Datasheet

TINA-TI
VCC
VCC
Vref+ Vref+
Vref+
Rset 2.5M
VoA2
VoA1
-
+
+
3
1
5
4
2
U5 OPA369
-
+
+
3
1
5
4
2
U6 OPA369
1/2ofmatched
monolithicdual
NPNtransistors
(example:MMDT3904)
Input I 10n
uC Vref/2 2.5
V
+
VM1
VCC
VCC
Vref+
Vref+
V1 5
uC Vref/2 2.5
Vdiff
Vout
+
-
+
U1 OPA335
R3 14k
R8 10k
C1 1n
+
RG
RG
V+
V-
Ref
_
Out
2
1
8
3
6
7
5
4 U1 INA333
VCC
1/2ofmatched
monolithicdual
NPNtransistors
(example:MMDT3904)
NOTE: Temperaturecompensation
ofloggingtransistorsisnotshown.
Optionalbufferfordriving
SARconverterswith
samplingsystemsof 33kHz.³
RELATEDPRODUCTS
Formonolithiclogarithmicamplifiers(suchasLOG112orLOG114)seethelinkinfootnote1.
INA333
SBOS445B – JULY 2008 – REVISED OCTOBER 2008 ..................................................................................................................................................... www.ti.com
Virtual instruments offer users the ability to select
(FREE DOWNLOAD SOFTWARE)
input waveforms and probe circuit nodes, voltages,
and waveforms, creating a dynamic quick-start tool.
Using TINA-TI SPICE-Based Analog Simulation
Program with the INA333
Figure 38 and Figure 39 show example TINA-TI
circuits for the INA333 that can be used to develop,
TINA is a simple, powerful, and easy-to-use circuit
modify, and assess the circuit design for specific
simulation program based on a SPICE engine.
applications. Links to download these simulation files
TINA-TI is a free, fully functional version of the TINA
are given below.
software, preloaded with a library of macromodels in
addition to a range of both passive and active
NOTE: these files require that either the TINA
models. It provides all the conventional dc, transient,
software (from DesignSoft) or TINA-TI software be
and frequency domain analysis of SPICE as well as
installed. Download the free TINA-TI software from
additional design capabilities.
the TINA-TI folder .
Available as a free download from the Analog eLab
Design Center , TINA-TI offers extensive
post-processing capability that allows users to format
results in a variety of ways.
(1) The following link launches the TI logarithmic amplifiers web page: Logarithmic Amplifier Products Home Page
Figure 38. Low-Power Log Function Circuit for Portable Battery-Powered Systems
(Example Glucose Meter)
To download a compressed file that contains the TINA-TI simulation file for this circuit, click the following link:
Log Circuit .
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Product Folder Link(s): INA333