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Filtering and Adapting PWM Waveforms

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SLOU403C – March 2015 – Revised June 2018

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DRV2700EVM High Voltage Piezo Driver Evaluation Kit

8.2.3

Remove Filter for Analog Input

If the input signal is an analog waveform, as opposed to a PWM, then an input filter may not be
necessary. Before removing the filter, ensure that a simple RC filter is not needed to remove any artifacts
from the digital-to-analog converter (DAC) output or other input source. Follow these instructions to
remove the input filter completely.

1. Replace resistors R6, R7, R13, and R14 with 0-

Ω

resistors

2. Remove resistors R17 and R18

3. Remove capacitors C8, C9, C13, and C14. Do not remove ac coupling capacitors C4 and C5.

See

Figure 13

for a diagram of the input configuration.

Summary of Contents for DRV2700EVM

Page 1: ...to isolate power consumption on DRV2700 8 convenient boost voltage settings and 4 different gain settings Small footprint 9 mm x 13 mm Breakout for usage as a boost converter The evaluation kit is de...

Page 2: ...WM Analog and Single Ended Inputs 15 5 1 PWM AC Coupled Input Using MSP430 15 5 2 PWM AC Coupled Input Using AIN 15 5 3 External Analog AC Coupled Input 16 5 4 Single Ended DC Coupled Input 16 6 Outpu...

Page 3: ...by the U S EU and other Export Administration Regulations including software or any controlled product restricted by other applicable national regulations received from Disclosing party under this Agr...

Page 4: ...arning Do not leave EVM powered when unattended HOT SURFACE Warning Hot Surface Contact may cause burns Do not touch Please take the proper precautions when operating HIGH VOLTAGE Danger High Voltage...

Page 5: ...a where the TI HV EVM and its interface electronics are energized indicating operation of accessible high voltages may be present for the purpose of protecting inadvertent access 4 All interface circu...

Page 6: ...ini B USB cable The default board settings cause the microcontroller MSP430 to control the inputs of the DRV2700 at power up The MSP430 has each of these control settings low which disables the DRV270...

Page 7: ...er supply USB top 1 X MSP connected to USB power supply VIN bottom 1 MSP connected to VIN power supply JP11 DRV Open DRV2700 not connected to either power supply VIN top 1 DRV2700 connected to VIN pow...

Page 8: ...and VEXTERNAL Ext VIN on the EVM Each of these inputs can be used to power the entire board or parts of the board 2 3 1 USB Power Input The USB power input can be supplied from a standard USB port on...

Page 9: ...logic level low through internal pulldown resistor This is done by removing the configuration jumper Driven externally This is done by connecting the external control signal to the center 100 mil head...

Page 10: ...block to mitigate touching between two high voltage lines See the Output section for additional information 2 7 BST PVDD Disconnect The BST jumper JP12 is provided to allow disconnecting between PVDD...

Page 11: ...018 Submit Documentation Feedback Copyright 2015 2018 Texas Instruments Incorporated DRV2700EVM High Voltage Piezo Driver Evaluation Kit 3 EVM Control Software GUI By default the DRV2700EVM can be con...

Page 12: ...e used in the format of Note TimeOn TimeOff as shown in Figure 7 The note format is A G including sharps but not flats b followed by the octave and the frequency is in Hz rounded to the nearest intege...

Page 13: ...here VFB 1 32 V and REQ is the equivalent resistor between all the connected resistors in parallel Refer to Table 4 for BST setting based on the jumper configuration WARNING Be sure not to hot switch...

Page 14: ...lection Inductor selection plays a critical role in the performance of the DRV2700 The range of recommended inductor values is 3 3 H to 22 H When a larger inductance is chosen the DRV2700 boost conver...

Page 15: ...00EVM in MSP430 PWM input mode the onboard MSP430 generates a differential PWM signal that is sent through a low pass filter to the DRV2700 The DRV2700EVM is setup to use this mode by default Set to d...

Page 16: ...plications it is critical that the output does not go above or below a certain threshold To help mitigate this landing pads for a zener diode on the DC input have been provided Installing a properly s...

Page 17: ...to be operated in the linear region the set reference configuration should be used Use the DC input with a floating reference to drive the DRV2700 with the following instructions 1 Disconnect the MSP4...

Page 18: ...ig PWM Analog and Single Ended Inputs www ti com 18 SLOU403C March 2015 Revised June 2018 Submit Documentation Feedback Copyright 2015 2018 Texas Instruments Incorporated DRV2700EVM High Voltage Piezo...

Page 19: ...output of the amplifier VOUT These outputs can be configured in a variety of ways and are described in more detail in this section 6 1 Two Terminal Differential Output Configuration OUT OUT The typic...

Page 20: ...capacitive loads however an improper load driven at certain levels can cause the device to heat up and hit thermal shutdown Therefore there are several key specifications to consider when choosing a P...

Page 21: ...a low pass filter is required The primary parameters for determining the input filter are the PWM input frequency and sample rate Because of the power ratings of the DRV2700 the input filter has been...

Page 22: ...s 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 8 2 1 First Or...

Page 23: ...er is recommended A differential input signal is recommended for use with a second order filter because of the longer settling time Figure 20 shows the differential second order filter that is the def...

Page 24: ...ed to a PWM then an input filter may not be necessary Before removing the filter ensure that a simple RC filter is not needed to remove any artifacts from the digital to analog converter DAC output or...

Page 25: ...22 3 3k R23 Green 1 2 D4 511 R25 Green 1 2 D5 511 R26 Green 1 2 D6 511 R27 EN GAIN1 GAIN0 3 3k R24 GND GND GND 1 2 J5 1 2 3 JP9 1 2 3 JP8 1 2 3 JP7 1 2 3 JP10 VIN 1 2 3 JP11 VIN VBUS 1 2 3 J3 GND TP6...

Page 26: ...e 2018 Submit Documentation Feedback Copyright 2015 2018 Texas Instruments Incorporated DRV2700EVM High Voltage Piezo Driver Evaluation Kit 9 2 PCB Layout Figure 23 through Figure 27 show the DRV2700E...

Page 27: ...e 27 SLOU403C March 2015 Revised June 2018 Submit Documentation Feedback Copyright 2015 2018 Texas Instruments Incorporated DRV2700EVM High Voltage Piezo Driver Evaluation Kit Figure 25 Mid Layer 1 Fi...

Page 28: ...155C80J224KE01D Murata C9 1 0 47 F CAP CERM 0 47uF 10V 10 X7R 0603 603 C0603C474K8RACTU Kemet C13 C16 C19 C20 4 0 1 F CAP CERM 0 1uF 16V 10 X7R 0402 402 GRM155R71C104KA88D Murata C14 C15 C17 C18 4 0 0...

Page 29: ...0 063W 0402 402 CRCW04022K70JNED Vishay Dale R20 R28 R29 3 10 k RES 10 k 5 0 063W 0402 402 CRCW040210K0JNED Vishay Dale R21 1 6 04 k RES 6 04 k 1 0 063W 0402 402 CRCW04026K04FKED Vishay Dale R25 R26...

Page 30: ...5 in BST Network JP2 JP3 and JP4 image 13 Revision History Changes from A Revision April 2015 to B Revision Page Changed content in JP11 row of the Default Jumper Settings table 7 Changed connector li...

Page 31: ...set forth above or credit User s account for such EVM TI s liability under this warranty shall be limited to EVMs that are returned during the warranty period to the address designated by TI and that...

Page 32: ...the antenna types listed in the user guide with the maximum permissible gain and required antenna impedance for each antenna type indicated Antenna types not included in this list having a gain great...

Page 33: ...t the EVM user guide prior to connecting any load to the EVM output If there is uncertainty as to the load specification please contact a TI field representative During normal operation even with the...

Page 34: ...OST OF REMOVAL OR REINSTALLATION ANCILLARY COSTS TO THE PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES RETESTING OUTSIDE COMPUTER TIME LABOR COSTS LOSS OF GOODWILL LOSS OF PROFITS LOSS OF SAVINGS LOSS OF...

Page 35: ...TI Resource NO OTHER LICENSE EXPRESS OR IMPLIED BY ESTOPPEL OR OTHERWISE TO ANY OTHER TI INTELLECTUAL PROPERTY RIGHT AND NO LICENSE TO ANY TECHNOLOGY OR INTELLECTUAL PROPERTY RIGHT OF TI OR ANY THIRD...

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