Capacitive load

STLM20

10/16

5

Capacitive load

The STLM20 will handle capacitive loads of up to 300pF. 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 0.1µF 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 1µF 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 > 300pF

Table 7.

Resistor/capacitor combinations for the filter network

200

Ω

1µF

470

Ω

0.1µF

680

Ω

0.01µF

1000

Ω

1000pF

10k

Ω

100pF

100k

Ω

10pF

VCC

RFILTER

CFILTER

GND

0.1µF

Bypass Capacitor

VOUT

CL

AI12259

VCC

RFILTER

CFILTER

GND

0.1µF

Bypass Capacitor

VOUT

CL

AI12260