Datasheet

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SBOS156B − MARCH 1987 − REVISED APRIL 2008
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13
9. With these preparatory steps in place, the PowerPAD
IC is simply placed in position and run through the
solder reflow operation as any standard surfacemount
component. This preparation results in a properly
installed part.
For detailed information on the PowerPAD package,
including thermal modeling considerations and repair
procedures, see technical brief SLMA002 PowerPAD
Thermally-Enhanced Package available for download at
www.ti.com.
OPTIONAL:
REQUIRED:
Thermal Land
(Copper)
Minimum Size
4.8mm x 3.8mm
(189 mils x 150 mils)
Additional four vias outside
of thermal pad area but
under the package.
Thermal pad area 2.286mm x 2.286mm
(90 mils x 90 mils) with five vias
(via diameter = 13 mils)
Figure 14. 8-Pin PowerPAD PCB Etch and Via
Pattern
TYPICAL APPLICATIONS
OPA445
R
1
Compliance Voltage Range =
±
35V
NOTE: R
1
=R
3
and R
2
=R
4
+R
5
+40V
100k
Ω
R
2
10k
Ω
R
3
100k
Ω
R
4
9.9k
Ω
−
40V
R
5
100
Ω
I
L
Load
I
L
=[(V
2
−
V
1
)/R
5
](R
2
/R
1
)
=(V
2
−
V
1
)/1k
Ω
V
2
V
1
Figure 15. Voltage-to-Current Converter
OPA445
0−2mA
+60V
25k
Ω
−
12V
V
O
= 0V to +50V
at 10mA
0.1
µ
F
0.1
µ
F
Protects DAC
During Slewing
DAC8811
or
DAC7811
Figure 16. Programmable Voltage Source
+45V
160V
Piezo
(1)
Crystal
−
45V
Master
R
2
9k
Ω
R
1
1k
Ω
V
IN
±
4V
OPA445
+45V
−
45V
Slave
R
4
10k
Ω
R
3
10k
Ω
OPA445
NOTE: (1) For transducers with large capacitance the stabilization
technique described in Figure 6 may be necessary. Be certain that the
Master amplifier is stable before stabilizing the Slave amplifier.
Figure 17. Bridge Circuit Doubles Voltage for Piezo Crystals