Texas Instruments DRV8662EVM - DRV8662 Evaluation Module DRV8662EVM DRV8662EVM Datenbogen
Produktcode
DRV8662EVM
General Operation
2.2
Connecting a Load
1. With the power supply off, connect the negative terminal of the load to OUT– and connect the positive
terminal of the load to OUT+.
2. Ensure the terminals are connected correctly, then enable the supply.
WARNING
Before connecting the load, ensure that the piezo actuator (or other
load) is rated for 200 V
load) is rated for 200 V
peak-to-peak
. If not, see the section
to adjust the DRV8662 maximum output voltage.
2.3
Output Waveforms
The MSP430 has eight different output modes that can be accessed using the pushbutton (TRIG). The
pushbutton will advance to the next mode and continue to cycle through each mode in a loop. Powering
off the EVM resets the board to Mode 1. A description of each mode is shown in
pushbutton will advance to the next mode and continue to cycle through each mode in a loop. Powering
off the EVM resets the board to Mode 1. A description of each mode is shown in
. Use the three
onboard LEDs [GAIN1, GAIN0, and ACTIVE (EN)] to determine the current output mode.
Table 2. Default EVM Modes
Mode
Description
Gain (dB)
V
OUT
GAIN1
GAIN0
EN
1
Sample Waveforms
0 / 1
(1)
28
50
0
0
2
External Analog/PWM Input
1
3
Sample Waveforms
0 / 1
(1)
34
100
0
1
4
External Analog/PWM Input
1
5
Sample Waveforms
0 / 1
(1)
38
150
1
0
6
External Analog/PWM Input
1
7
Sample Waveforms
0 / 1
(1)
40
200
1
1
8
External Analog/PWM Input
1
(1)
Enable is high only during waveform output.
NOTE:
To optimize the DRV8662 and reduce power losses, use the mode with an output voltage
(V
OUT
) closest to the actuator voltage requirements. For best performance, adjust the
feedback resistors so that the boost voltage is 5 V greater than the peak voltage requirement
of the actuator. See
of the actuator. See
for examples.
3
General Operation
This section guides you though the advanced configurations options of the DRV8662EVM including the
input, output, power supply, internal boost converter, and MSP430 firmware. Use the following sections to
configure the board for your specific application.
input, output, power supply, internal boost converter, and MSP430 firmware. Use the following sections to
configure the board for your specific application.
3.1
Power
The VBAT rail powers the DRV8662 directly and should be set between 3 V and 5.5 V. The MSP430 (U2)
and level-shifter (U4) are powered by an onboard LDO (U3) with an output voltage of 3.3 V.
and level-shifter (U4) are powered by an onboard LDO (U3) with an output voltage of 3.3 V.
To power the board:
1. Set an external power supply between 3.5 V and 5.5 V.
2. Connect the negative terminal of the power supply to VBAT– and the positive terminal of the power
supply to VBAT+.
4
DRV8662 Piezo Haptics Driver Evaluation Module
SLOU319A – August 2011 – Revised December 2012
Copyright © 2011–2012, Texas Instruments Incorporated