For assistance or to order, call (800) 531-5782
P T5 1 2 0 S e r i e s
SLTS080
(Revised 6/4/98)
1 AMP LOW VOLTAGE INPUT
INTEGRATED SWITCHING REGULATOR
The PT5120 series is a low voltage in-
• LowVoltageInput(7V)
• 85% Efficiency
• Internal Short-Circuit Protection
• Over-Temperature Protection
• Laser-Trimmed Output Voltage
put (typically 7V) version of Power
Trends’ easy-to-use, 1A positive step-
down, 3-terminal Integrated Switching
Regulators (ISRs). These ISRs are de-
signed with premium low-threshold
FETs for those power regulation appli-
cations requiring very low input/output
voltage differentials such as battery
powered equipment.
Pin-Out Information
Ordering Information
PT 5121! =+ 5 Volts
PT 5123! =+ 3.3Volts
PT Series Suffix
Case/Pin
Configuration
(PT1234X)
Pin
Function
Vin
1
Vertical Through-Hole
N
A
C
GND
Vout
2
Horizontal Through-Hole
Horizontal Surface Mount
Standard Application
3
Vin
Vout
GND
1
3
PT5120
2
Pkg Style 100
+
C1
GND
C2
PT5120
C1 = Optional 1µF ceramic
C2 = Required 100µF electrolytic
Specifications
PT5120 SERIES
Characteristics
(T =25°C unless noted)
Symbols
Io
Conditions
Min
0.1*
—
Typ
—
Max
1.0
—
Units
a
Output Current
Over Vin range
Vin = Vin min
0.1 ≤ Io ≤ 1.0 A
A
Short Circuit Current
Input Voltage Range
Isc
3.5
—
Apk
Vin
Vo =
Vo =
3.3V7
5V7
26
38
V
V
Output Voltage Tolerance
∆Vo
Over Vin Range, Io = 1.0 A
Ta = 0°C to +60°C
—
1.5
3.0
%Vo
Line Regulation
Load Regulation
Vo Ripple/Noise
Regline
Regload
Vn
Over Vin range
—
—
—
0.5
0.5
2
1.0
1.0
—
%Vo
%Vo
%Vo
0.1 ≤ Io ≤ 1.0 A
Vin=Vin min, Io=1.0 A
Transient Response
with Co = 100µF
ttr
25% load change
—
—
100
5.0
200
—
µSec
%Vo
Vos
Vo over/undershoot
Efficiency
η
Vin=9V, Io=0.5A, Vo=3.3V—
Vin=9V, Io=0.5A, Vo=5V—
82
85
—
%
—
%
Switching Frequency
ƒo
Ta
Ta
θja
Ts
Over Vin and Io ranges, Vo=
Vo =
3.3V575
>5V500
725
650
875
800
kHz
°C
Absolute Maximum
-20
—
+85
Operating Temperature Range
Recommended Operating
Temperature Range
Free Air Convection, Vo=
3.3V-20
5V-20
—
—
+80**
+80**
°C
(40-60LFM)
Vo=
Thermal Resistance
Free Air Convection Vo =
(40-60LFM) Vo =
3.3V—
5V—
45
50
—
—
°C/W
°C
Storage Temperature
Mechanical Shock
-40
—
+125
Per Mil-STD-883D, Method 2002.3
—
500
—
G’s
1 msec, Half Sine, mounted to a fixture
Mechanical Vibration
Per Mil-STD-883D, Method 2007.2
20-2000 Hz, Soldered in a PC board
—
—
5
—
—
G’s
Weight
4.5
grams
* ISR will operate down to no load with reduced specifications.
**See Thermal Derating chart.
Note: The PT5120 Series requires a 100µF electrolytic or tantalum output capacitor for proper operation in all applications.
2
Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.ti.com/powertrends