High Speed Hipot

The High speed hipot option allows multiple nets to be tested simultaneously, increasing the speed of the test. This is an attractive option if you have long test times. However, there are some important notes about using the High Speed Hipot option. 

  • High Speed Hipot option should not be used with highly capacitive devices. Because the high speed mode will charge multiple nets at the same time it can cause false failures in highly capacitive devices.
  • If the high speed mode detects a failure it will drop back into normal hipot mode to determine exactly which net is failing. This means that if your device has a high number of high voltage failures the high speed mode could actually take longer due to constant switching between the high speed and normal modes. It also means that if the high voltage failure is not repeatable it may only be caught in high speed mode and not when switched back to normal mode. In this case the tester would be unable to provide information on exactly which net failed. 

The charts below demonstrate the difference between normal mode and high speed mode. In the example below high speed mode uses half as many test cycles. This is a significant savings, but as the number of nets in the test increase, this time savings is even more significant. For example - a device with 128 nets would require 128 test cycles in normal mode, but only 8 cycles in high speed mode - a 16x speed increase.  

Normal Mode

   

CYCLE

   

1

2

3

4

5

6

7

8

N
E
T

1

HV

GND

GND

GND

GND

GND

GND

GND

2

GND

HV

GND

GND

GND

GND

GND

GND

3

GND

GND

HV

GND

GND

GND

GND

GND

4

GND

GND

GND

HV

GND

GND

GND

GND

5

GND

GND

GND

GND

HV

GND

GND

GND

6

GND

GND

GND

GND

GND

HV

GND

GND

7

GND

GND

GND

GND

GND

GND

HV

GND

8

GND

GND

GND

GND

GND

GND

GND

HV

High Speed Mode

High speed hipot uses a heap sort method. With this method, a group of nets is charged and compared against a group of nets at ground. Note that half of the cycles are used for the same number of nets.

   

CYCLE

   

1

2

3

4

N
E
T

1

HV

HV

HV

GND

2

HV

HV

GND

HV

3

HV

GND

HV

GND

4

HV

GND

GND

HV

5

GND

HV

HV

GND

6

GND

HV

GND

HV

7

GND

GND

HV

GND

8

GND

GND

GND

HV