SNIS119F May 2004 – August 2017 LM60
Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.
The device has a low supply current and a wide supply range, therefore it can easily be driven by a battery.
The device handles capacitive loading well. Without any special precautions, the device can drive any capacitive load as shown in Figure 12. Over the specified temperature range the device has a maximum output impedance of 800 Ω. In an extremely noisy environment, adding some filtering to minimize noise pick-up may be required. TI recommends that 0.1 μF be added from +VS to GND to bypass the power supply voltage, as shown in Figure 13. In a noisy environment, adding a capacitor from the output to ground may be required. A 1-μF output capacitor with the 800-Ω output impedance forms a 199-Hz, low-pass filter. Because the thermal time constant of the device is much slower than the 6.3-ms time constant formed by the RC, the overall response time of the device is not be significantly affected. For much larger capacitors, this additional time lag increases the overall response time of the device.
Because the LM60 is a simple temperature sensor that provides an analog output, design requirements related to the layout are also important. Refer to Layout for details.
For this design example, use the design parameters listed in Table 1.
|TEMPERATURE (T)||TYPICAL VO|
Selection of the LM60 is based on the output voltage transfer function being able to meet the needs of the rest of the system.
A simple thermostat can be created by using a reference (LM4040) and a comparator (LM7211) as shown in Figure 16.
The LM60 draws very little power, therefore it can simply be shutdown by driving the LM60 supply pin with the output of a logic gate as shown in Figure 18.