adl5304 Analog Devices, Inc., adl5304 Datasheet - Page 24

• Manufacturer Part Number: adl5304
• Description: High Speed, 200 Db Range, Logarithmic Converter
• Manufacturer: Analog Devices, Inc.

ADL5304
Log Ratio Operation
Because the
ratio operation is possible. The only difference between I
and I
allows adaptive photodiode bias at this input only. Assuming
that the ratio I
than unity, V
supply in some cases. The value of V
minimum ratio and the slope chosen for the application.
DEN
is that the I
ADL5304
LOG
NUM
can be of either polarity, requiring a negative
/I
DEN
MON
has two equal inputs, I
can, in general, be either greater or less
current derives from the I
LOG
depends on the
NUM
and I
NUM
signal and
DEN
NUM
, log
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For example, if the ratio can vary from 1:1000 to 1000:1 and a slope
of 20 mV/dB is required, the peak swing is ±1.2 V around V
Option 5 in Table 4 provides this with an intercept I
(V
results in 0.3 V ≤ V
OFS
= 1.5 V) with V
LOG
LOG
≤ 2.7 V.
= ±1.2 V around V
OFS
= 1.5 V, which
Data Sheet
Z
of 17.8 pA
OFS
.