Datasheet

Capacitive load STLM20

10/19 Doc ID 12495 Rev 13

5 Capacitive load

The STLM20 will handle capacitive loads of up to 300 pF. Over the specified temperature

range, the STLM20 has a maximum output impedance of 160 Ω.

In a noisy environment, it may be advisable to add some filtering to minimize noise in the

output voltage. A 0.1 µF capacitor added between the supply voltage and ground is

recommended.

In an extremely noisy environment, it may be necessary to add a low-pass filter network to

the output of the device. A 1 µF capacitor, in addition to the output impedance of the device,

and a 200 Ω series resistor, will provide a low-pass filter that will pass the slow thermal time

constant of the STLM20, while filtering the higher frequency noise.

Figure 3. Filter network for noisy environments or capacitive loads > 300 pF

Table 7. Resistor/capacitor combinations for the filter network

FILTER

200 Ω 1 µF

470 Ω 0.1 µF

680 Ω 0.01 µF

1000 Ω 1000 pF

10 kΩ 100 pF

100 kΩ 10 pF

FILTER

GND

0.1µF

Bypass Capacitor

OUT

AI12259

FILTER

GND

0.1µF

Bypass Capacitor

OUT

AI12260