THS6042_16 Datasheet, PDF (21/46 Pages) Texas Instruments – 350mA,12V ADSL CPE LINE DRIVERS

THS6042, THS6043
350 mA, ±12 V ADSL CPE LINE DRIVERS
SLOS264G − MARCH 2000 − REVISED DECEMBER 2001
APPLICATION INFORMATION
device protection features
The THS6042/3 have two built-in features that protect the devices against improper operation. The first
protection mechanism is output current limiting. Should the output become shorted to ground, the output current
is automatically limited to the value given in the data sheet. While this protects the output against excessive
current, the device internal power dissipation increases due to the high current and large voltage drop across
the output transistors. Continuous output shorts are not recommended and could damage the device.
The second built-in protection feature is thermal shutdown. Should the internal junction temperature rise above
approximately 180_C, the device automatically shuts down. Such a condition could exist with improper heat
sinking or if the output is shorted to ground. When the abnormal condition is fixed, the internal thermal shutdown
circuit automatically turns the device back on.
thermal information − PowerPAD
The THS6042/3 are available packaged in thermally-enhanced PowerPAD packages. These packages are
constructed using a downset leadframe upon which the die is mounted [see Figure 40(a) and Figure 40(b)]. This
arrangement results in the lead frame being exposed as a thermal pad on the underside of the package [see
Figure 40(c)]. Because this thermal pad has direct thermal contact with the die, excellent thermal performance
can be achieved by providing a good thermal path away from the thermal pad.
The PowerPAD package allows for both assembly and thermal management in one manufacturing operation.
During the surface-mount solder operation (when the leads are being soldered), the thermal pad can also be
soldered to a copper area underneath the package. Through the use of thermal paths within this copper area,
heat can be conducted away from the package into either a ground plane or other heat dissipating device. This
is discussed in more detail in the PCB design considerations section of this document.
The PowerPAD package represents a breakthrough in combining the small area and ease of assembly of
surface mount with the, heretofore, awkward mechanical methods of heatsinking.
DIE
Side View (a)
Thermal
Pad
DIE
End View (b)
Bottom View (c)
NOTE A: The thermal pad is electrically isolated from all terminals in the package.
Figure 40. Views of Thermally Enhanced PWP Package
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
21