Spindle Logic Interface Specifications

The digital interface to the controller chip has the following specifications:

Parameter

Min.

Max.

Units

V

0.5

V

V

0.2Vcc

V

EMF_Det Hysteresis

V

-1

µA

1

µA

EMF_Det Load

30pF, 1.6mA

The SP_CLK is a CMOS output. The EMF_Det input is a schimitt trigger with the specified thresholds

and leakage currents.

Vpwr Blocking Diode

The blocking diode in the Vpwr line is optionally a non-schottky part. If this occurs, schottkys should be

used in the charge pump to provide the proper voltage at minimum supply. If regular diodes are used in

both places, the part is functional (at 10% increased Rdson in all drivers) at the lowered Vpwr voltage.

Figure 9a. Run Mode Spindle Voltage Waveforms

Figure 9b. Start Mode Spindle Voltage Waveforms

L6256

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