What is the maximum current I can force into the digital potentiometer?

The maximum current is limited by 2 boundaries at a given resistance setting.

1- Terminal voltage range limit

Its the dominant in most settings, in this case the voltage generates by the current and the selected resistance value cannot exceed the supply rails.

ie- Imax = Vdd / RWB

RWB = 5k

Vdd = 5V

Imax = 5V/5k = 1mA

2- Maximum current handling capabilities.

When the part is used in rheostat mode, at lower resistance values, the current is limited by the maximum current density.

This limitations depends on the frequency:

DC = maximum current density

AC (f > 10kHz) = maximum current density / pulse duty factor

AC (f < 10kHz) = maximum current density / sqrt (pulse duty factor)

ie. maximum current density = 3mA

signal frequency = 2kHz

duty = 50%

Imax = 3mA / sqrt(0.5) = 4.2mA

Typically data sheets include a Imax vs. Code graphs for DC current.

The maximum current is limited by 2 boundaries at a given resistance setting.

1- Terminal voltage range limit

Its the dominant in most settings, in this case the voltage generates by the current and the selected resistance value cannot exceed the supply rails.

ie- Imax = Vdd / RWB

RWB = 5k

Vdd = 5V

Imax = 5V/5k = 1mA

2- Maximum current handling capabilities.

When the part is used in rheostat mode, at lower resistance values, the current is limited by the maximum current density.

This limitations depends on the frequency:

DC = maximum current density

AC (f > 10kHz) = maximum current density / pulse duty factor

AC (f < 10kHz) = maximum current density / sqrt (pulse duty factor)

ie. maximum current density = 3mA

signal frequency = 2kHz

duty = 50%

Imax = 3mA / sqrt(0.5) = 4.2mA

Typically data sheets include a Imax vs. Code graphs for DC current.