AN2836 datasheet(28/57 Pages) STMICROELECTRONICS

Part #	AN2836

Description	Modern motion control applications need more flexibility that can be addressed

PDF	57 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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28 / 57 page

Designing an application with L6225, L6226, L6227

AN2836

28/57

Doc ID 15084 Rev 1

Figure 27.

Output current detection threshold versus RCL value (L6226 only)

The overcurrent detection threshold can also be adjusted through an external reference

voltage, as shown in Figure 28. The external reference voltage source should be able to sink

current (about 300 µA maximum). Moreover, if the supply voltage is provided to the L6226

before VEXT, and its EN pins are at a high logic level, the device starts working with minimum

OCD threshold (actually the capacitor placed at the bottom of RCL allows a short startup

time with a higher OCD threshold). VEXT can also be obtained through a PWM output of a

µC, adding a series resistor to obtain a low-pass filter.

The OCD threshold (ISOVER) follows the equation:

●

ISOVER =

±10%, at -25 °C < Tj < 125 °C if 0.25 A < ISOVER < 2.25 A

Figure 28.

Adjusting the OCD threshold through an external reference voltage

(L6226 only)

9208.3 1.2V

Vext

–

()

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AN2836 Datasheet(PDF) 28 Page - STMicroelectronics