Developing a current measurement module that is fast, that has a high resolution and provides highly repeatable measurement results is not an easy nor trivial task.
A quiescent (supply or ground) current (IDDQ, ICCQ, ISSQ) measurement module should be able to handle the (large) transient currents - with potential peak values of several hundreds of milli-amps, several amps or even tens of amps, which occur when the circuit is switching from one state to another - as well as accurately measuring the quiescent currents with normal values in the nA-ľA- mA range, all without affecting at any time the operation and the operation conditions of the circuit under test.
IXXQ measurement modules can be realized either as on-chip measurement / observation circuitry (monitor) - in that case they are integrated together with the circuit to test and are called Built-in Current Monitors (BIC) - or they can be realized as a dedicated measurement module, which eventually can be mounted on the interface board that connects the device under test with the test equipment - in such a case these circuits are called Off-Chip Current Monitors (OCM) and they can be realized using discrete components or as an integrated circuit themselves - or they can be can be realized as an option to an ATE machine.
Ridgetop Europe is committed to provide the best in class Q-Star current measurement products and solutions, addressing the varies aspects of current measurements and supporting both quiescent as well as dynamic current measurement and current measurement based test strategies. The Q-Star add-on solutions typically can make measurements 100 to 1000 times faster than embedded ATE solutions, are able to drive high capacitive loads and have a measurement resolution / repeatability which is typically an order of magnitude better than the embedded ATE measurement solutions. These characteristics support the use and application of current testing for an efficient and reliable screening of devices, even in the presence of large background currents.