controller Charge Pump?

[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