PT78ST200 Datasheet, PDF (1/3 Pages) Texas Instruments – 12V 2 AMP POSITIVE STEP-DOWN INTEGRATED SWITCHING REGULATOR

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PT78ST200 S e r i e s
12V 2 AMP POSITIVE STEP-DOWN
INTEGRATED SWITCHING REGULATOR
Application Notes
Mechanical Outline
Product Selector Guide
Revised 5/15/98
• High Efficiency > 87%
• Wide Input Range
• Aluminum Heatsink for
Applications with Airflow
• Self-Contained Inductor
• Short Circuit Protection
• Over-Temperature Protection
• Pin Compatible with Linear
3-Terminal, “78” Series Regulators
• Small Footprint
The Power Trends’ PT78ST200 is
a new 3-terminal Integrated Switching
Regulator (ISR) that can supply up to 24
watts of regulated 12V power. With a
surge capability of 3 Amps and an out-
put voltage that is laser trimmed, it is
ideal for inductive load applications
such as disk drive motors.
Standard Application
Vin
C1
COM
1 _PT78ST200 3
Vout
+
2
C2
COM
Pin-Out Information
Pin Function
1
V_in
2 GND
3
V_out
C₁ = Optional 1µF ceramic
C₂ = Required 100µF electrolytic
Specifications
Pkg Style 600
Characteristics
(T_a = 25°C unless noted)
Output Current
Short Circuit Current
Input Voltage Range
Output Voltage Tolerance
Line Regulation
Load Regulation
Vo Ripple/Noise
Transient Response
(with 100µF output cap)
Efficiency
Switching Frequency
Absolute Maximum
Operating Temperature Range
Recommended Operating
Temperature Range
Thermal Resistance
Storage Temperature
Mechanical Shock
Mechanical Vibration
Weight
Symbols
I_o
Isc
Vin
∆Vo
Regline
Regload
Vn
ttr
η
ƒo
Ta
T_a
θja
Ts
—
—
—
Conditions
Over V_in range
With forced air cooling
Vin = Vin min
0.1 ≤ Io ≤ 2.0A
Over Vin range, Io= 2.0A
T_a= 0°C to +60°C
Over Vin range
0.1 ≤ Io ≤ 2.0A
Vin=17V, Io=2.0A, Vo=12V
50% load change
V_o over/undershoot
Vin=17V, Io=2.0A
Over Vin and Io ranges
—
Free Air Convection, (40-60LFM)
at Vin= 24V, Io=2A
Free Air Convection, (40-60LFM)
—
Per Mil-STD-883D, Method 2002.3
Per Mil-STD-883D, Method 2007.2,
20-2000 Hz, Soldered in a PC board
—
*ISR will operate down to no load with reduced specifications.
**See Thermal Derating chart.
Note: The PT78ST200 Series requires a 100µF electrolytic or tantalum output capacitor for proper operation in all applications.
Ordering Information
PT78ST2 XX Y
Output Voltage
12 = 12.0 Volts
Package Suffix
V = Vertical Mount
PT78ST200 SERIES
Min
Typ
0.1*
—
—
5.0
16
—
—
±1.0
—
±0.4
—
±0.2
—
120
—
100
—
5.0
—
87
0.95
1.0
-40
—
-40
—
—
35
-40
—
—
500
—
10
—
11
Max
2.0
—
28
±2.0
±0.8
±0.4
—
—
—
—
1.05
+65
+55**
—
+125
—
—
—
Units
A
Apk
V
%Vo
%Vo
%Vo
mVpp
µSec
%V_o
%
MHz
°C
°C
°C/W
°C
G’s
G’s
Grams
18
Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 [phone] Fax: [phone] http://www.powertrends.com