7.2.3 Single-Supply Piezoelectric Driver

Some piezoelectric transducers can be referenced to ground as shown in Figure 7-4. The wide supply voltage

of the OPAx596 enables designers to drive a high voltage transducer up to 85V, without having to use the

more complicated bridge tied load configuration. The piezoelectric load presents a large capacitance at the

output of the amplifier and proper compensation is required to avoid instability. Also consider the output current

drive requirement. The current drive requirement is determined by the frequency of operation and the effective

capacitance of the load. High frequency and large capacitance reduce the effective impedance of the load and

thereby increase the current drive requirement. The OPAx596 are an excellent choice to drive piezoelectric loads

at dc and low frequency.

+

–

5k

75k

OPA596

DAC

5V

85V

80V

+

−

Figure 7-4. 80V Single-Supply Piezoelectric Driver

7.2.4 High-Side Current Sense

The OPAx596 enables high voltage current sense measurements. High-side voltage measurements of ±100V

or more can be easily implemented using the OPAx596. The voltage capability is proportional to the gain of the

sense circuit and the input common-mode range of the amplifier. Figure 7-5 shows the OPA596 configured for

a ±500V high side current measurement and a gain of 2. A high precision amplifier is used as a gain stage to

amplify the signal further.

Make the input resistors large enough to avoid any loading related errors. The low input bias current of the

OPAx596 allows for the use of larger resistors when compared to other power amplifiers and is not a major

contribution to the total error in this application. Special consideration of input bias current, thermal noise, and

input common-mode range is warranted when choosing resistors for this design.

1M

49.9k

OPA596

42.5V

42.5V

R

shunt = 100m

1M

1.3k

DUT

ADC

PA

DAC

+

–

RG

RF

99k

1k

OPA189

49.9k

51.1k

Figure 7-5. ±500V High-Side Current Sense

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OPA596

SBOSA42A – JUNE 2024 – REVISED FEBRUARY 2025

Copyright © 2025 Texas Instruments Incorporated

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Product Folder Links: OPA596