Replacement of
LM2576 Series
MIK2576 Series
Simple Switcher (3A Step-
Down Voltage Regulator)
May 2001 - revised July 2002
Description
The MIK2576 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching
regulator, capable of driving 3A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V,
5V, 12V, 15V, and an adjustable output versions. Requiring a minimum number of external components, these regulators are simple to
use and include internal frequency compensation and a fixed-frequency oscillator. The MIK2576 series offers a high-efficiency
replacement for popular three-terminal linear regulators. It substantially reduces the size of the heat sink, and in some cases no heat
sink is required. A standard series of inductors optimized for use with the MIK2576 are available from several different manufacturers.
This feature greatly simplifies the design of switch-mode power supplies. Other features include a guaranteed
4% tolerance on output
voltage within specified input voltages and output load conditions, and
10% on the oscillator frequency. External shutdown is included,
featuring 50
A (typical) standby current. The output switch includes cycle-by-cycle current limiting, as well as thermal shutdown for full
protection under fault conditions.
Note: The MIK2576HV is not produced yet.
Features
3.3V, 5V, 12V, 15V, and adjustable output versions
Adjustable version output voltage range
1.23V to 37V (57V for HV version)
4% max over line
and load conditions
Guaranteed 3A output current
Wide input voltage range, 40V up to 60V for HV
version
Requires only 4 external components
52 kHz fixed frequency oscillator
TTL shutdown capability, low power standby mode
High efficiency
Uses readily available standard inductors
Thermal shutdown and current limit protection
Applications
Simple high-efficiency step-down (buck) regulator
Efficient pre-regulator for linear regulators
On-card switching regulators
Positive to negative converter (Buck-Boost)
Typical application
Figure 1.(Fixed Output Voltage Versions)
MIK2576/
7V - 40V
(60V for HV)
UNREGULATED
DC INPUT
MIK2576HV-
5.0
+V
IN
+5V
REGULATED
OUTPUT
3A LOAD
1
+
C
IN
3
GND
ON/OFF
OUTPUT
4
FEEDBACK
L1
2
100 H
+
C
5
OUT
D1
100
F
1000 F
1N5822
Page 1 of 9
Replacement of
LM2576 Series
MIK2576 Series
Simple Switcher (3A Step-
Down Voltage Regulator)
May 2001 - revised July 2002
Block Diagram
+
C
IN
C
OUT
FEED-
BACK
+
1
4
+
-
-
+
DRIVER
1.23V
BAND-GAP
REFERENCE
52kHZ
OSCILLATOR
RESET
THERMAL
SHUTDOWN
CURRENT
LIMIT
3
2
L1
L
O
A
D
INTERNAL
REGULATOR
ON/OFF
5
R2
R1
1.0k
FIXED GAIN
ERROR AMP
COMPARATOR
3 AMP
SWITCH
OUTPUT
GND
V
OUT
D1
ON/OFF
V
IN
UNREGULATED
DC INPUT
3.3V, R2 =1.7K
5V, R2 = 3.1K
12V, R2 = 8.84K
15V, R2 =11.3K
For ADJ, Version
R1 = Open, R2 =0
Ordering information
Output Voltage, V
Temperature
Range
3.3 5.0 12 15 ADJ
Package Type
MIK2576HVS-3.3 MIK2576HVS-5.0 MIK2576HVS-12 MIK2576HVS-15 MIK2576HVS-ADJ
MIK2576S-3.3 MIK2576S-5.0 MIK2576S-12 MIK2576S-15 MIK2576S-ADJ
TO-263
MIK2576HVT-3.3 MIK2576HVT-5.0 MIK2576HVT-12 MIK2576HVT-15 MIK2576HVT-ADJ
-40
C T
A
125C
MIK2576T-3.3 MIK2576T-5.0 MIK2576T-12 MIK2576T-15 MIK2576T-ADJ
TO-220
Page 2 of 9
Replacement of
LM2576 Series
MIK2576 Series
Simple Switcher (3A Step-
Down Voltage Regulator)
May 2001 - revised July 2002
Absolute Maximum Ratings
(Note 1)
Parameter Maximum
Units
Maximum Supply Voltage
MIK2576
MIK2576HV
45
63
ON/OFF Pin Input Voltage
-0.3V
V +V
IN
V
Output Voltage to Ground (Steady State)
-1
V
Power Dissipation
Internally Limited
W
Storage Temperature Range
-65 to +150
C
Maximum Junction Temperature
150
C
Minimum ESD Rating (C= 100pF, R = 1.5 k
)
2 kV
Lead Temperature (Soldering, 10 Seconds)
260
C
Operating Ratings
Parameter Value
Units
Temperature Range
MIK2576/ MIK2576HV
-40
T
J
+125
C
Supply Voltage
MIK2576
MIK2576HV
40
60
V
Electrical Characteristics MIK2576-3.3, MIK2576HV-3.3
Specifications with standard type face are for T
J
= 25
C, and those with boldface type apply over full Operating Temperature Range.
MIK2576-3.3
MIK2576HV-3.3
Symbol Parameter
Conditions
Typ Limit
(Note 2)
Units
(Limits)
SYSTEM PARAMETERS (Note 3) Test Circuit Figure 2
V
OUT
Output Voltage
V
IN
=12V, I
LOAD
=0.5A
Circuit of Figure 2
3.3
3.234
3.366
V
V(Min)
V(Max)
V
OUT
Output Voltage
MIK2576
6V
V
IN
40V, 0.5A I
LOAD
3A
Circuit of Figure 2
3.3
3.168/3.135
3.432/3.465
V
V(Min)
V(Max)
V
OUT
Output Voltage
MIK2576HV
6V
V
IN
60V, 0.5A I
LOAD
3A
Circuit of Figure 2
3.3
3.168/3.135
3.450/3.482
V
V(Min)
V(Max)
Efficiency V
IN
=12V, I
LOAD
=3A
75
%
Electrical Characteristics MIK2576-5.0, MIK2576HV-5.0
Specifications with standard type face are for T
J
= 25
C, and those with boldface type apply over full Operating Temperature Range.
MIK2576-5.0
MIK2576HV-5.0
Symbol Parameter
Conditions
Typ Limit
(Note 2)
Units
(Limits)
SYSTEM PARAMETERS (Note 3) Test Circuit Figure 2
V
OUT
Output Voltage
V
IN
=12V, I
LOAD
=0.5A
Circuit of Figure 2
5.0
4.900
5.100
V
V(Min)
V(Max)
V
OUT
Output Voltage
MIK2576
0.5A
I
LOAD
3A,
8V
V
IN
40V
Circuit of Figure 2
5.0
4.800/4.750
5.200/5.250
V
V(Min)
V(Max)
V
OUT
Output Voltage
MIK2576HV
0.5A
I
LOAD
3A,
8V
V
IN
60V
Circuit of Figure 2
5.0
4.800/4.750
5.225/5.275
V
V(Min)
V(Max)
Efficiency V
IN
=12V, I
LOAD
=3A
77
%
Page 3 of 9
Replacement of
LM2576 Series
MIK2576 Series
Simple Switcher (3A Step-
Down Voltage Regulator)
May 2001 - revised July 2002
Electrical Characteristics MIK2576-12, MIK2576HV-12
Specifications with standard type face are for T
J
= 25
C, and those with boldface type apply over full Operating Temperature Range.
MIK2576-12
MIK2576HV-12
Symbol Parameter
Conditions
Typ Limit(Note 2)
Units
(Limits)
SYSTEM PARAMETERS (Note 3) Test Circuit Figure 2
V
OUT
Output Voltage
V
IN
=25V, I
LOAD
=0.5A
Circuit of Figure 2
12
11.76
12.24
V
V(Min)
V(Max)
V
OUT
Output Voltage
MIK2576
0.5A
I
LOAD
3A,
15V
V
IN
40V
Circuit of Figure 2
12
11.52/11.40
12.48/12.60
V
V(Min)
V(Max)
V
OUT
Output Voltage
MIK2576HV
0.5A
I
LOAD
3A,
15V
V
IN
60V
Circuit of Figure 2
12
11.52/11.40
12.54/12.66
V
V(Min)
V(Max)
Efficiency V
IN
=15V, I
LOAD
=3A
88
%
Electrical Characteristics MIK2576-15, MIK2576HV-15
Specifications with standard type face are for T
J
= 25
C, and those with boldface type apply over full Operating Temperature Range.
MIK2576-15
MIK2576HV-15
Symbol Parameter
Conditions
Typ Limit
(Note 2)
Units
(Limits)
SYSTEM PARAMETERS (Note 3) Test Circuit Figure 2
V
OUT
Output Voltage
V
IN
=25, I
LOAD
=0.5A
Circuit of Figure 2
15
14.70
15.30
V
V(Min)
V(Max)
V
OUT
Output Voltage
MIK2576
0.5A
I
LOAD
3A,
18
V
IN
40V
Circuit of Figure 2
15
14.40/14.25
15.60/15.75
V
V(Min)
V(Max)
V
OUT
Output Voltage
MIK2576HV
0.5A
I
LOAD
3A,
18
V
IN
60V
Circuit of Figure 2
15
14.40/14.25
15.68/15.83
V
V(Min)
V(Max)
Efficiency V
IN
=18V, I
LOAD
=3A
88
%
Electrical Characteristics MIK2576-ADJ, MIK2576HV-ADJ
Specifications with standard type face are for T
J
= 25
C, and those with boldface type apply over full Operating Temperature Range.
MIK2576-ADJ
MIK2576HV-ADJ
Symbol Parameter
Conditions
Typ Limit(Note 2)
Units
(Limits)
SYSTEM PARAMETERS (Note 3) Test Circuit Figure 2
V
OUT
Feedback Voltage
V
IN
=12V, I
LOAD
=0.5A,
V
OUT
=5V
Circuit of Figure 2
1.230
1.217
1.243
V
V(Min)
V(Max)
V
OUT
Feedback Voltage
MIK2576
0.5A
I
LOAD
3A , 8V V
IN
40V
V
OUT
=5V
Circuit of Figure 2
1.230
1.193/1.180
1.267/1.280
V
V(Min)
V(Max)
V
OUT
Feedback Voltage
MIK2576HV
0.5A
I
LOAD
3A, 8V V
IN
60V,
V
OUT
=5V
Circuit of Figure 2
1.230
1.193/1.180
1.273/1.286
V
V(Min)
V(Max)
Efficiency V
IN
=12V, I
LOAD
=3A, V
OUT
=5V
77
%
Page 4 of 9
Replacement of
LM2576 Series
MIK2576 Series
Simple Switcher (3A Step-
Down Voltage Regulator)
May 2001 - revised July 2002
All Output Voltage Versions
Electrical Characteristics
Specifications with standard type face are for T
J
= 25
C, and those with boldface type apply over full Operating Temperature Range.
Unless otherwise specified, V
IN
=12V for the 3.3V, 5V, and Adjustable version, V
IN
=25V for the 12V version, and V
IN
=30V for the 15V
version, , I
LOAD
=500mA.
MIK2576-XX
MIK2576HV-XX
Units
(Limits)
Symbol Parameter
Conditions
Typ Limit
(Note 2)
DEVICE PARAMETERS
I
b
Feedback Bias Current
V
OUT
=5V (Adjustable Version Only)
50
100/500 nA
f
O
Oscillator Frequency
(Note 8)
52
47/42
58/63
kHz
kHz(Min)
kHz(Max)
V
SAT
Saturation Voltage
I
OUT
=3A (Note 4)
1.4
1.8/2.0
V
V(Max)
DC
Max Duty Cycle (ON)
(Note 5)
98
93
%
%(Min)
I
CL
Current Limit
(Notes 4, 8)
5.8
4.2/3.5
6.9/7.5
A
A(Min)
A(Max)
I
L
Output Leakage Current
(Notes 6, 7): Output = 0V
Output = -1V
Output = -1V
7.5
2
30
mA(Max)
mA
mA(Max)
I
Q
Quiescent Current
(Note 6)
5
10
mA
mA(Max)
I
STBY
Standby Quiescent Current
___
ON/OFF Pin = 5V (OFF)
50
200
A
A(Max)
___
ON/OFF CONTROL
V
IH
V
OUT
= 0V
1.4
2.2/2.4
V(Min)
V
IL
__
ON/OFF Pin
Logic Input Level
V
OUT
= Nominal Output Voltage
1.2
1.0/0.8
V(Max)
I
IH
__
ON/OFF Pin = 5V (OFF)
12
30
A
A(Max)
I
IL
__
ON/OFF Pin Input
Current
__
ON/OFF Pin = 0V (ON)
0
10
A
A(Max)
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.
Note 2: All limits guaranteed at room temperature (standard type face) and at temperature extremes (bold type face).
Note 3: External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system
performance. When the MIK2576/MIK2576HV is used as shown in the Figure 2 test circuit, system performance will be as
shown in system parameters section of Electrical Characteristics.
Note 4: Output pin sourcing current. No diode, inductor or capacitor connected to output.
Note 5: Feedback pin removed from output and connected to 0V.
Note 6: Feedback pin removed from output and connected to +12V for the Adjustable, 3.3V, and 5V, versions, and +25V for the 12V
and 15V versions, to force the output transistor OFF.
Note 7: V
IN
=40V (60V for high voltage version).
Note 8: The oscillator frequency reduces to approximately 11 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 protections feature lowers the
average power dissipation of the IC by lowering the minimum duty cycle from 5% down to approximately 2%.
Page 5 of 9
Replacement of
LM2576 Series
MIK2576 Series
Simple Switcher (3A Step-
Down Voltage Regulator)
May 2001 - revised July 2002
Typical Performance Characteristics
(Circuit of Figure 2)
V
IN
=20V
I
LOAD
= 500mA
Normalized at
T
J
=25C
I
LOA D
= 500mA
T
J
=25C
I
LOA D
= 3A
I
LOA D
= 1A
I
LOAD
= 200mA
L
1
= 150 H
R
IND
= 0.1
3.3V, 5V & ADJ
12V & 15V
JUNCTION TEMPERATURE (C)
INPUT VOLTAGE (V)
JUNCTION TEMPERATURE (C)
O
U
T
P
U
T
V
O
L
T
A
G
E
C
H
A
N
G
E
(
)
O
U
T
P
U
T
V
O
L
T
A
G
E
C
H
A
N
G
E
(%
)
I
N
P
U
T
-
O
U
T
P
U
T
D
I
F
F
E
R
E
N
T
I
A
L
(
V
)
Normalized Output Voltage
Line Regulation
Dropout Voltage
V
IN
= 40V
V
OUT
= 5V
Measured at
Ground Pin
T
J
=25C
V
IN
= 25V
V
IN
=12 V
V
ON/OFF
= 5V
I
LOAD
= 3A
I
LOAD
= 200mA
JUNCTION TEMPERATURE (C)
INPUT VOLTAGE (V)
JUNCTION TEMPERATURE (C)
S
T
A
N
D
B
Y
Q
U
I
E
S
C
E
N
T
C
U
R
R
E
N
T
(
A
)
Q
U
I
E
S
C
E
N
T
C
U
R
R
E
N
T
(
m
A
)
O
U
T
P
U
T
C
U
R
R
E
N
T
(
A
)
Standby
Quiescent Current
Quiescent Current
Current Limit
T
J
=25C
V
IN
= 40V
I
LOAD
= 3A
I
LOA D
= 200mA
V
IN
= 12V
Normalized at 25C
I
LOA D
= 200mA
I
LOA D
= 3A
-55C
25C
150C
15V OUT
5V
S
A
T
U
R
A
T
I
O
N
V
O
L
T
A
G
E
C
H
A
N
G
E
(
)
SWITCH CURRENT (A)
E
F
F
I
C
I
E
N
C
Y
(%
)
INPUT VOLTAGE (V)
F
E
E
D
B
A
C
K
V
O
L
T
A
G
E
C
H
A
H
G
E
(
m
V
)
JUNCTION TEMPERATURE (C)
Switch Saturation
Voltage
Efficiency
Oscilator Frequency
V
OUT
1.23V
I
LOAD
= 500mA
I
LOAD
= 500mA
Adjustable Version Only
Adjustable Version Only
V
IN
= 7V
V
IN
= 40V
I
LOAD
= 500mA
V
IN
= 7V
Adjustable Version Only
V
IN
= 40V
DUTY CYCLE (%)
JUNCTION TEMPERATURE (C)
Q
U
I
E
S
C
E
N
T
C
U
R
R
E
N
T
(
m
A
)
O
U
T
P
U
T
C
U
R
R
E
N
T
(
A
)
Minimum Operating Voltage
Quiescent Current
vs Duty Cycle
Feedback Voltage
vs Duty Cycle
I
N
P
U
T
V
O
L
T
A
G
E
(
V
)
DUTY CYCLE (%)
Page 6 of 9
Replacement of
LM2576 Series
MIK2576 Series
Simple Switcher (3A Step-
Down Voltage Regulator)
May 2001 - revised July 2002
Adjustable Version Only
JA
= 32C/W
JA
= 37C/W
JA
= 50C/W
JA
= 73C/W
Maximum Power Dissipation
(TO-263)
Feedback Pin Current
P
O
W
E
R
D
I
S
S
I
P
A
T
I
O
N
(
W
)
AMBIENT TEMPERATURE (C)
F
E
E
D
B
A
C
K
P
I
N
C
U
R
R
E
N
T
(
n
A
)
JUNCTION TEMPERATURE (C)
Switching Waveforms
Load Transient Response
5
s/div
A
B
C
D
100
s/div
Output
Voltage
Change
Load
Current
V
OUT
=15V
A: Output Pin Voltage, 50V/div
B: Output Pin Current, 2A/div
C: Inductor Current, 2A/div
D: Output Ripple Voltage, 50mV/div,
AC-Coupled
Horizontal Time Base: 5
s/div
Page 7 of 9
Replacement of
LM2576 Series
MIK2576 Series
Simple Switcher (3A Step-
Down Voltage Regulator)
May 2001 - revised July 2002
Test Circuit and Layout Guidelines
As in any switching regulator, layout is very important. Rapidly switching currents associated with wiring inductance generate voltage
transients which can cause problems. For minimal inductance and ground loops, the length of the leads indicated by heavy lines should
be kept as short as possible.
Single-point grounding (as indicated) or ground plane construction should be used for best results. When using the Adjustable version,
physically locate the programming resistors near the regulator, to keep the sensitive feedback wiring short.
Fixed Output Voltage Versions
(Figure 2a)
V
IN
UNREGULATED
DC INPUT
MIK2576HV-
FIXED OUTPUT
+V
IN
L
O
A
D
1
+
C
IN
3
GND
ON/OFF
OUTPUT
4
L1
100 H
D1
MBR360
C
OUT
1000 F
100 F
FEEDBACK
5
+
2
V
OUT
C
IN
-- 100
F, 75V, Aluminum Electrolytic
C
OUT
--1000
F, 25V, Aluminum Electrolytic
D1 -- Schottky, MBR360
L
1
-- 100
H, Pulse Eng. PE-92108
R
1
-- 2k, 0.1%
R
2
-- 6.12k, 0.1%
Adjustable Output Voltage Version
(Figure 2b)
7V -60V
UNREGULATED
DC INPUT
MIK2576HV-
ADJ
+V
IN
L
O
A
D
1
+
C
IN
3
GND
ON/OFF
OUTPUT
4
L1
100 H
D1
MBR360
C
OUT
1000 F
100 F
FEEDBACK
5
+
2
V
OUT
5.00V
R2
R1
)
R
R
1
(
V
V
1
2
REF
OUT
+
=
)
1
V
V
(
R
R
REF
OUT
1
2
-
=
where V
REF
= 1.23V, R1 between 1k and 5k
Page 8 of 9
Replacement of
LM2576 Series
MIK2576 Series
Simple Switcher (3A Step-
Down Voltage Regulator)
May 2001 - revised July 2002
Pad location MIK2576
Chip Size 3.95x2.65mm
Pad Location Coordinates
(the center of pads)
Coordinates (m)
N
Pad size (m)
X
Y
1 190x190 220.5
1640
1 190x190 1244
1900
2 190x500 985.5
619.5
3 190x190 1893.5
2399
3 190x190 2935
2403
3 190x190 3716.5
603.5
4 190x190 3716.5
254
5 190x190 3716.5
2399
Page 9 of 9
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