DRV8307_15 Datasheet, PDF (20/34 Pages) Texas Instruments – DRV8307 Brushless DC Motor Controller

DRV8307
SLVSCK2 – APRIL 2014
www.ti.com
9 Application and Implementation
9.1 Application Information
9.1.1 Hall Sensor Configurations and Connections
The Hall sensor inputs on the DRV8307 device are capable of interfacing with a variety of Hall sensors.
Typically, a Hall element is used, which outputs a differential signal on the order of 100 mV. To use this type of
sensor, the VREG regulator can be used to power the Hall sensor. Figure 11 shows the connections.
VREG
INP
OUTN Hall _OUTP
Sensor
Optional
Hx+
+⁺
Hall
INN
Hx±
Amp
±^-
Figure 11. Differential Hall Sensor Connections
Since the amplitude of the Hall sensor output signal is very low, often capacitors are placed across the Hall
inputs to help reject noise coupled from the motor PWM. Typically capacitors from 1 to 10 nF are used.
Some motors use digital Hall sensors with open-drain outputs. These sensors can also be used with the
DRV8307 device, with the addition of a few resistors (see Figure 12).
All Resistors 1 to 4.7 k
VREG
VCC
Hall
Sensor
GND
OUT
To Other
Hx± Inputs
Hx+
+⁺
Hall
Hx±
Amp
-_±
Figure 12. Single-Ended Hall Sensor Connections
The negative (Hx–) inputs are biased to 2.5 V by a pair of resistors between VREG and ground. For open-
collector Hall sensors, an additional pullup resistor to VREG is needed on the positive (Hx+) input.
9.1.2 ENABLEn Considerations
Because the ENABLEn function doubles as a sleep (low-power shutdown) function, there are some important
considerations when asserting and deasserting ENABLEn.
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