For assistance or to order, call (800) 531-5782
7 8 H T 3 0 0 S e r i e s
3 AMP POSITIVE STEP-DOWN
INTEGRATED SWITCHING REGULATOR
Revised 6/30/98
The 78HT300 is a series of wide
• High Efficiency > 80%
input voltage, 3 terminal Integrated
Switching Regulators (ISRs). Em-
ploying a ceramic substrate, these
ISRs have a maximum output current
of 3A. The output voltage is laser-
trimmed for high accuracy.
• Wide Input Range
• Self-Contained Inductor
• Short-Circuit Protection
• Over-Temperature Protection
• Fast Transient Response
The 78HT300 series regulators
have internal short-circuit and over-
temperature protection and may be
used in a wide variety of applications.
Ordering Information
Pin-Out Information
78HT3
C
Y
XX
Pin No. Function
Standard Application
1
2
3
V
in
GND
Vout
Output Voltage
Package Suffix
Vin
1
Vout
GND
3
V = Vertical Mount
H = Horizontal
Mount
05 = 5.0 Volts
53 = 5.25 Volts
78HT300
+
C1
GND
2
C2
(For dimensions and PC board
layout see Package Style 600.)
C1 = Optional 1µF ceramic
C2 = Required 100µF electrolytic
Specifications
78HT300 SERIES
Characteristics
(Ta = 25°C unless noted)
Symbols
Conditions
Min
Typ
—
Max
3.0
28
Units
A
Output Current
Io
Over Vin range
0.1*
Vo+3
Input Voltage Range
Output Voltage Tolerance
Vin
∆Vo
Io = 0.1 to 3.0A
Over Vin range
Ta = 0°C to +60°C
—
V
—
±1.0
±2.0
%Vo
Line Regulation
Load Regulation
Ripple/Noise
Regline
Regload
Vn
Over Vin range
—
—
—
—
±0.4
±0.2
1
±0.8
±0.4
—
%Vo
%Vo
%Vo
0.1 ≤ Io ≤ 3.0A
Vin = Vin min, Io = 3.0A
Transient Response
(with 100µF output cap)
ttr
50% load change
Vo over/undershoot
100
5.0
—
µSec
%Vo
Efficiency
η
Vin = 9V, Io = 3.0A
—
80
—
%
Switching Frequency
ƒo
Over Vin and Io ranges
700
750
800
kHz
Absolute Maximum
Operating Temperature Range
Ta
—
-40
—
+70
°C
Recommended Operating
Temperature Range
Ta
Free Air Convection, (40-60LFM)
Over Vin and Io ranges
-40
—
+70**
°C
Thermal Resistance
Storage Temperature
Mechanical Shock
Mechanical Vibration
θja
Ts
—
—
Free Air Convection, (40-60LFM)
—
—
35
—
°C/W
°C
-40
—
—
+125
—
Per Mil-STD-883D, Method 2002.3
500
G’s
Per Mil-STD-883D, Method 2007.2,
20-2000 Hz, soldered in a PC board
—
—
10
11
—
—
G’s
Weight
—
—
Grams
*
ISR will operate down to no load with reduced specifications.
** See Thermal Derating chart.
Note: The 78HT300 Series requires a 100µF electrolytic or tantalum output capacitor for proper operation in all applications.
Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com