TECHNICAL DATA
3.0 A, 15 V, Step-Down
Switching Regulator
IL2576-xx
The IL2576 series of regulators are monolithic integrated
circuits ideally suited for easy and convenient design of a step–
down switching regulator (buck converter). All circuits of this series
are capable of driving a 3.0 A load with excellent line and load
regulation. These devices are available in fixed output voltages of
TO-220-5L
3.3 V, 5.0 V, 12 V, 15 V, and an adjustable output version.
These regulators were designed to minimize the number of
external components to simplify the power supply design. Standard
series of inductors optimized for use with the IL2576 are offered by
several different inductor manufacturers. Since the IL2576
converter is a switch–mode power supply, its efficiency is
TO-263-5L
significantly higher in comparison with popular three–terminal
linear regulators, especially with higher input voltages. In many
cases, the power dissipated is so low that no heatsink is required
or its size could be reduced dramatically.
A standard series of inductors optimized for use with the
ORDERING INFORMATION
IL2576 are available from several different manufacturers. This
feature greatly simplifies the design of switch–mode power
IL2576S
TO-220-5L
supplies. The IL2576 features include a guaranteed ±4% tolerance
IL2576D2
TO-263-5L
on output voltage within specified input voltages and output load
conditions, and ±10% on the oscillator frequency (±2% over 0°C to
T
A
= -40° to 125° C for all packages
125°C). External shutdown is included, featuring 80
㎂
(typical)
standby current. The output switch includes cycle–by–cycle current
limiting, as well as thermal shutdown for full protection under fault conditions.
Features
•
•
•
•
•
•
•
•
•
•
3.3 V, 5.0 V, 12 V, 15 V, and Adjustable Output Versions
Adjustable Version Output Voltage Range, 1.23 to 37 V ±4%
Maximum Over Line and Load Conditions
Guaranteed 3.0 A Output Current
Wide Input Voltage Range
Requires Only 4 External Components
52 kHz Fixed Frequency Internal Oscillator
TTL Shutdown Capability, Low Power Standby Mode
High Efficiency
Uses Readily Available Standard Inductors
Thermal Shutdown and Current Limit Protection
Pin connections
1. Vin
2. Output
3. Ground
4. Feedback
5. ON/OFF
Applications
•
•
•
•
•
•
Simple High–Efficiency Step–Down (Buck) Regulator
Efficient Pre–Regulator for Linear Regulators
On–Card Switching Regulators
Positive to Negative Converter (Buck–Boost)
Negative Step–Up Converters
Power Supply for Battery Chargers
Rev. 02
IL2576-xx
Typical Application (Fixed Output Voltage Versions)
Figure 1.
Representative Block Diagram and Typical Application
This device contains 162 active transistors.
Figure 2.
ABSOLUTE MAXIMUM RATINGS
(Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.)
Rating
Maximum Supply Voltage
ON/OFF Pin Input Voltage
Output Voltage to Ground (Steady–State)
Power Dissipation
TO–220, 5–Lead
Thermal Resistance, Junction–to–Ambient
Thermal Resistance, Junction–to–Case
TO–263, 5–Lead (D2PAK)
Thermal Resistance, Junction–to–Ambient
Thermal Resistance, Junction–to–Case
Storage Temperature Range
Minimum ESD Rating (Human Body Model:
C = 100 pF, R = 1.5 kΩ)
Lead Temperature (Soldering, 10 seconds)
Maximum Junction Temperature
Vin
–
–
P
D
R
θJA
R
θJC
P
D
R
θJA
R
θJC
Tstg
–
–
T
J
Symbol
Value
45
–0.3 V
≤
V
≤
+Vin
–1.0
Internally Limited
65
5.0
Internally Limited
70
5.0
–65 to +150
2.0
260
150
V
V
V
W
°C/W
°C/W
W
°C/W
°C/W
°C
kV
°C
°C
Unit
Rev. 02
IL2576-xx
OPERATING RATINGS
(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.)
Rating
Operating Junction Temperature Range
Supply Voltage
Symbol
T
J
Vin
Value
–40 to +125
40
Unit
°C
V
SYSTEM PARAMETERS
[Note 1]
ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, V
in
= 12 V for the 3.3 V, 5.0 V, and Adjustable version, V
in
= 25 V for the 12 V version, and V
in
= 30 V for
the 15 V version. I
Load
= 500 mA, T
J
= 25
°
C, for min/max values T
J
is the operating junction temperature range that applies [Note 2],
unless otherwise noted.)
Characteristics
IL2576–3.3
([Note 1] Test Circuit Figure 3)
Output Voltage
Output Voltage (6.0 V
≤
Vin
≤
40 V, 0.5 A
≤
I
Load
≤
3.0 A)
T
J
= 25°C
T
J
= –40 to +125°C
Efficiency (Vin = 12 V, I
Load
= 3.0 A)
IL2576–5
[Note 1]
Output Voltage
Output Voltage (8.0 V
≤
Vin
≤
40 V, 0.5 A
≤
ILoad
≤
3.0 A)
T
J
= 25°C
T
J
= –40 to +125°C
Efficiency (Vin = 12 V, I
Load
= 3.0 A)
IL2576–12
[Note 1]
Output Voltage
Output Voltage (15.0 V
≤
Vin
≤
40 V, 0.5 A
≤
I
Load
≤
3.0 A)
T
J
= 25°C
T
J
= –40 to +125°C
Efficiency (Vin = 12 V, I
Load
= 3.0 A)
IL2576–15
[Note 1]
Output Voltage
Output Voltage (18 V
≤
Vin
≤
40 V, 0.5 A
≤
I
Load
≤
3.0 A)
T
J
= 25°C
T
J
= –40 to +125°C
Efficiency (Vin = 12 V, I
Load
= 3.0 A)
IL2576 ADJUSTABLE VERSION
[Note 1]
Feedback Voltage (Vin = 12 V, I
Load
= 0.5 A, Vout = 5.0 V, T
J
= 25°C)
Feedback Voltage (8.0 V
≤
Vin
≤
40 V, 0.5 A
≤
I
Load
≤
3.0 A,
Vout = 5.0 V)
T
J
= 25°C
T
J
= –40 to +125°C
Efficiency (Vin = 12 V, I
Load
= 3.0 A, Vout = 5.0 V)
Symbol
Vout
Vout
Min
3.234
3.168
3.135
Max
3.366
3.432
3.465
-
5.1
5.2
5.25
-
12.24
12.48
12.6
-
15.3
15.6
15.75
-
1.243
Unit
V
V
η
Vout
Vout
65
4.9
4.8
4.75
%
V
V
η
Vout
Vout
67
11.76
11.52
11.4
%
V
V
η
Vout
Vout
78
14.7
14.4
14.25
%
V
V
η
Vout
Vout
78
1.217
%
V
V
η
1.193
1.18
67
1.267
1.28
-
%
1. External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system
performance.
When the IL2576 is used as shown in the test circuit, system performance will be as shown in system parameters section .
Rev. 02
IL2576-xx
2. Tested junction temperature range for the IL2576: T
low
= –40
°
C T
high
= +125
°
C
DEVICE PARAMETERS
ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, V
in
= 12 V for the 3.3 V, 5.0 V, and Adjustable version, V
in
= 25 V
for the 12 V version, and V
in
= 30 V for the 15 V version. I
Load
= 500 mA, T
J
= 25
°
C, for min/max values T
J
is the
operating junction temperature range that applies [Note 2], unless otherwise noted.)
Characteristics
ALL OUTPUT VOLTAGE VERSIONS
Feedback Bias Current (Vout = 5.0 V [Adjustable Version
Only])
T
J
= 25°C
T
J
= –40 to +125°C
Oscillator Frequency [Note 3]
T
J
= 25°C
T
J
= –40 to +125°C
Saturation Voltage (Iout = 3.0 A [Note 4])
T
J
= 25°C
T
J
= –40 to +125°C
Max Duty Cycle (“on”) [Note 5]
Current Limit (Peak Current [Notes 3 and 4])
T
J
= 25°C
T
J
= –40 to +125°C
Output Leakage Current [Notes 6 and 7], T
J
= 25°C
Output = 0 V
Output = –1.0 V
Quiescent Current [Note 6]
T
J
= 25°C
T
J
= –40 to +125°C
Standby Quiescent Current (ON/OFF Pin = 5.0 V (“off”))
T
J
= 25°C
ON/OFF Pin Logic Input Level
Vout = 0 V
T
J
= 25°C
T
J
= –40 to +125°C
Vout = Nominal Output Voltage
T
J
= 25°C
T
J
= –40 to +125°C
ON/OFF Pin Input Current
ON/OFF Pin = 5.0 V (“off”), T
J
= 25°C
ON/OFF Pin = 0 V (“on”), T
J
= 25°C
Symbol
I
b
–
–
f
osc
V
sat
D
C
I
CL
I
L
–
42
–
–
93
Min
Max
Unit
nA
100
500
kHz
–
63
V
1.8
2.0
–
6.9
7.5
mA
2.0
30
mA
10
11
uA
200
V
%
A
4.2
3.5
–
–
–
–
–
I
Q
Istby
V
IH
V
IL
2.2
2.4
–
–
–
–
–
–
1.0
0.8
uA
30
10
I
IH
I
IL
3. The oscillator frequency reduces to approximately 18 kHz in the event of an output short or an overload which causes the regulated
output voltage to drop approximately 40% from the nominal output voltage. This self protection feature lowers the average dissipation of
the IC by lowering the minimum duty cycle from 5% down to approximately 2%.
4. Output (Pin 2) sourcing current. No diode, inductor or capacitor connected to output pin.
5. Feedback (Pin 4) removed from output and connected to 0 V.
6. Feedback (Pin 4) removed from output and connected to +12 V for the Adjustable, 3.3 V, and 5.0 V versions, and +25 V for the 12 V
and 15 V versions, to force the output transistor “off”.
7. V
in
= 40 V.
Rev. 02
IL2576-xx
Fixed Output Voltage Versions
Figure 3.
Cin – 100 mF, 75 V, Aluminium Electrolytic
Cout – 1000 mF, 25 V, Aluminium Electrolytic
D1 – Schottky, MBR360
L1 – 100 mH, Pulse Eng. PE–92108
R1 – 2.0 k, 0.1%
R2 – 6.12 k, 0.1%
Adjustable Output Voltage Versions
Figure 4.
⎛
R
⎞
V
out
=
V
ref
⎜
1.0
+
2
⎟
,
⎜
R
1
⎟
⎠
⎝
C1 = 10 nF
C2 = 1 nF
⎛
V
⎞
R
2
=
R
1
⎜
out
−
1.0
⎟
⎜
V
⎟
⎝
ref
⎠
Where Vref = 1.23 V, R1 between 1.0 k and 5.0 k
Rev. 02
