Texas Instruments DRV8662EVM - DRV8662 Evaluation Module DRV8662EVM DRV8662EVM Datenbogen
Produktcode
DRV8662EVM
R13
4.99 kW
R18
7.5 kW
C13
0.1
F
m
C4
0.1
F
m
PWM-
IN-
R14
4.99 kW
R17
7.5 kW
C14
0.1
F
m
C5
0.1
F
m
PWM+
IN+
General Operation
3.5.1.1
Filter Selection Criteria
Apply these criteria to select an input filter.
1. First-order RC filters, both single-ended and differential, are recommended for 20 kHz and higher data
sample rates. The first-order filters have adequate settling time and the fewest components.
2. Second-order filters are recommended for noiseless operation when using a lower data sample rate
where a sharper cutoff is necessary.
3. The attenuation at the PWM carrier frequency should be at least –40 dB for haptic applications.
3.5.1.2
First-Order Filter
For sample rates 20 kHz and greater, a first-order filter is recommended. The first-order filter is used in
both single-ended or differential configurations.
both single-ended or differential configurations.
shows a differential, first-order filter. The PWM
input filter is optimized for a 3.3-V differential PWM input signal (–11-dB attenuation); remove R17 and
R18 when applying a 1.8-V input signal.
R18 when applying a 1.8-V input signal.
Figure 8. First-Order Input Filter
The first-order filter in
contains one pole with a slope of –20 dB.
shows the frequency
response of the first-order filter.
Figure 9. First-Order Frequency Response
11
SLOU319A – August 2011 – Revised December 2012
DRV8662 Piezo Haptics Driver Evaluation Module
Copyright © 2011–2012, Texas Instruments Incorporated