable pull up resistor has no effect on the level)

-in the "hi-z" state? (the voltage just goes to whatever you tie the pull up / down resistor to)

Chances are, there's some kind of handshaking that you need to do, and it expects you to send something down those lines. Almost all electronic devices that have two-way IO ports will start up in "receive" mode.

 

[Electrostatic]

So if the pin outs for the playstation are TTL voltage levels and the HC12 is a TTL controller then in other words there would be no need to try and amplify the signal coming from the playstation pin outs.

 

[Nigel Goodwin]

So if the pin outs for the playstation are TTL voltage levels and the HC12 is a TTL controller then in other words there would be no need to try and amplify the signal coming from the playstation pin outs.

Exactly! - like I said, the voltages you gave make no sense at all - you need to check them with a scope, and make sure you get values for both HIGH and LOW levels (then throw the low one away!).

 

[Electrostatic]

So if the pin outs for the playstation are TTL voltage levels and the HC12 is a TTL controller then in other words there would be no need to try and amplify the signal coming from the playstation pin outs.

Exactly! - like I said, the voltages you gave make no sense at all - you need to check them with a scope, and make sure you get values for both HIGH and LOW levels (then throw the low one away!).

Hey Nigel Question... Is there a certain IC out there that can do multiplexing? What im planning on doing is taking the remote control and splitting it into two different functioning parts.

 

[Nigel Goodwin]

A specific IC would only be good for the specific purpose it was designed, there 'may' be something available, but we would need to know EXACTLY, and I mean EXACTLY! what you are trying to do.

I don't see much relevence between multiplexing and your controller?.

 

[Electrostatic]

A specific IC would only be good for the specific purpose it was designed, there 'may' be something available, but we would need to know EXACTLY, and I mean EXACTLY! what you are trying to do.

I don't see much relevence between multiplexing and your controller?.

Im trying to recreate the playstation controller into two separate gloves using pressure sensors for both of the gloves. In other words one hand will do the directional section and the other hand will do the buttons. So, the controller is being split in half but i trying to think of a way in which to combine the two separate gloves to form one data line.

 

[Nigel Goodwin]

A specific IC would only be good for the specific purpose it was designed, there 'may' be something available, but we would need to know EXACTLY, and I mean EXACTLY! what you are trying to do.

I don't see much relevence between multiplexing and your controller?.

Im trying to recreate the playstation controller into two separate gloves using pressure sensors for both of the gloves. In other words one hand will do the directional section and the other hand will do the buttons. So, the controller is being split in half but i trying to think of a way in which to combine the two separate gloves to form one data line.

As I suggested above, multiplexing isn't what you want!.

You just do as the existing controller presumably does?, have the sensors feeding one micro-controller, which sends one data stream.

Do you know all the protocols used by the original controller?, you're going to have to know them to make your own from scratch!.