Datasheet

Input

Steady-State

Output Magnitude

RATED_VOLTAGE[7:0]

½ RATED_VOLTAGE[7:0]

Full Braking

PWM

Input Interface

0% 50% 100%

0x00

Closed Loop, BIDIR_INPUT = 0

0x7F 0xFF

RTP (8-bit) DATA_FORMAT_RTP = 1

DRV2605

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SLOS825C –DECEMBER 2012–REVISED SEPTEMBER 2014

Programming (continued)

7.5.8.1.2 Closed-Loop Mode, Unidirectional

In closed-loop unidirectional mode, the DRV2605 device provides automatic overdrive and braking for both ERM

and LRA devices. This mode is the most easy mode to use and understand. This mode uses the full 8-bit

resolution of the driver. Closed-loop unidirectional mode offers the best performance; however, the data format is

not physically compatible with the open-loop mode data that may be used in some existing systems

The reference level for steady-state full-scale drive is set by the RATED_VOLTAGE[7:0] bit (when auto-

calibration is performed). The output voltage can momentarily exceed the rated voltage for automatic overdrive

and braking, but does not exceed the OD_CLAMP[7:0] voltage. Braking occurs automatically based on the input

signal when the back-EMF feedback determines that braking is necessary.

Because the system is unidirectional in this mode, only unsigned data should be used. The RTP mode has 8 bits

of resolution over the I

C bus. Setting the DATA_FORMAT_RTP bit to 0 (signed) is not recommended for this

mode.

Figure 25.

NOTE

The TS2200 library data is stored in bidirectional format and cannot be used in

unidirectional mode.

For the RTP interface, set the DATA_FORMAT_RTP bit to 1 (unsigned).

Product Folder Links: DRV2605