What are buses?
Buses are the pathways that create the connection between a drive resource and a pin in the switch matrix. The number of buses allows multiple drive types and settings to be available to the switch matrix and the DUT.
In electrical terminology, a bus is a conductor in which signals travel both ways. In curve tracing, we source and sense the signal through the buses. Bus configurations determine the applications of the curve tracer. However, your device’s pin count will determine the curve trace model.
Our automatic curve tracers come in a range of configurations that can be scaled to meet your needs. They scale in two directions; pin count and the number of buses.
To make your decision, most users only need to answer a couple of questions:
- What is the largest device you plan to test in your lab?
- Do you want to be able to power up the device to measure IDD or curves in the powered state?
- If so, how many voltages will your device need to power up?
The pin count you need ultimately determines the curve tracer. See below for common configurations.
For the MT Century, 100 pins are the standard pin count. The MT Century uses a cable set with a 100-pin connector which is compatible with many low pin DUT boards. We developed the 950 series fixture with Mini and Extended Mini cards as the primary fixture for the MT Century. Dedicated R1 or R4 DUT boards can replace the 950 series but limits test abilities to your specified applications.
The MultiTrace has a flexible and wide range of pin counts:
The MegaTrace supports larger pin counts:
Our curve tracers share the same internal architecture and are available with 2, 4 or 6 bus configurations across the full range of pin count available. Within a curve tracer, each pair of buses is integrated with a common set of drives. Increasing the number of drives will increase the number of buses.
Below is a diagram of the 2 Bus configuration with connections to pins, cards, and fixture box.
Curve Tracer Configurations
What are drives?
Drives are what we call the power supplies that do all the work.
All drives in our curve tracers are 4 quadrant Source Measure Units (SMU), meaning they can source or measure positive and negative voltages and currents.
The drives have multiple operating modes that allow use as a current source, voltage source or curve tracer source, and are programmable to the full resolution of 16-bit A/D and D/A channels.
Most drives have a range of +/-15V and +/-1A. But some drives have a range of +/-100V and +/-100mA.
Current measurement accuracy depends on settings, especially the series resistor selection. Measurements as low as 1nA are possible on most drives.
Whether a drive is connected to a switch matrix input or not depends on the bus configuration:
- 2 bus configurations have 4 SMU Drives
- 4 and 6 bus configurations have 8 SMU Drives (chart of specs below)
|Drive Type||Spec||Ranges||2 bus||4 bus||6 bus|
|Precision drive||+/-15V and +/-1A||8 series resistors||2||1||1|
|Power Drive||+/-15V and +/-1A||1 series resistor||1||2||2|
|High Voltage drive||+/-100V and +/-100mA.||5 series resistors||1||2||2|
Contact us for detailed technical specs.