Curve Trace, Bus, & System Configurations

We build our automatic curve tracers in a wide range of configurations to meet your test and device 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:

1. What is the largest device you plan to test in your lab?
2. Do you want to be able to power up the device to measure IDD or curves in the powered state?
   1. If so, how many voltages will your device need to power up?

But, the pin count you need ultimately determines the curve tracer. See below for common configurations.

Overview of Curve Trace Model Configurations

MT Century 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 with Mini and Extended Mini cards as the primary test fixture for the MT Century. However, dedicated R1 or R4 DUT boards can replace the 950 Series, but limits test abilities to your specified applications.

MultiTrace Configurations

The MultiTrace has a flexible and wide range of pin counts: 216, 324, 432, 625, 1152. Configurations with 216 through 625 pin counts use the PGA-625 fixture box with an array configured to the pin count. 1152 pin count uses an octopogo fixture box with an octopogo interface.

MegaTrace Configurations

The MegaTrace supports larger pin count devices with the most popular configurations being 1080 and 2160 pins. 1,080 pins are available on the MegaTrace with two options of interfaces: the Octopogo or a Large Breakout Board. The MegaTrace is commonly configured with the Octopogo. 2,160 pins are available only with the Large Breakout Board. This configuration is the largest curve tracer RTI has to offer.

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.

Bus Configurations

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. When you increase the number of drives, the number of buses will also increase.

2 buses are paired with 4 SMU supplies we call drives. Two precision drives are connected to the switch matrix input and your device is connected to the output. Pins can be grounded, or curve traced. The primary application for this configuration is Unpowered Curve Tracing, but other custom setups are possible. Contact us to discuss customization.

4 buses are paired with 8 SMU supplies we call drives. This allows the connection of power and ground, plus one logic level and a power source. This setup is capable of powered curve tracing, IDD measurements as well as unpowered curve tracing, but is limited to a single VDD voltage.

6 buses are paired with 8 SMU supplies we call drives. This allows the connection of power and ground, plus one logic level and a power source. This setup is capable of powered curve tracing, IDD measurements as well as unpowered curve tracing, but is limited to two or four VDD voltages.

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 also 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.

Drive Types

Most drives have a range of +/-15V and +/-1A. However, 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 & 6 bus configurations have 8 SMU Drives (chart of specs below)