Application Notes
Mechanical Outline
For assistance or to order, call (800) 531-5782
Product Selector Guide
P T 7 8 H T 2 0 0 S e r i e s
2 AMP POSITIVE STEP-DOWN
INTEGRATED SWITCHING REGULATOR
Revised 5/15/98
• High Efficiency > 85%
• Wide Input Range
• Self-Contained Inductor
• Short-Circuit Protection
• Over-Temperature Protection
• Fast Transient Response
a maximum output current of 2.0 Amps.
The output voltage is laser trimmed
for high accuracy.
These 78 series regulators have excel-
lent line and load regulation with internal
short-circuit and over-temperature protec-
tion, and are offered in a variety of standard
output voltages. These ISRs are very flex-
ible and may be used in a wide variety of
applications.
This is the new generation of the
PT78HT200 Series wide input range
3 terminal regulators. These ISRs have
Pin-Out Information
Ordering Information
PT78HT2
XX
Y
Pin Function
1
2
3
V
in
Standard Application
GND
Vout
Output Voltage
Package Suffix
V = Vertical Mount
S = Surface Mount
H = Horizontal
Mount
33 = 3.3 Volts
05 = 5.0 Volts
53 = 5.25 Volts
65 = 6.5 Volts
Vin
Vout
1
3
PT78HT200
2
+
C1
COM
C2
COM
C1 = Optional 1µF ceramic
C2 = Required 100µF electrolytic
Pkg Style 500
Specifications
PT78HT200 SERIES
Characteristics
(Ta = 25°C unless noted)
Symbols
Io
Conditions
Min
0.1*
—
Typ
—
Max
2.0
Units
A
Output Current
Over Vin range
Vin = Vin min
0.1 ≥ Io ≥ 2.0A
Short Circuit Current
Input Voltage Range
Isc
6.0
—
Apk
Vin
Vo=3.3V
Vo=5V
9
—
—
—
15
28
28
V
V
V
9
Vo=6.5V
10.5
Output Voltage Tolerance
∆Vo
Over Vin range, Io = 2.0A
Ta = 0°C to +60°C
—
±1.0
±2.0
%Vo
Line Regulation
Load Regulation
Vo Ripple/Noise
Regline
Regload
Vn
Over Vin range
—
—
—
—
±0.4
±0.2
±1
±0.8
±0.4
—
%Vo
%Vo
%Vo
0.1 ≤ Io ≤ 2.0A
Vin = Vin min, Io = 2.0A
Transient Response
ttr
50% load change
100
5.0
—
µSec
%Vo
(with 100µF output cap)
Vo over/undershoot
Efficiency
η
Vin=9V, Io = 2.0A
Vo=5V
—
80
—
%
Switching Frequency
ƒo
Over Vin and Io ranges Vo=5V, 6.5V
Vo=3.3V
700
950
750
800
kHz
kHz
1,000
1,050
Absolute Maximum
Ta
Ta
—
-40
—
+85
°C
Operating Temperature Range
Recommended Operating
Temperature Range
Free Air Convection, (40-60LFM)
Over Vin and Io ranges
-40
—
+75**
°C
Thermal Resistance
Storage Temperature
Mechanical Shock
θja
Ts
—
—
Free Air Convection, (40-60LFM)
—
—
40
—
°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 PT78HT200 Series requires a 100µF electrolytic or tantalum output capacitor for proper operation in all applications.
16
Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com