L78M12ABDT STMicroelectronics, L78M12ABDT Datasheet - Page 17

• Manufacturer Part Number: L78M12ABDT
• Description: V REG 0.5A +12V, SMD, 78M12, DPAK-3
• Manufacturer: STMicroelectronics

Specifications of L78M12ABDT

• Primary Input Voltage: 19V
• Output Voltage: 12V
• Dropout Voltage Vdo: 2V
• No. Of Pins: 3
• Output Current: 500mA
• Voltage Regulator Case Style: TO-252
• Operating Temperature Range: -40°C To +125°C
• Polarity: Positive
• Number Of Outputs: 1
• Output Type: Fixed
• Line Regulation: 100 mV
• Load Regulation: 240 mV
• Dropout Voltage (max): 2 V
• Input Voltage Max: 35 V
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Package / Case: TO-252
• Mounting Style: SMD/SMT
• Voltage Regulation Accuracy: 2 %
• Output Voltage Fixed: 12V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7
7.1
Figure 17. Current regulator
Figure 18. Adjustable output regulator
V
V
O
I
- V
= 7.0 V to 20 V
O
I
O
≥ 2.0 V
= V
Applications information
Design considerations
The L78MxxA series of fixed voltage regulators are designed with thermal overload
protection that shuts down the circuit when subjected to an excessive power overload
condition, internal short-circuit protection that limits the maximum current the circuit will
pass, and output transistor safe-area compensation that reduces the output short-circuit as
the voltage across the pass transistor is increased. In many low current applications,
compensation capacitors are not required. However, it is recommended that the regulator
input be bypassed with a capacitor if the regulator is connected to the power supply filter
with long wire lengths, or if the output load capacitance is large. An input bypass capacitor
should be selected to provide good high-frequency characteristics to insure stable operation
under all load conditions. A 0.33 µF or larger tantalum, mylar, or other capacitor having low
internal impedance at high frequencies should be chosen. The bypass capacitor should be
mounted with the shortest possible leads directly across the regulators input terminals.
Normally good construction techniques should be used to minimize ground loops and lead
resistance drops since the regulator has no external sense lead.
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+I
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Doc ID 2147 Rev 9
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