controller Charge Pump?

[Luciano]

Hi,

Feel free to "bite" the BOSCH design.
(See the block diagram of the IC CJ110).

But, doesn't it look familiar somehow?

Luciano

* * *

CJ110 - Lambda Probe Sensing IC for LSU4.
http://www.semiconductors.bosch.de/p...y_extended.pdf


CJ120 - Lambda Probe Sensing IC for LSU4.x
Ri Measurement; SPI-Interface; Diagnostics
http://www.semiconductors.bosch.de/p...y_extended.pdf


Source:
http://www.semiconductors.bosch.de/e...ine/engine.asp

* * *
Bosch LSU 4.2 Planar Wide Band Lambda Sensor:
http://wbo2.com/lsu/Y258K01005e03mar21eng.pdf

* * *

[toalan]

humm, I was gonna do the design myself without the BOSCH IC, I was looking around for vendors of the BOSCH IC and never found any.

[Luciano]

Europe

http://www.semiconductors.bosch.de/e...tributoren.asp
http://www.rutronik.com/english/index.html
http://www.rutronik.com/produktderwo...kw09/index.php

The CJ110 and CJ120 are on this list:
http://www.rutronik.com/download.php...osch-Flyer.pdf


USA

http://www.bosch.us/content/language1/html/1284.htm

Robert Bosch Corp.
38000 Hills Tech Drive
Farmington Hills, MI 48331
By telephone: 248-553-9000
By fax: 248-553-1426

[toalan]

TY for the info.

[Luciano]

Hi,

Print the page 3 and 4 of the CJ120 PDF.
(The Block diagram page and the Application circuit page).

http://www.semiconductors.bosch.de/p...y_extended.pdf

Add to the application circuit the two op-amp's and connect them
as they are depicted on the block diagram page.
(Draw that with a pencil inside the CJ120 on page 4).


The two op-amp's:
Pumpstrom-Regler = Pump current control
Pumpstrom-Meßverstärker = Pump current sense amplifier


Voltages:

==============================================
PIN Vcc = +5 V
==============================================
PIN VM = +2.5 V (Virtual ground voltage source)
(0.5 x VCC)
==============================================
PIN US = +2.95 V (Nernst cell reference voltage source)
(450mV, reference to virtual ground)
===============================================
PIN GND = 0 V
================================================

The two op-amp's have a single polarity supply.
(+5 and GND).

On the output of the op-amp "Pump current control"
you will need a 100 ohm resistor.


* * *

The idea is to replicate what Bosch is doing inside the CJ120.

You will need a way to simulate the LSU4 during the testing of the circuit.
(DC +/- milliampere meter and a voltage that goes from 4.0V down to 2.5).

Do you understand how it works?

Luciano

[toalan]

I have not seen the additions you have made on the PDF because the current computer I use gives an error with the file, I will look at it later on a nother computer.

I pretty much understand how the circuits works. I have made a citcuit long time ago that was very similar to what the Bosch ICs are doing. That was with analog circuits right now I am trying to do most of the Analog stuff using a MCU so to minimize tolerance problems and to cheapen things up and also to add dataloggin capabilities to it.

I built my first circuits based on the Bosch Datasheet for the Sensor itself because I never knew the Datasheets for the ICs existed publicly. The circuit I built before knowledge of the Cj120 datsheet was similar in many ways to the CJ120 but more simplier. Now that I seen the CJ120 the only thing I can not understand is on Page 3 or 4 of the CJ120 PDF, the use of Rical (82 ohms). The fact that I can not speak German only adds to the problem. But I am sure somewhere in my subconcious my mind is solving the issue, so it will only be a matter of time before I know what the RiCal does. I suspect it maybe a reference restance that the resistor in the pump Cell (Ri) should be at during normal operations. The reason I say this is becasue I know pretty sure that the Pump resistance should be close to 80 ohms during normal operation and not the 100 ohms that is shown on the diagram.

There is no need to simulate the BOSCH LSU sensor in my testing since I have about 4 of them lying around. Also the Pump current goes through an external 61.9 resistor, I suspect the 100 ohms you are talking bout is the internal resistance of the pump cell.


I would love to by the bosch ICs from rutronik but they require huge quantity purchases something in the thousands per order.

If I can digitize most of the analog circutry I can make a very cheap, fast and accurate Wideband reader.

[toalan]

BTW Luciano TY very very much for posting up the documents, because of the new information I found in there I am going to make a few design adjustments to my circuits and MCU program.