LMT87

VOUT

VDD

SHUTDOWN

Any logic

device output

14

LMT87

SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017

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Typical Applications (continued)

9.2.2 Conserving Power Dissipation With Shutdown

Figure 15. Simple Shutdown Connection of the LMT87

9.2.2.1 Design Requirements

Because the power consumption of the LMT87 is less than 9 µA, it can simply be powered directly from any logic

gate output and therefore not require a specific shutdown pin. The device can even be powered directly from a

microcontroller GPIO. In this way, it can easily be turned off for cases such as battery-powered systems where

power savings are critical.

9.2.2.2 Detailed Design Procedure

Simply connect the VDD pin of the LMT87 directly to the logic shutdown signal from a microcontroller.

9.2.2.3 Application Curves

Time: 500 μs/div; Top trace: VDD 1 V/div;

Bottom trace: OUT 1 V/div

Figure 16. Output Turnon Response Time Without a

Capacitive Load and VDD = 3.3 V

Time: 500 μs/div; Top trace: VDD 1 V/div;

Bottom trace: OUT 1 V/div

Figure 17. Output Turnon Response Time With a 1.1-nF

Capacitive Load and VDD = 3.3 V

Time: 500 μs/div; Top trace: VDD 2 V/div;

Bottom trace: OUT 1 V/div

Figure 18. Output Turnon Response Time Without a

Capacitive Load and VDD = 5 V

Time: 500 μs/div; Top trace: VDD 2 V/div;

Bottom trace: OUT 1 V/div

Figure 19. Output Turnon Response Time With a 1.1-nF

Capacitive Load and VDD = 5 V

10 Power Supply Recommendations

The low supply current and supply range (2.7 V to 5.5 V) of the LMT87 allow the device to easily be powered

from many sources. Power supply bypassing is optional and is mainly dependent on the noise on the power

supply used. In noisy systems it may be necessary to add bypass capacitors to lower the noise that is coupled to

the output of the LMT87.