52150 Datasheet, PDF (3/4 Pages) Micropac Industries – POSITIVE ADJUSTABLE 5-AMP VOLTAGE REGULATOR

52150/52175
POSITIVE ADJUSTABLE 5-AMP VOLTAGE REGULATOR
DESIGN CONSIDERATIONS
This device has thermal overload protection from excessive power and internal short circuit protection which limits the
circuit’s maximum current. Thus, the device is protected from overload abnormalities. Although the internal power
dissipation is limited, the junction temperature must be kept below the maximum specified temperature (150ºC). It is
recommended by the manufacturer that the maximum junction temperature be kept as low as possible for increased
reliability. To calculate the maximum junction temperature or heat sink required, the following thermal resistance
values should be used.
Package
TO-3
Where:
Type
Max
θ_JC
θ_JC
1.8
2.5
T_J = Junction Temperature
T_A = Ambient Temperature
P_D(MAX) =
T_J(max) – T_A
θ_JC + θ_CA
θ_CA = θ_CS + θ_SA
Solving for T_J = T_A + P_D (θ_JC+θ_CA)
θ_CA = Case-to-ambient thermal resistance
P_D = Power Dissipation θ_CS = Case-to-heat sink thermal resistance
θ_JC = Junction-to-case thermal resistance θ_SA = Heat sink-to-ambient thermal resistance
The device is designed to operate without external compensation components. However, the amount of external
filtering of these voltage regulators depends upon the circuit layout. If in a specific application the regulator is more
than four inches from the filter capacitor, a 2µF solid tantalum capacitor should be used at the input. A 1µF capacitor
should be used at the output to reduce transients created by fast switching loads, as seen in the basic test circuit.
These filter capacitors must be located as close to the regulator as possible.
Caution: Permanent damage can result from forcing the output voltage higher than the input voltage. A protection
diode from output to input should be used if this condition exists.
VOLTAGE OUTPUT
The device has an adjustable output voltage from 5.0V to 24V which can be programmed by the external resistor
network (potentiometer or two fixed resistors) using the relationship:
Example: If R1 = 0Ω and R2 = 5kΩ, Then
V_OUT = V_CONTROL x R1 + R2
V_OUT = 5V nominal.
R2
Or, if R1 = 10 kΩ and R2 = 5 kΩ then
V_OUT = 15V
Micropac Industries cannot assume any responsibility for any circuits shown or represent that they are free from patent infringement.
Micropac reserves the right to make changes at any time in order to improve design and to supply the best product possible.
MICROPAC INDUSTRIES, INC. HYBRID MICROELECTRONICS PRODUCTS DIVISION • 905 E. Walnut St., Garland, TX 75040 • [phone] • Fax [phone]
www.micropac.com E-MAIL: [e-mail] 12/13/01
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