EasyTK1_IO Jetson TK1 voltage level performance test

Before the test of EasyTK1_IO on Jetson TK1 I prefered to do a instrumental test of Jetson TK1 voltage level adapter ( EasyTK1_IO ) to analize & solve potentially-destructive problem.

Test equipmen

To do the test I’ve used this test equipment:

  • AFG3022B Tektronix Dual Channel Arbitrary Function Generator

    AFG3022B Tektronix Dual Channel Arbitrary Function Generator

    AFG3022B Tektronix Dual Channel Arbitrary Function Generator

  • RIGOL DS1074Z 4 Channel 70Mhz Oscilloscope

    RIGOL DS1074Z 4 Channel 70Mhz Oscilloscope

    RIGOL DS1074Z 4 Channel 70Mhz Oscilloscope

Part of EasyTK1_IO scheme under test

this is the parto of EasyTK1_IO, Jetson TK1 voltage level shifter, scheme under test. On left side you can see LowVoltage side signal, this is Jetson TK1 side. On right you can see the “HighVoltage” signal side, this is device side. V_PUo-3 lave is power supply input from external device and can be 1,8V to 5V

BSS138 Voltage level circuit

Part of EasyTK1_IO scheme under test

Test Setup of EasyTK1_IO voltage level shifter

I’ve soldered on EasyTK1_IO minimum required components only, voltage-level component of some channel essentially.

I’ve connected 2 channel of  my oscilloscope and output of signal generator as figure:

EasyTK1_IO setup

EasyTK1_IO setup


EasyTK1_IO measure report

In this image I’ve tested HighVoltage  to LowVoltage trasmission without power supply. Output signal is below 1,8V acceptable on Jetson TK1:

EasyTK1_IO_test_1

In this table I’ve summarized some test with different frequency and voltage:

Frequency Direction
of test
Report 1 Report 2 Report 3
 1Mhz from 3,3V

to 1,8V

EasyTK1_IO_test_3
EasyTK1_IO_test_4
EasyTK1_IO_test_5
EasyTK1_IO_test_6
EasyTK1_IO_test_7
1Mhz from 1,8V

to 3,3V

EasyTK1_IO_test_8
500Khz from 1,8V

to 3,3V

EasyTK1_IO_test_9  

 

 150Khz from 1,8V

to 3,3V

EasyTK1_IO_test_11 EasyTK1_IO_test_12
 100Khz from 1,8V

to 3,3V

EasyTK1_IO_test_10
 1Mhz from 3,3

to 1,8V

EasyTK1_IO_test_13 EasyTK1_IO_test_14 EasyTK1_IO_test_15
 500Khz from 3,3

to 5V

EasyTK1_IO_test_16 EasyTK1_IO_test_17
 150Khz  from 3,3

to 5V

EasyTK1_IO_test_18 EasyTK1_IO_test_19 EasyTK1_IO_test_20
150Khz  from 1,8

to 5V

EasyTK1_IO_test_21 EasyTK1_IO_test_22 EasyTK1_IO_test_23




Conclusion about EasyTK1_IO

Jetson TK1 is safe but 10K ohm pullup resistor can be a limit in High frequency operation. I can reduce this pull-up resistor but in different devices, like I2C device, there are pull-up resistor, they will reduce effective pull-up increasing frequency performance.