TSV7721 datasheet(23/40 Pages) STMICROELECTRONICS

23 / 40 page

5.9

Shutdown function (TSV7723)

The operational amplifier is enabled when the EN pin is pulled high. To disable the amplifier, the EN must be

pulled down to VCC-. When in shutdown mode, the amplifier output is in a high impedance state. The EN pin

must never be left floating, but must be tied to VCC+ or VCC-.

The turn-on time is calculated for an output variation of ± 200 mV (see Figure 47 & Figure 48. Figure 51 shows

the test configurations).

Figure 50. Test configuration

Vcc-0.5 V

+Vcc

DUT

GND

5.10

PCB layout recommendations

Particular attention must be paid to the layout of the PCB tracks connected to the amplifier, load, and power

supply. The power and ground traces are critical as they must provide adequate energy and grounding for

all circuits. The best practice is to use short and wide PCB traces to minimize voltage drops and parasitic

inductance. In addition, to minimizing parasitic impedance over the entire surface, a multi-via technique that

connects the bottom and top layer ground planes together in many locations is often used. The copper traces that

connect the output pins to the load and supply pins should be as wide as possible to minimize trace resistance.

5.11

Decoupling capacitor

In order to ensure op amp full functionality, it is mandatory to place a decoupling capacitor of at least 22 nF as

close as possible to the op amp supply pins. A good decoupling helps to reduce electromagnetic interference

impact.

5.12

Macro model

Accurate macro models of the TSV7722 device are available on the STMicroelectronics’ website at: www.st.com.

These models are a trade-off between accuracy and complexity (that is, time simulation) of the TSV7722

operational amplifier. They emulate the nominal performance of a typical device at 25°C within the specified

operating conditions mentioned in the datasheet. They also help to validate a design approach and to select the

right operational amplifier, but they do not replace on-board measurements.

TSV7721, TSV7722, TSV7723

Shutdown function (TSV7723)

DS13614 - Rev 3

page 23/40

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