MC7912CT ON Semiconductor, MC7912CT Datasheet - Page 10

• Manufacturer Part Number: MC7912CT
• Description: IC REG VOLT NEG 1A 12V TO220AB
• Manufacturer: ON Semiconductor

Specifications of MC7912CT

• Regulator Topology: Negative Fixed
• Voltage - Output: -12V
• Voltage - Input: Down to -35V
• Voltage - Dropout (typical): 1.3V @ 1A
• Number Of Regulators: 1
• Current - Output: 1A
• Operating Temperature: 0°C ~ 125°C
• Mounting Type: Through Hole
• Package / Case: TO-220-3 (Straight Leads)
• Polarity: Negative
• Number Of Outputs: 1
• Output Type: Fixed
• Output Voltage: - 12 V
• Output Current: 1 A
• Line Regulation: 240 mV
• Load Regulation: 240 mV
• Input Voltage Max: - 35 V
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: 0 C
• Mounting Style: Through Hole
• Voltage Regulation Accuracy: 4 %
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Limit (min): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: MC7912CTOS

Protection Diodes
regulator it is sometimes necessary to add protection diodes
to prevent the capacitors from discharging through low
current points into the regulator or from output polarity
reversals. Generally, no protection diode is required for
values of output capacitance less then 10mF. Figure 11 shows
the MC7915 with the recommended protection diodes.
•
reversals during startup, power off and short-circuit
operation.
•
change in the input voltage. The measurement is made under
conditions of low dissipation or by using pulse techniques
such that the average chip temperature is not significantly
affected.
change in load current at constant chip temperature.
device dissipation for which the regulator will operate
within specifications.
When external capacitors are used with MC7900 series
Diode D
Line Regulation − The change in output voltage for a
Load Regulation − The change in output voltage for a
Maximum Power Dissipation − The maximum total
Opposite Polarity Protection
Reverse-bias Protection
1
protects the regulator from output polarity
80
70
60
50
40
30
Figure 12. D
0
Power Dissipation versus P.C.B. Copper Length
Vertically
Mounted
Free Air
5.0
2
PAK Thermal Resistance and Maximum
L, LENGTH OF COPPER (mm)
10
http://onsemi.com
DEFINITIONS
Minimum
Size Pad
P
R
D(max)
15
qJA
10
the MC7915 during an input short circuit or fast switch off
of power supply.
is not delivered to the load.
output, with constant load and no input ripple, measured
over a specified frequency range.
accelerated life test conditions with the maximum rated
voltage listed in the devices’ electrical characteristics and
maximum power dissipation.
for T
Diode D
Input Bias Current − That part of the input current that
Output Noise Voltage − The rms AC voltage at the
Long Term Stability − Output voltage stability under
A
20
Gnd
= +50°C
- 20 V
Input
L
2.0 oz. Copper
Î Î Î
Î Î Î
Î Î Î
Î Î Î
2
prevents output capacitor from discharging thru
25
L
Figure 11. Protection Diodes
+
1.0 mF
30
3.5
3.0
2.5
2.0
1.5
1.0
MC7915
D2
1N4001G
or Equiv
1.0 mF
+
D1
Output
-15 V
1N4001G
or Equiv
Gnd