INA330

10

SBOS260

www.ti.com

FIGURE 9. Required 1.6kHz (or lower) Filtering.

FILTERING

Subsequent stages will frequently provide adequate filtering

for the INA330. However, filtering can be adjusted through

selection of RGCFILTER, and by adding a filter at VO for the

desired trade-off of noise and bandwidth. Adjustment of

these components will result in more or less ripple due to

auto-correction circuitry noise and will also affect broadband

noise.

It is generally desirable to keep any resistor added at VO (see

RO in Figure 9) relatively low to avoid DC gain error created

by the subsequent stage loading. This may result in relatively

high values for the filter capacitor at VO to produce the

desired filter response. The impedance of this filter can be

scaled higher to produce smaller capacitor values if the load

impedance is very high. Electrolytic capacitors are not rec-

ommended for the filters due to dielectric absorption effects.

FIGURE 8. Simple PI Temperature Control Amplifier.

R

G

200k

Ω

C

FILTER

500pF

INA330

REF3012

V

ADJ

R

SET

10k

Ω

R

THERM

10k

Ω

4

0.1

µF

V

EXCITE

1.25V

2

µF(1)

10M

Ω(1)

100pF(1)

2

3

10

1

+5V

95

6

8

7

OPA340

V

REF

2.5V

V

O

Output

to Power Amp

+5V

10M

Ω(1)

NOTE: (1) Time constants

were selected for THORLABS

model TCLM9 Laser Diode

Mount.

Proportional-Integrator

compensation is simpler to

adjust and often provides

adequate thermal transient

response.

8

7

2

3

10

1

R

G

200k

Ω

C

FILTER

500pF

C

O

1

µF

R

O

100

Ω

V

ADJ