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3 AMP POSITIVE STEP-DOWN
INTEGRATED SWITCHING REGULATOR
78ST300
Series
Standard Application
C1 = Optional 1F ceramic
C2 = Required 100F electrolytic
Pin-Out Information
Pin No. Function
1Vin
2
GND
3Vout
Ordering Information
78ST3
C
Output Voltage
XX
Y
05
= 5.0 Volts
Package Suffix
V
= Vertical Mount
H
= Horizontal
Mount
High Efficiency > 80%
Wide Input Range
Self-Contained Inductor
Short-Circuit Protection
Over-Temperature Protection
Fast Transient Response
The 78ST300 is a series of wide
input voltage, 3 terminal Integrated
Switching Regulators (ISRs). Employ-
ing a ceramic substrate, these ISRs
have a maximum output current of 3A.
The output voltage is laser trimmed
for high accuracy.
The 78ST300 series regulators
have internal short-circuit and over-
temperature protection and may be
used in a wide variety of applications.
Specifications
Characteristics
78ST300 SERIES
(T
a = 25°C unless noted)
Symbols
Conditions
Min
Typ
Max
Units
Output Current
Io
Over Vin range
0.1*
—
3.0
A
Input Voltage Range
Vin
Io = 0.1 to 3.0A
8
—
20
V
Output Voltage Tolerance
Vo
Over Vin range
—
±1.0
±2.0
%Vo
Ta = 0°C to +60°C
Line Regulation
Regline
Over Vin range
—
±0.4
±0.8
%Vo
Load Regulation
Regload
0.1
≤ Io ≤ 3.0A
—
±0.2
±0.4
%Vo
Ripple/Noise
Vn
Vin = Vin min, Io = 3.0A
—
1
—
%Vo
Transient Response
ttr
50% load change
—
100
—
Sec
(with 100F output cap)
Vo over/undershoot
5.0
%Vo
Efficiency
η
Vin = 9V, Io = 3.0A
—
80
—
%
Switching Frequency
o
Over Vin and Io ranges
0.95
1.0
1.05
MHz
Absolute Maximum
Ta
—
-40
—
+70
°C
Operating Temperature Range
Recommended Operating
Ta
Free Air Convection, (40-60LFM)
-40
—
+70**
°C
Temperature Range
Over Vin and Io ranges
Thermal Resistance
θ
ja
Free Air Convection, (40-60LFM)
—
35
—
°C/W
Storage Temperature
Ts
—
-40
—
+125
°C
Mechanical Shock
—
Per Mil-STD-883D, Method 2002.3
—
500
—
G’s
Mechanical Vibration
—
Per Mil-STD-883D, Method 2007.2,
—10
—
G’s
20-2000 Hz, soldered in a PC board
Weight
—
11
—
Grams
* ISR will operate down to no load with reduced specifications.
** See Thermal Derating chart.
Note: The 78ST300 Series requires a 100F electrolytic or tantalum output capacitor for proper operation in all applications.
78ST300
C2
+
Vout
GND
Vin
C1
1
2
3
(For dimensions and PC board
layout see Package Style 600.)
Revised 6/30/98