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
12
Application Notes
Mechanical Outline
Product Selector Guide
Standard Application
C1 = Optional 1µF ceramic
C2
= Required 100µF electrolytic
Pin-Out Information
Pin
Function
1
V
in
2
GND
3
V
out
Ordering Information
PT78ST1 XX Y
33
= 3.3 Volts
36
= 3.6 Volts
05
= 5.0 Volts
51
= 5.1 Volts
53
= 5.25 Volts
06
= 6.0 Volts
65
= 6.5 Volts
07
= 7.0 Volts
08
= 8.0 Volts
09
= 9.0 Volts
10
= 10.0 Volts
12
= 12.0 Volts
14
= 13.9 Volts
15
= 15.0 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
This is the new generation of
PT78ST100 Series wide input range
3 terminal regulators. These ISRs have a
maximum output current of 1.5 Amps 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, and
are offered in a variety of standard output
voltages. These ISRs are very flexible and
may be used in a wide variety of applications.
P T 7 8 S T 1 0 0 S e r i e s
Output Voltage
Specifications
Characteristics
PT78ST100 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
9
—
26
V
V
o
= 5V
9
—
38
V
V
o
= 12V
16
—
38
V
Output Voltage Tolerance
∆
V
o
Over V
in
range, I
o
=1.5A
—
±1.0
±2.0
%Vo
T
a
= 0°C to +60°C
Line Regulation
Reg
line
Over V
in
range
—
±0.2
±0.4
%Vo
Load Regulation
Reg
load
0.1
≤
I
o
≤
1.5A
—
±0.1
±0.2
%Vo
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
—
%Vo
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 PT78ST100 Series requires a 100µF electrolytic or tantalum output capacitor for proper operation in all applications.
PT78ST100
C2
+
Vout
COM
COM
Vin
C1
1
2
3
Pkg Style 500
Revised 7/15/98
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
13
W
ide Input Range Pr
oducts
DA
T
A
SHEETS
C H A R A C T E R I S T I C D A T A
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
9
13
17
21
25
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
9
12
15
18
21
24
27
30
33
36
39
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
16
19
22
25
28
31
34
37
40
PT78ST133, 3.3 VDC
(See Note 1)
PT78ST105, 5.0 VDC
(See Note 1)
PT78ST112, 12.0 VDC
(See Note 1)
Efficiency vs Output Current
Ripple vs Output Current
Thermal Derating (T
a
)
(See Note 2)
Power Dissipation vs Output Current
Efficiency - %
Ripple-(mV)
Iout-(Amps)
PD-(W
atts)
Efficiency - %
Efficiency - %
Ripple-(mV)
Ripple-(mV)
Iout-(Amps)
Iout-(Amps)
PD-(W
atts)
PD-(W
atts)
Iout-(Amps)
Iout-(Amps)
Iout-(Amps)
Iout-(Amps)
Iout-(Amps)
Iout-(Amps)
Iout-(Amps)
Iout-(Amps)
Iout-(Amps)
Vin-(Volts)
Vin-(Volts)
Vin-(Volts)
40
50
60
70
80
90
100
0
0.25
0.5
0.75
1
1.25
1.5
9.0V
12.0V
15.0V
20.0V
26.0V
Vin
40
50
60
70
80
90
100
0
0.25
0.5
0.75
1
1.25
1.5
16.0V
18.0V
24.0V
30.0V
38.0V
Vin
0
50
100
150
200
250
300
0
0.25
0.5
0.75
1
1.25
1.5
38.0V
30.0V
24.0V
18.0V
16.0V
Vin
0
20
40
60
80
100
0
0.25
0.5
0.75
1
1.25
1.5
26.0V
20.0V
15.0V
12.0V
9.0V
Vin
0
0.5
1
1.5
2
2.5
3
0
0.25
0.5
0.75
1
1.25
1.5
38.0V
30.0V
24.0V
18.0V
16.0V
Vin
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0
0.25
0.5
0.75
1
1.25
1.5
26.0V
20.0V
15.0V
12.0V
9.0V
Vin
85°C
60°C
70°C
85°C
85°C
70°C
Note 1:
All data listed in the above graphs, except for derating data, has been developed from actual products tested at 25°C. This data is considered typical data for the ISR.
Note 2:
Thermal derating graphs are developed in free air convection cooling of 40-60 LFM. (See Thermal Application Notes.)
40
50
60
70
80
90
100
0
0.25
0.5
0.75
1
1.25
1.5
9.0V
12.0V
18.0V
24.0V
30.0V
38.0V
Vin
0
30
60
90
120
150
0
0.25
0.5
0.75
1
1.25
1.5
38.0V
30.0V
24.0V
18.0V
12.0V
9.0V
Vin
0
0.5
1
1.5
2
2.5
0
0.25
0.5
0.75
1
1.25
1.5
38.0V
30.0V
24.0V
18.0V
12.0V
9.0V
Vin
60°C
70°C
P T 7 8 S T 1 0 0 S e r i e s
60°C
Efficiency vs Output Current
Efficiency vs Output Current
Ripple vs Output Current
Ripple vs Output Current
Thermal Derating (T
a
)
(See Note 2)
Thermal Derating (T
a
)
(See Note 2)
Power Dissipation vs Output Current
Power Dissipation vs Output Current
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1999, Texas Instruments Incorporated