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MC78TXX
3-Terminal 3A Positive Voltage Regulator
Features
• • • • • • • • Output Current in Excess of 3.0A Output Transistor Safe Operating Area Compensation Power Dissipation :25W Internal Short Circuit Current Limiting Internal Thermal Overload Protection Output Voltage Offered in 4% Tolerance No External Components Required Output Voltage of 5,12 and 15V
Description
This family of fixed voltage regulators are monolithic integrated circuit capable of driving loads in excess of 3.0 A.
TO-220
GND
1
1.Input 2. GND 3. Output
Internal Block Diagram
INPUT 1 CURRENT GENERATOR
SERIES PASS ELEMENT
OUTPUT 3
SOA PROTECTION
STARTING CIRCUIT
REFERENCE VOLTAGE
ERROR AMPLIFIER
THERMAL PROTECTION
GND 2
Rev. 1.0.1
©2002 Fairchild Semiconductor Corporation
MC78TXX
Absolute Maximum Ratings
Parameter Input Voltage (for VO = 5V to 12V) (for VO = 15V) Power Dissipation Thermal Resistance, Junction to Air (Note1, 2) Ta = +25°C Thermal Resistance, Junction to Case (Note1) Tc = +25°C Operating Junction Temperature Range Storage Temperature Range
Note: 1. Thermal resistance test board Size: 76.2mm * 114.3mm * 1.6mm(1S0P) JEDEC standard: JESD51-3, JESD51-7 2. Assume no ambient airflow.
Symbol VI PD RθJA RθJC TJ TSTG
Value 35 40 Internally limited 65 2.5 0 ~ +125 -65 ~ +150
Unit V V
°C/W °C/W °C °C
Electrical Characteristics(MC78T05)
(VI = 10V, IO = 3.0 A, 0°C ≤ TJ ≤ +125°C, Po ≤ PMAX (Note3), unless otherwise specified. ) Parameter Output Voltage Symbol Vo Conditions 5mA ≤ Io ≤ 3.0A , TJ = +25°C 7.3V ≤ VI ≤ 20V, 5mA ≤ Io ≤ 2.0A 7.2V ≤ VI ≤ 35V , Io=5mA, TJ =+25°C 7.2V ≤ VI ≤ 35V , Io=1.0A, TJ = +25°C 7.5V ≤ VI ≤ 20V, Io =2.0A, TJ = +25°C 8.0V ≤ VI ≤ 12V, Io =3.0A, TJ = +25°C 5mA ≤ Io ≤ 3.0A , TJ = +25°C 5mA ≤ Io ≤ 3.0A Pulse =10ms, P = 20W TA = +25°C 5mA ≤ Io ≤ 3.0A , TJ = +25°C 5mA ≤ Io ≤ 3.0A 7.2V ≤ VI ≤ 35V, Io = 5mA TJ = +25°C ; 7.5V ≤ VI ≤ 20V, Io =2.0A ; 5mA ≤ Io ≤ 3.0A, TJ = +25°C f = 120Hz, 8V ≤ VI ≤ 18V, Io = 2.0A TJ = +25°C Io = 3A ,TJ = +25°C TA = +25°C, 10Hz ≤ f ≤ 100kHz TA = +25°C f = 1.0kHz VI = 35V, TJ =+25°C Io = 5.0mA Min. 4.8 4.75 Typ. 5.0 5.0 3.0 10 15 0.002 3.5 4.0 0.1 Max. 5.2 5.25 25 30 80 0.03 5.0 6.0 0.8 Unit V
Line Regulation (Note4)
∆VO
mV mV mV %Vo/W mA mA mA
Load Regulation (Note4) Thermal Regulation Quiescent Current
∆VO REGT IQ
-
Quiescent Current Change
∆ IQ
-
Ripple Rejection Dropout Voltage Output Noise Voltage Peak Output Current Output Resistance Short Circuit Current Limit
RR VD VN IPK Ro Isc
-
75 2.2 10 5.0 2.0 1.5 0.2
2.5 2.5 -
dB V µV/Vo A mΩ A mV/°C
Average Temperature ∆VO/∆T Coefficient of Output Voltage
Note:
3. Although power dissipation is internally limited, specifications apply only for PO ≤ Pmax, Pmax = 25W 4. Load and line regulation are specified at constant junction temperature. Change in Vo due heating effects must be taken into account separately. Pulse testing with low duty is used.
2
MC78TXX
Electrical Characteristics(MC78T12) (Continued)
(VI = 19V, IO =.