DRV8461SPWPR datasheet(35/117 Pages) TI

35 / 117 page

Table 7-20. OFF Time Settings

SPI Interface

H/W Interface

OFF Time

TOFF

00b

9 µs

01b (default)

19 µs

10b

Hi-Z

27 µs

11b

330kΩ to GND

35 µs

7.3.9.6 Current Regulation Blanking Time and Deglitch Time

After the start of drive phase in an H-bridge, the current sense comparator is ignored for a period of time

(blanking time) before enabling the current-sense circuitry. The blanking time also sets the minimum drive time of

the PWM.

• When the device operates with hardware interface, the blanking time is fixed at 1.5 μs.

• When the device is operating with SPI interface, the blanking time can be programmed by the TBLANK_TIME

bits as shown in Table 7-21, with a default value of 1.5 μs.

Table 7-21. TBLANK_TIME Settings

TBLANK_TIME

Blanking Time

00b

1 μs

01b (default)

1.5 μs

10b

2 μs

11b

2.5 μs

When the current is close to the ITRIP level, a 0.5 μs deglitch time ensures proper current regulation.

7.3.10 Current Sensing with External Resistor

PWM current regulation is based on the voltage sensed across the internal sense resistor of the DRV8461.

Optional external resistors can be placed between the PGND pins and system ground (or in series with the VM

pins) to sense the coil current, as shown in Figure 7-16. The DRV8461 has two PGNDA pins and two PGNDB

pins - one pair for each H-bridge. So, the current of each stepper motor coil can be sensed separately by placing

sense resistors between PGND pins and system ground. All the four VM pins are shorted internally - so if a

sense resistor is placed in the VM path, it will sense the combined current of both the H-bridges.

The voltage drop across the external sense resistor connected between PGND pins and system ground should

not exceed 300 mV. The sensed coil current can be processed to monitor motor health, or used to generate

necessary signals in a field-oriented-control loop to improve overall system efficiency.

www.ti.com

DRV8461

SLOSE98 – DECEMBER 2022

Submit Document Feedback

Product Folder Links: DRV8461

DRV8461SPWPR Datasheet(PDF) 35 Page - Texas Instruments

DRV8461SPWPR Datasheet(HTML) 35 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL