3.6 Basic Operation Examples
CA5350
3-20
CURRENT INPUT
-
I/V GAIN
FILTER
10
INVERTING OUTPUT
×10 GAIN
×10
×1
Figure 3-13 CA5350 outline block diagram
When SNR is very important for you, setting
I/V GAIN
as large as possible, and
×10
GAIN
(output amplifier gain) to
×1
would help. When high speed response is needed, you
can set output amplifier gain to
×10
, and set
I/V GAIN
to a low value.
3.6.4.4 Filter Setting
The equipment is equipped with filters for rejection a noise from input signal and
improving the SNR. Filters characteristics have Bessel characteristics (2
nd
order) and it
is of low-pass type. Overshoot does not occur in the pulse response, because of Bessel
characteristics.
Filters are set in terms of rise time. Moreover, it is possible that filter is bypassed for
getting the maximum speed and there is also an auto filter function that automatically
sets the optimum filter with respect to
I/V GAIN
.
Using the filter
Select
ON
or
OFF
in the Menu
FILTER
.
F I L T E R
S
O N * O F F
In the above, the current setting is
OFF
, and cursor appears below ON. Pressing the
ENTER
key in this state will enable the filter.
Setting the filter to
OFF
(do not use) will disable the noise reject, but response
properties will become fastest. When the fastest response is required, use it with the
OFF
state.
Filter rise time can be set with two methods, namely, manual setting method (
MANUAL
)
and automatic setting method according to
I/V GAIN
(
AUTO
).
Manually setting the filter response (rise time)
Set from the Menu
FILTER
–ON–MANUAL–RISE TIME
. Setting range is 1µs ~ 300ms and
sequence is 1-3, and total 12 types of settings can be made.
F I L T E R
S
R I S E
*
T I M E
*
1 0 0 u s
Select the rise time with the
▴
,
▾
keys and knob, and press the
ENTER
key to
apply the settings.
The larger (longer) the filter rise time is set, the smaller the bandwidth. Therefore,
more noise components can be rejected, which will improve the SNR. However, response
of signal will become slow, and original waveform information may be lost.
