STLC60133
The bias level is programmed by the TTL logic level applied to the PWDN pins. The DGND pin is the logic
ground reference for the PWDN pins. For normal operation the BIAS pin shall be left open.
The BIAS control pin can be used to adjust the internal biasing and thus the quiescent current. By pulling out a
current of 0µA to 200µA, the quiescent current can be adjusted from 100% (full ON) to a full OFF condition.
However, considering the internal parameter spread to full shutdown the STLC60133 is recommended to pull
down a 250µA current from the BIAS pin. In the following figure is shown an implementation of a complete am-
plifier shutdown. To partially reduce the internal biasing also the PWDN pins can be used.
Figure 2. Logic drive of bias pin for complete Amplifier Shutdown.
3.3V
R2
50KΩ
R1
BIAS
R1 = 47KΩ for ± 12V
R1 = 22KΩ for ± 6V
D01TL492
STLC60133
THERMAL SHUTDOWN
A thermal protection is embedded in the STLC60133. In case of thermal overload the device is shut down at
160°C and returns to normal operation when the temperature becomes lower than 145°C.
During the thermal shutdown the voltage at the BIAS pin goes to the DGND rail; when the device returns to the
normal operation the voltage at the BIAS pin goes to the positive rail. In this condition the BIAS pin can be used
as thermal overload indicator.
MAXIMUM POWER DISSIPATION
Maximum Junction Temperature allowed for proper device operation is Tj = 140°C. A Typical Thermal Resis-
tance Junction to ambient of 29°C/W can be obtained mounting the device on a 4 layer board whithin 10 square
inches of copper and having the exposed pad contacting a proper copper area . It shall be noted that the ex-
posed pad of the device is electrically connected to the VSS negative supply.
Figure 3. Shutdown and alarm circuit
BIAS
VCC
200µA
STLC60133
10KΩ
PWDN0
SHUT
DOWN
PWDN1
BIAS
VEE
VBIAS=VCC -1.5V
BIAS
OR
0-200µA
+5V
10KΩ
VCC
+5V
OR
ALARM BIAS
1MΩ
100KΩ
1/4 HCF40109B
ST
D01TL491
10KΩ
ALARM
MIN β 350
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