DRV411EVM Datasheet, PDF (4/13 Pages) Texas Instruments – DRV411EVM Users Guide

EVM Operation
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3.2 Gain Setting and Compensation Frequency
The DRV411EVM provides two jumpers to configure the gain and sensor excitation frequency selection.
The gain selection input pins are pulled to ground, or logic ‘0’ by default (jumpers ‘open’). Closing the
jumpers places the associated GSEL pin at the applied Vcc potential (logic ‘1’). Table 4 provides a
description of the available options:
Mode
Gain_1
Gain_2
Gain_3
External Gain /
Compensation
Table 4. Gain and Compensation Frequency Settings
GSEL1
Open
Open
Closed
Closed
GSEL2
Open
Closed
Open
Closed
Description
G = 250 V/V, Compensation frequency set to 3.8 kHz
G = 250 V/V, Compensation frequency set to 7.2 kHz
G = 1000 V/V, Compensation frequency set to 3.8 kHz
Excitation/chopping circuitry switched off. The gain and compensation is set by using
external resistors and capacitors (R3/C3 and R4/C4).
4 EVM Operation
There are four pin sockets on the left side of the EVM for mounting the user-supplied Hall-sensor. Besides
indium antimonide (InSb) Hall elements, the DRV411 can also be connected to symmetrical gallium
arsenide (GaAs) Hall elements such as the HG-302C from AKM Semiconductor.
With a Hall sensor mounted to the DRV411, the user is then free to mount their compensation coil to the
‘drilling area’ noted on the EVM. The area inside the silkscreen is free of any copper and can be used as
needed to provide a means of securing the coil to the EVM. Connectors J1 and J2 are provided to
terminate the compensation coil. Pins 1 and 2 of both J1 and J2 are connected together and then back to
the ICOMP and IAIN pins of the DRV411 (please refer to the DRV411EVM Schematic, for details). The
coil can be terminated at either the J1 or the J2 location, or between J1 and J2, if necessary.
Once the sensor and compensation coil are mounted to the EVM, apply a current limited (50 mA max)
5-V DC source to the banana jacks or test points labeled VCC and GND. The current to be monitored by
the DRV411 can then be applied through the compensation coil primary winding.
5 DRV411EVM Schematic and Bill of Materials
Section 5.1 contains the schematic for this EVM and Section 5.2 presents the BOM for this EVM.
5.1 DRV411EVM Schematic
Figure 2 illustrates the EVM schematic.
4
DRV411EVM User's Guide
SLVU772A – August 2013 – Revised November 2013
Copyright © 2013, Texas Instruments Incorporated
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