Datasheet
Table Of Contents
- FEATURES
- APPLICATIONS
- DESCRIPTION
- PINOUT INFORMATION
- ABSOLUTE MAXIMUM RATINGS
- THERMAL INFORMATION
- RECOMMENDED OPERATING CONDITIONS
- ELECTRICAL CHARACTERISTICS
- TIMING REQUIREMENTS
- TYPICAL CHARACTERISTICS
- SYSTEM DIAGRAMS
- APPLICATION INFORMATION
- ECCENTRIC ROTATING MASS MOTORS (ERM)
- LINEAR RESONANCE ACTUATORS (LRA)
- AUTO-RESONANCE ENGINE FOR LRA
- OPEN LOOP OPERATION FOR LRA
- SMART LOOP ARCHITECTURE
- AUTO CALIBRATION
- WAVEFORM LIBRARIES
- WAVEFORM SEQUENCER
- LIBRARY PARAMETERIZATION
- REAL-TIME PLAYBACK (RTP) MODE
- MULTI-MODE INPUT PIN (IN/TRIG)
- DEVICE ENABLE
- CONSTANT VIBRATION STRENGTH
- EDGE RATE CONTROL
- CAPACITOR SELECTION
- MODES OF OPERATION
- BLOCK DIAGRAM
- GENERAL I2C OPERATION
- SINGLE-BYTE AND MULTIPLE-BYTE TRANSFERS
- SINGLE-BYTE WRITE
- MULTIPLE-BYTE WRITE AND INCREMENTAL MULTIPLE-BYTE WRITE
- SINGLE-BYTE READ
- MULTIPLE-BYTE READ
- REGISTER MAP
- DEVICE PROGRAMMING
- WAVEFORM LIBRARY EFFECTS LIST
- PCB LAYOUT RECOMMENDATIONS
- Revision History
( )
RMS PEAK LRA
V V 1 800 s f= - m
PEAK
5.44V
V ODClamp[7 : 0]
255
=
AVG PEAK
(DriveTime - 300 s)
V V
DriveTime IDissTime BlankingTime
m
=
+ +
PEAK
5.44 V
V ODClamp[7 : 0]
255
=
OD
5.6 V
V ODClamp[7 : 0]
255
=
DRV2605
SLOS825B –DECEMBER 2012–REVISED JANUARY 2014
www.ti.com
PROGRAMMING THE OVERDRIVE CLAMP VOLTAGE
During closed loop operation, the actuator feedback lets the output voltage go above the rated voltage during the
automatic overdrive and automatic braking periods. The ODClamp[7:0] value (Register 0x17) sets a clamp so
that the automatic overdrive is bounded. This also serves as the full scale reference voltage for open loop
operation. The ODClamp[7:0] value always represents the peak voltage that is allowed, regardless of the mode.
Note that if the supply voltage (VDD) is less than the overdrive clamp voltage, the output driver will not be able to
reach the clamp voltage value because the output voltage cannot exceed the supply voltage. Also note that if the
rated voltage exceeds the overdrive clamp voltage, the overdrive clamp voltage will supercede.
LRA Mode (Closed Loop) and ERM Mode (Open Loop)
Equation 4 is the peak voltage allowed during all modes of operation.
(4)
ERM Mode (Closed Loop)
Although Equation 5 gives the peak voltage for the overdrive clamp, it is desirable in ERM mode to know the
average voltage obtained when clamped. The closed loop mode periodically samples the actuator back EMF.
During this time, the driver is not applying voltage to the actuator. To achieve equivalent performance between
the open loop and closed loop modes, it is useful to relate the peak clamp voltage to the average voltage. This
relationship is given by Equation 6.
(5)
(6)
Default Values:
DriveTime = 4.8 ms
IDissTime = BlankingTime = 75 µs
V
AVG
= 0.91 V
PEAK
(with default values)
LRA Mode (Open Loop)
The ODClamp[7:0] value sets the peak value when open loop LRA mode is used. Please note that LRA Open
Loop Mode can only be used with PWM inputs.
(7)
The V
RMS
value can be calculated from the peak value using the following equation:
(8)
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