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7 8 S T 1 0 0 S e r i e s
1.5 AMP POSITIVE STEP-DOWN
INTEGRATED SWITCHING REGULATOR
Revised 6/30/98
• Very Small Footprint
The 78ST100 is a series of wide input
• High Efficiency > 85%
• Self-Contained Inductor
• Internal Short-Circuit Protection
• Over-Temperature Protection
• Fast Transient Response
• Wide Input Range
voltage, 3-terminal Integrated Switching
Regulators (ISRs). These ISRs have a maxi-
mum output current of 1.5A and an output
voltage that is laser trimmed to a variety of
industry standard voltages.
These 78 series regulators have excellent
line and load regulation with internal short-
circuit and over-temperature protection, are
very flexible, and may be used in a wide
variety of applications.
Pin-Out Information
Ordering Information
78ST1
C
XX Y
Pin Function
1
2
3
Vin
Output Voltage
Package Suffix
GND
Vout
Standard Application
33 = 3.3 Volts
36 = 3.6 Volts
05 = 5.0 Volts
51 = 5.1 Volts
65 = 6.5 Volts
07 = 7.0 Volts
08 = 8.0 Volts
09 = 9.0 Volts
12 = 12.0 Volts
V = Vertical Mount
S = Surface Mount
H = Horizontal
Mount
Vin
Vout
GND
1
3
78ST100
2
+
C1
GND
C2
C1 = Optional 1µF ceramic
C2 = Required 100µF electrolytic
Pkg Style 500
Specifications
78ST100 SERIES
Characteristics
(Ta = 25°C unless noted)
Symbols
Io
Conditions
Min
0.1*
—
Typ
—
Max
Units
A
Output Current
Over Vin range
Vin = Vin min
0.1 ≤ Io ≤ 1.5A
1.5
—
Short Circuit Current
Input Voltage Range
Isc
3.5
Apk
Vin
Vo= 3.3V
Vo= 5V
Vo= 12V
7
—
—
—
26
30
30
V
V
V
7
14.5
Output Voltage Tolerance
∆Vo
Over Vin range, Io=1.5A
Ta = 0°C to +60°C
—
±1.0
±2.0
%V
o
Line Regulation
Load Regulation
Vo Ripple/Noise
Regline
Regload
Vn
Over Vin range
—
—
—
±0.2
±0.1
±0.4
±0.2
—
%V
%V
o
0.1 ≤ Io ≤ 1.5A
o
Vin= 9V, Io= 1.5A
Vin= 16V, Io= 1.5A
Vo= 5V
Vo= 12V
65
90
mVpp
mVpp
Transient Response
ttr
50% load change
—
—
100
5
—
—
µSec
(with 100µF output cap)
Vo over/undershoot
%V
o
Efficiency
η
Vin= 10V, Io= 1A
Vin= 10V, Io= 1A
Vin= 17V, Io= 1A
Vo= 3.3V
Vo= 5V
—
—
—
80
85
90
—
—
—
%
%
%
Vo= 12V
Switching Frequency
ƒo
Over Vin range, Io=1.5A
—
600
650
700
kHz
Absolute Maximum
Operating Temperature Range
Ta
-40
—
+85
°C
Recommended Operating
Temperature Range
Ta
Free Air Convection, (40-60LFM)
At Vin= 24V, Io=1.0A
-40
—
+80**
°C
Thermal Resistance
Storage Temperature
Mechanical Shock
θja
Ts
—
—
Free Air Convection, (40-60LFM)
—
—
45
—
°C/W
°C
-40
—
—
+125
—
Per Mil-STD-883D, Method 2002.3
500
G’s
Mechanical Vibration
Per Mil-STD-883D, Method 2007.2,
20-2000 Hz, soldered in a PC board
—
—
—
5
G’s
Weight
—
—
6.5
—
grams
*ISR will operate down to no load with reduced specifications.
**See Thermal Derating chart.
Note: The 78ST100 Series requires a 100µF electrolytic or tantalum output capacitor for proper operation in all applications.
2
Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com