Piezo
Element
DRV2700
Piezo
Element
BST
OUT
>
OUT+
GND
100 Vp
100 Vp
Output
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SLOU403C – March 2015 – Revised June 2018
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DRV2700EVM High Voltage Piezo Driver Evaluation Kit
6.3
Three Terminal Single Ended Output Configuration (BST to OUT± to GND)
The output configuration is very similar to the two terminal, however, only one output pin is used. This
ensures that the two voltage potentials (BST to OUTx and OUTx to GND) always add up to BST.
Figure 16. Three Terminal Single Ended Output
7
Load Selection
The DRV2700 is intended to drive Piezo (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 Piezo load; such as dimensions, blocking force, and
displacement. However, the key electrical specifications from the driver perspective are voltage rating and
capacitance. At the maximum frequency of 500 Hz, the DRV2700 is optimized to drive up to 50 nF at 200
VPP, which is the highest voltage swing capability. The DRV2700 will drive larger capacitances if the
programmed boost voltage is lowered or the user limits the input frequency range to lower frequencies (for
example, 300 Hz). For more information, see the
Piezo Load Selection
section of the DRV2700 data sheet
(
SLOS861
).
See
Figure 13
for a diagram of the input configuration.
