7222

NTE7222
Integrated Circuit
Step−Down Switching Voltage Regultor
Fixed Output
Description:
The NTE7222 regulator is a monolithic integrated circuit in a 5−Lead TO220 type package that
provides all the active functions for a step−down (buck) switching regulator, capable of driving a 3A
load with excellent line and load regulation. This device offers a high−efficiency replacement for popular
three−terminal linear regulators and substantially reduces the size of the heat sink and in some cases,
no heat sink is required.
Features:
D Fixed Output: VOUT = 5V
D Guaranteed 3A Output Current
D 52kHz Fixed Frequency Internal Oscillator
D TTL Shutdown Capability, Low Power Standby Mode
D High Efficiency
D Thermal Shutdown and Current Limit Protection
Applications:
D Simple High−Efficiency Step−Down (Buck) Regulator
D Efficient Pre−Regulator for Linear Regulators
D On−Card Switching Regulator
D Positive to Negative Converter (Buck−Boost)
Absolute Maximum Ratings: (Note 1)
Maximum Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45V
ON/OFF Pin Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3V≤ V ≤ +VIN
Output Voltage to GND (Steady State) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −1V
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Internally Limited
Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +150°C
Storage Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65° to +150°C
Minimum ESD Rating (C = 100pF, R = 1.5kΩ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2kV
Lead Temperature (During Soldering, 10 sec Max) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +260°C
Typical Thermal Resistance, Junction−to−Ambient (Mounted Vertically, No External Heat Sink)
1/2” leads in a socket or PC mounted with minimum copper area . . . . . . . . . . . . . . . 65°C/W
1/4” leads soldered to a PC board containing approx 4 square inches of copper . . 45°C/W
Typical Thermal Resistance, Junction−to−Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2°C/W
Note 1. Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.
Operating Ratings indicate conditions for which the device is intended to be functional, but
do not guarantee specific performance limits. For guaranteed specifications and test conditions,
see the Electrical Characteristics.
Operating Ratings:
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40V
Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −40° ≤ TJ ≤ +125°C
Electrical Characteristics: (VIN = 12V, ILOAD = 500mA, TJ = +25°C unless otherwise specified)
Parameter
Output Voltage
Symbol
Test Conditions
VOUT
0.5A ≤ ILOAD ≤ 3A,
8V ≤ VIN ≤ 40V
TJ = −40° to +125°C
Min
Typ
Max
Unit
4.9
5.0
5.1
V
4.8
5.0
5.2
V
4.75
5.0
5.25
V
Efficiency
η
VIN = 12V, ILOAD = 3A
−
77
−
%
Oscillator Frequency
fO
Note 2
47
52
58
kHz
42
52
63
kHz
−
1.4
1.8
V
−
1.4
2.0
V
TJ = −40° to +125°C
Saturation Voltage
VSAT
IOUT = 3A, Note 3
TJ = −40° to +125°C
Maximum Duty Cycle
DC
Note 4
93
98
−
%
Current Limit
ICL
Note 2, Note 3
4.2
5.8
6.9
A
3.5
5.8
7.5
A
Output = 0V
−
−
2
mA
Output = −1V
−
7.5
30
mA
Note 5
−
5
10
mA
ON/OFF Pin = 5V (OFF)
−
50
200
μA
2.2
1.4
−
V
2.4
1.4
−
V
−
1.0
1.2
V
−
0.8
1.2
V
TJ = −40° to +125°C
Output Leakage Current
Quiescent Current
Standby Quiescent Current
IL
IQ
ISTBY
Note 5
ON/OFF Control
ON/OFF Pin Logic Input Level
VIH
VOUT = 0V
TJ = −40° to +125°C
VIL
VOUT = Nom Output
TJ = −40° to +125°C
ON/OFF Pin Input Current
IIH
ON/OFF Pin = 5V (OFF)
−
12
30
μA
IIL
ON/OFF Pin = 0V (ON)
−
0
10
μA
Note 2. The oscillator frequency reduces to approximately 11kHz in the event of an output short or
an overload which causes the regulated output voltage to drop approximately 40% from the
nominal outpu voltage. This self protection feature lowers the average power dissipation of
the IC by lowering the minimum duty cycle from 5% down to approximately 2%.
Note 3. Output pin sourcing current. No diode, inductor or capacitor connected to output.
Note 4. Feedback pin removed from output and connected to 0V.
Note 5. Feedback pin removed from output and connected to +12V to force the output transistor
OFF.
Pin Connection Diagram
(Front View)
ON/OFF
VIN
Feedback
Output
GND/Tab
.400 (10.16)
0.50 (1.27)
.110 (2.79)
.590
(15.0)
.340
(8.65)
1.035
(26.29)
Max
.067 (1.7)
1
5
.105 (2.67)