TPS62097: Mode pin current(MODE=L)

Kuramochi Tadahiko

Guru 28715 points

Part Number: TPS62097

Hi,

What ampere is current source of mode pin during MODE=Low?

I would like to know maximum resistance to pull-down mode pin under 0.4V.

Best Regards,

Kuramochi

over 6 years ago

0 Alfonso Furio over 6 years ago

TI__Expert 3645 points

Hello,

sorry but to pull this pin down you should connect to AGND, no resistor needed.

0 Kuramochi Tadahiko over 6 years ago in reply to Alfonso Furio

Guru 28715 points

Hi,

Mode pin can't be connected with AGND directly because I controll MODE pin by MCU.

Is the current of MODE pin uA order?

Best Regards,

Kuramochi

0 Alfonso Furio over 6 years ago in reply to Kuramochi Tadahiko

TI__Expert 3645 points

Hello,
This use of the MODE pin is not recommended in our D/S, please refers to section 6 (page 3) of the D/S to see the MODE selection. Anyway, in the D/S in section 7.5 (page 5), you can find the information related to the leakage current of the MODE pin (when is High) and in section 7.1 (page 4) the absolute maximum ratings in terms of voltage. These are the only parameters that are available for the MODE pin.

0 Kuramochi Tadahiko over 6 years ago in reply to Alfonso Furio

Guru 28715 points

Alfonso-san,

I would like to control such below on the datasheet.

In this case, mode pin must be pulled low during mode detection.

Then, what resistance should we set pull down resistor.

Actually, this resistor is included in the MCU.

Best Regards,

Kuramochi

0 Alfonso Furio over 6 years ago in reply to Kuramochi Tadahiko

TI__Expert 3645 points

Hello,
To pull low the Mode pin, you can refer to VL_MO in section 7.5 of the D/S. The low-level input voltage of the Mode pin should be lower than 0.4V. I can't give a specific value for the resistor because it is dependant on how the GPIO is implemented, its leakage current and which resistor is available.

0 Kuramochi Tadahiko over 6 years ago in reply to Alfonso Furio

Guru 28715 points

Hi,

I think that VL_MO is not appropriate because mode pin has current source that push current during MODE detection.

VL_MO is "pull in" direction against above current source.

Please confirm source current value because my customer can't design without this information.

Best Regards,

Kuramochi

0 Alfonso Furio over 6 years ago in reply to Kuramochi Tadahiko

TI__Expert 3645 points

Hello,

The nominal value in our characterization is 20uA, but you have to be aware that it isn't a spec reported in our D/S. A higher value of current can be sunk, but it depends on the driver capability of your uC output buffer (GPIO).

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TPS62097: Mode pin current(MODE=L)