For assistance or to order, call (800) 531-5782
Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com
2
Revised 6/30/98
Standard Application
C1 = Optional 1µF ceramic
C2
= Required 100µF electrolytic
Pin-Out Information
Pin Function
1V
in
2 GND
3V
out
Ordering Information
78ST1
C
XX Y
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
Package Suffix
V = Vertical Mount
S = Surface Mount
H = Horizontal
Mount
1.5 AMP POSITIVE STEP-DOWN
INTEGRATED SWITCHING REGULATOR
• Very Small Footprint
• High Efficiency > 85%
• Self-Contained Inductor
• Internal Short-Circuit Protection
• Over-Temperature Protection
• Fast Transient Response
• Wide Input Range
The 78ST100 is a series of wide input
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.
78ST100 Series
Output Voltage
Specifications
Characteristics
78ST100 SERIES
(T
a
= 25°C unless noted) Symbols Conditions Min Typ Max Units
Output Current I
o
Over V
in
range 0.1* — 1.5 A
Short Circuit Current I
sc
V
in
= V
in
min — 3.5 — Apk
Input Voltage Range V
in
0.1 ≤ I
o
≤ 1.5A V
o
= 3.3V 7 — 26 V
V
o
= 5V 7 — 30 V
V
o
= 12V 14.5 — 30 V
Output Voltage Tolerance ∆V
o
Over V
in
range, I
o
=1.5A
— ±1.0 ±2.0 %V
o
T
a
= 0°C to +60°C
Line Regulation Reg
line
Over V
in
range — ±0.2 ±0.4 %V
o
Load Regulation Reg
load
0.1 ≤ I
o
≤ 1.5A — ±0.1 ±0.2 %V
o
V
o
Ripple/Noise V
n
V
in
= 9V, I
o
= 1.5A V
o
= 5V — 65 — mV
pp
V
in
= 16V, I
o
= 1.5A V
o
= 12V 90 mV
pp
Transient Response t
tr
50% load change — 100 — µSec
(with 100µF output cap) V
o
over/undershoot — 5 — %V
o
Efficiency η V
in
= 10V, I
o
= 1A V
o
= 3.3V — 80 — %
V
in
= 10V, I
o
= 1A V
o
= 5V — 85 — %
V
in
= 17V, I
o
= 1A V
o
= 12V — 90 — %
Switching Frequency ƒ
o
Over V
in
range, I
o
=1.5A 600 650 700 kHz
Absolute Maximum T
a
—
-40 — +85 °C
Operating Temperature Range
Recommended Operating T
a
Free Air Convection, (40-60LFM)
Temperature Range At V
in
= 24V, I
o
=1.0A
-40 — +80** °C
Thermal Resistance θ
ja
Free Air Convection, (40-60LFM) — 45 — °C/W
Storage Temperature T
s
— -40 — +125 °C
Mechanical Shock — Per Mil-STD-883D, Method 2002.3 — 500 — G’s
Mechanical Vibration — Per Mil-STD-883D, Method 2007.2,
—5
—
G’s
20-2000 Hz, soldered in a PC board
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.
78ST100
C2
+
Vout
GNDGND
Vin
C1
1
2
3
Pkg Style 500
