LSF0102: LSF0102 PU recommendation

Anthony Lee2

Part Number: LSF0102
Other Parts Discussed in Thread: TXB0104,

We want to change the level shifter IC from TXB0104 to LSF0102 for one port.We found we can't find the good value for external pull up resistor .

Could you help to porvide the recommend or calculation form?

A side: 1.8V

B side: 3.3V

A side PU	B side PU	device PU(B side)	device side waveform
220 ohm	1k ohm	8.2k ohm	High 2.4~3.3V Low 820mV
220 ohm	1.5k ohm	8.2k ohm	High 2.4~3.3V Low 620mV
150 ohm	1.5k ohm	8.2k ohm	High 2.3~3.3V Low 440mV
100 ohm	1.5k ohm	8.2k ohm	High 2.4~3.2V Low 400mV
100 ohm	1.3k ohm	8.2k ohm	High 2.3~3.2V Low 400mV
100 ohm	820 ohm	8.2k ohm	High 2.5~3.2V Low 540mV
100 ohm	200 ohm	8.2k ohm	High 3.3V Low 1.5V
100 ohm	4.7k ohm	8.2k ohm	High 2.2 ~ 3.2V Low 220mV
1k ohm	4.7k ohm	8.2k ohm	High 2.8 ~ 3.2V Low 960mV
1.5k ohm	4.7k ohm	8.2k ohm	High 2.8 ~ 3.2V Low 960mV
4.7k ohm	4.7k ohm	8.2k ohm	High 2.2 ~ 3.2V Low 2.2V
4.7k ohm	8.2k ohm	8.2k ohm	High 2.1 ~ 3.2V Low 2.1V
1k ohm	8.2k ohm	8.2k ohm	High 2.6 ~ 3.2V Low 500mV
1k ohm	6.2k ohm	8.2k ohm	High 2.7 ~ 3.2V Low 840mV
100 ohm	300 ohm	8.2k ohm	High 3~3.3V Low 1.2V
100 ohm	390 ohm	8.2k ohm	High 3~3.3V Low 1V
470 ohm	1k ohm	8.2k ohm	High 3~3.3V Low 1.2V

over 6 years ago

0 Gabriel Lake1 over 6 years ago

TI__Expert 3450 points

Hi Anthony,

Pull up resistor values for LSF devices depend on the desired drive strength and output voltage levels. The LSF family application report contains details on choosing and placing PU resistor values, and a table of example values can be found in the data sheet.

regards,

Gabriel

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LSF0102: LSF0102 PU recommendation