LM2576 Series
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. Ex
ternal
shutdown is included, featuring 50µA (typical) standby current. The output switch includes cycle-by-cycle current limiting, as well
thermal shutdown for full protection under fault conditions.
Note: The MIK2576HV is not produced
y
et.
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)
T
pical application
Figure 1.(Fixed Output Voltage Versions)
7V
-
40V
(60V for
HV)
UNREGULATED
+
V
IN
1
MIK2576/
MIK2576HV-
5.0
FEEDBACK
4
OUTPUT
2
+5V
REGULATED
DC INPUT
+
3
GND
C
IN
5
ON/OFF
10
0
H
D1
1N5822
+C
OUT
1
0
0
0
F
OUT
P
UT
3A
LOAD
1
BE
IJI
N
G
ES
T
E
K
ELE
CTR
O
N
I
C
S C
O
.,
L
T
D
LM2576 Series
Block Diagram
UNREGULATED
DCINPUT
+
V
IN
1
4
I
N
T
E
R
N
AL
REGULATOR ON/OFF 5
ON
/
OF
F
C
IN
FEED-
BACK
R2
FIXED GAIN
ERRORAMP
D
R
IVER
3
A
M
P
R1
1.0k
1.2
3
V
+
-
CO
M
P
A
R
A
T
O
R
+
-
S
W
I
T
C
H
2
3
OU
TP
UT
D1
L1
+
V
OUT
C
OUT
L
O
A
B
A
N
D
-
G
AP
5
2
k
HZ
T
H
E
R
M
A
L
C
U
R
R
E
N
T
D
REFERENCE
O
S
C
IL
L
A
T
O
R
RESET
S
H
U
T
D
O
W
N
L
I
M
I
T
G
N
D
3.3V, R2 =1.7K
5V, R2 = 3.1K
12V, R2 = 8.84K
15V, R2 =11.3K
For ADJ, Version
R1 = Open, R2 =0Ω
Ordering information
Temperature
Range
Output
Voltage,
V
Package
T
y
pe
-
4
0
°
C
≤
T
A
≤125°C
3.3
5.0
12
15
A
D
J
MIK2576HVS-3.3 MIK2576HVS-5.0 MIK2576HVS-12 MIK2576HVS-15 MIK2576HVS-ADJ
MIK2576S-3.3 MIK2576S-5.0 MIK2576S-12 MIK2576S-15 MIK2576S-ADJ
MIK2576HVT-3.3 MIK2576HVT-5.0 MIK2576HVT-12 MIK2576HVT-15 MIK2576HVT-
ADJ
MIK2576T
-
3.3
MIK2576T
-
5.0
MIK2576T
-
12
MIK2576T
-
15
MIK2576T
-
ADJ
TO
-
263
TO
-
220
2
BE
IJI
N
G
ES
T
E
K
ELE
CTR
O
N
I
C
S C
O
.,
L
T
D
LM2576 Series
Absolute Maximum Ratings
(Note 1)
Paramete
r
Maximu
m
Units
Maximum Suppl
y
Voltage
MIK2576
MIK2576HV
45
63
V
ON/OFF Pin Input Voltage -0.3V ≤V≤+V
IN
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 kΩ) 2 kV
Lead Temperature (Soldering, 10 Seconds) 260 °C
Operating Ratings
Temperature Range
MIK2576/ MIK2576HV
Suppl
y
Voltage
Parameter
Value
Units
-
4
0
≤
T
J
≤
+125
°C
MIK2576
MIK2576HV
40
60
V
Electrical Characteristics MIK2576
-
3.3, MIK2576HV
-
3.3
Specifications
w
ith standard t
y
pe face are for T
J
= 25
°
C, and those
w
ith
boldface
t
y
p
e
appl
y
over full Operating Temperature Range.
S
y
mbo
l
Paramete
r
Conditions
SYSTEM PARAMETERS
(Note 3)
Test Circuit
Figure 2
V
OUT
Output Voltage V
IN
=12V, I
LOAD
=0.5A
Circuit of
Figure 2
MIK2576
-
3.3
MIK2576HV-3.3
Typ Limit
(Note 2)
3.3 3.234
3.366
Units
(Limits)
V
V(Min)
V(Max)
V
OUT
Output Voltage
MIK2576
V
OUT
Output Voltage
MIK2576HV
6V ≤V
IN
≤40V, 0.5A ≤I
LOAD
≤
3A Circuit of Figure 2
6V ≤V
IN
≤60V, 0.5A ≤I
LOAD
≤
3A Circuit of
Figure 2
3.3
3.3
3.168/
3.135
3.432/
3.465
3.168/
3.135
3.450/
3.482
V
V(Min)
V(Max)
V
V(Min)
V(Ma
x
)
η
Efficiency
V
I
N
=12V, I
L
O
A
D
=3A
75
%
Electrical Characteristics MIK2576
-
5.0, MIK2576HV
-
5.0
Specifications
w
ith standard t
y
pe face are for T
J
= 25
°
C, and those
w
ith
boldface
t
y
p
e
appl
y
over full Operating Temperature Range.
S
y
mbo
l
Paramete
r
Conditions
SYSTEM PARAMETERS
(Note 3)
Test Circuit
Figure 2
V
OUT
Output Voltage V
IN
=12V, I
LOAD
=0.5A
Circuit of
Figure 2
MIK2576
-
5.0
MIK2576HV-5.0
Typ Limit
(Note 2)
5.0 4.900
5.100
Units
(Limits)
V
V(Min)
V(Max)
V
OUT
Output Voltage
MIK2576
V
OUT
Output Voltage
MIK2576HV
0.5A
≤
I
LOAD
≤
3A,
8V ≤V
IN
≤40V
Circuit of Figure 2
0.5A ≤I
LOAD
≤3A,
8V ≤V
IN
≤60V
Circuit of
Figure 2
5.0
5.0
4.800/
4.750
5.200/
5.250
4.800/
4.750
5.225/
5.275
V
V(Min)
V(Max)
V
V(Min)
V(Ma
x
)
η
Efficiency
V
I
N
=12V, I
L
O
A
D
=3A
77
%
3
BE
IJI
N
G
ES
T
E
K
ELE
CTR
O
N
I
C
S C
O
.,
L
T
D
LM2576 Series
Electrical Characteristics MIK2576
-
12, MIK2576HV
-
12
Specifications
w
ith standard t
y
pe face are for T
J
= 25
°
C, and those
w
ith
boldface
t
y
p
e
appl
y
over full Operating Temperature Range.
S
y
mbo
l
Paramete
r
Conditions
SYSTEM PARAMETERS
(Note 3)
Test Circuit
Figure 2
V
OUT
Output Voltage V
IN
=25V, I
LOAD
=0.5A
Circuit of
Figure 2
MIK2576
-
12
MIK2576HV-12
Typ Limit
(Note 2)
12 11.76
12.24
Units
(Limits)
V
V(Min)
V(Max)
V
OUT
Output Voltage
MIK2576
V
OUT
Output Voltage
MIK2576HV
0.5A
≤
I
LOAD
≤
3A,
15V ≤V
IN
≤40V
Circuit of Figure 2
0.5A ≤I
LOAD
≤3A,
15V ≤V
IN
≤60V
Circuit of
Figure 2
12
12
11.52/
11.40
12.48/
12.60
11.52/
11.40
12.54/
12.66
V
V(Min)
V(Max)
V
V(Min)
V(Ma
x
)
η
Efficiency
V
I
N
=15V, I
L
O
A
D
=3A
88
%
Electrical Characteristics MIK2576
-
15, MIK2576HV
-
15
Specifications
w
ith standard t
y
pe face are for T
J
= 25
°
C, and those
w
ith
boldface
t
y
p
e
appl
y
over full Operating Temperature Range.
S
y
mbo
l
Paramete
r
Conditions
SYSTEM PARAMETERS
(Note 3)
Test Circuit
Figure 2
V
OUT
Output Voltage V
IN
=25, I
LOAD
=0.5A
Circuit of
Figure 2
MIK2576
-
15
MIK2576HV-15
Typ Limit
(Note 2)
15 14.70
15.30
Units
(Limits)
V
V(Min)
V(Max)
V
OUT
Output Voltage
MIK2576
V
OUT
Output Voltage
MIK2576HV
0.5A
≤
I
LOAD
≤
3A,
18≤V
IN
≤40V
Circuit of Figure 2
0.5A ≤I
LOAD
≤3A,
18 ≤V
IN
≤60V
Circuit of
Figure 2
15
15
14.40/
14.25
15.60/
15.75
14.40/
14.25
15.68/
15.83
V
V(Min)
V(Max)
V
V(Min)
V(Ma
x
)
η
Efficiency
V
I
N
=18V, I
L
O
A
D
=3A
88
%
Electrical Characteristics MIK2576
-
ADJ, MIK2576HV
-
ADJ
Specifications
w
ith standard t
y
pe face are for T
J
= 25
°
C, and those
w
ith
boldface
t
y
p
e
appl
y
over full Operating Temperature Range.
S
y
mbo
l
Paramete
r
Conditions
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
MIK2576
-
A
D
J
MIK2576HV-ADJ
Typ Limit
(Note 2)
1.230 1.217
1.243
Units
(Limits)
V
V(Min)
V(Max)
V
OUT
Feedback Voltage
MIK2576
V
OUT
Feedback Voltage
MIK2576HV
0.5A ≤I
LOAD
≤3A , 8V ≤V
IN
≤
40V V
OUT
=5V
Circuit of Figure 2
0.5A ≤I
LOAD
≤3A, 8V ≤V
IN
≤
60V, V
OUT
=5V
Circuit of Figure 2
1.230
1.230
1.193/1
.180
1.267/1
.280
1.193/1
.180
1.273/1
.286
V
V(Min)
V(Max)
V
V(Min)
V(Ma
x
)
η
Efficiency
V
I
N
=12V, I
L
O
A
D
=3A, V
OUT
=5V
77
%
4
BE
IJI
N
G
ES
T
E
K
ELE
CTR
O
N
I
C
S C
O
.,
L
T
D
LM2576 Series
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.
S
y
mbo
l
Paramete
r
Conditions
DEVICE P
A
R
A
METERS
MIK2576
-
XX
MIK2576HV-XX
T
y
p
Limi
t
(Note
2)
Units
(Limits)
I
b
Feedback Bias Current
V
OUT
=5V (Adjustable Version Onl
y
)
50
100/
500
nA
f
O
O
scillator Frequency
(Note 8)
52
V
SAT
Saturation Voltage I
OUT
=3A (Note 4) 1.4
DC Max Duty Cycle (ON) (Note 5) 98
I
CL
Current Limit (Notes 4, 8) 5.8
I
L
Output Leakage Current
(Notes 6, 7):
Output = 0V
47/
42
58/
63
1.8/
2.0
93
4.2/
3.5
6.9/
7.5
2
kHz
kHz(Min)
kHz(Max)
V
V(Max)
%
%(Min)
A
A(Min)
A(Max)
mA(Max)
Output = -
1V
Output =
-
1V
7.5
30
mA
mA(Max)
I
Q
Quiescent Current
(Note 6)
5
10
mA
mA(Max)
I
STBY
Standb
y
Quiescent Current
___
ON/OFF
P
i
n
=
5V
(OFF)
50
200
µ
A
µ
A(Ma
x
)
___
ON/OFF
CONTROL
V
IH
__
ON/OFF
P
i
n
V
OUT
= 0V
1.4
2.2
/
2.4
V(Min)
V
IL
Logic Input Level
V
OUT
= Nominal Output Voltage 1.2 1.0/
0.8
V(Max)
I
IH
I
IL
__
ON/OFF Pin Input
Current
__
ON/OFF Pin = 5V (OFF)
__
ON/OFF
Pin
=
0V
(ON)
12
0
30
10
µ
A
µA(Max)
µA
µ
A(Ma
x
)
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 sy
stem
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 po
w
er dissipation of the IC b
y
lo
w
ering the minimum dut
y
c
y
cle from 5% do
w
n to approximatel
y
2%.
5
BE
IJI
N
G
ES
T
E
K
ELE
CTR
O
N
I
C
S C
O
.,
L
T
D
LM2576 Series
T
pical Performance Characteristics
(Circuit of Figure 2)
N
or
m
a
l
i
z
e
d
Ou
t
pu
t
V
o
l
t
a
g
e
L
i
n
e
R
e
g
u
l
a
t
i
on
D
r
opou
t
V
o
l
t
a
ge
V
IN
=
20V
I
LOA D
= 500m
A
Normalized a
t
T
J
=25°C
I
LOA D
=
50
0
m
A
T
J
=
25°C
I
L OA D
=
3
A
L
1
=
150
H
3
.
3
V
, 5
V
&
A
D
J
1
2V
& 15V
I
LOA D
=
20
0
m
A
I
L OA D
=
1
A
R
IND
=
0.1
Ω
J
UNCTIO
N
T
E
M
P
E
R
A
T
U
RE
(
°
C
)
IN
P
U
T
V
O
L
T
AG
E
(
V
)
J
UNCTIO
N
T
E
M
P
E
R
A
T
U
RE
(
°
C)
St
a
n
d
by
Qu
i
e
s
c
e
n
t
C
ur
r
e
n
t
Qu
i
e
s
c
e
n
t
C
ur
r
e
n
t
C
u
r
r
e
n
t
Li
m
it
V
IN
=
25V
V
IN
= 40V V
OUT
= 5V
Measure
d at
G
r
ound P
i
n
V
ON/OFF
=
5V
T
J
=2
5°C
V
IN
=12
V
I
LOAD
= 200mA
I
LOAD
=
3A
JU
N
C
T
I
O
N
T
EMP
E
R
A
T
URE
(
°
C)
I
N
P
UT
VO
L
T
A
GE
(V)
JU
N
C
T
IO
N
T
EMP
E
R
A
T
URE
(
°
C)
S
w
i
t
c
h
S
a
t
u
r
a
t
i
on
V
o
l
t
a
g
e
E
f
f
i
c
i
e
n
c
y
Osc
i
l
a
t
o
r
F
r
e
qu
e
n
cy
r
m
al
iz
ed
a
t 25
°
C
-
55
°
C
I
LOA D
=
3
A
1
5
V
O
U
T
T
J
=
25°
C
I
L OA D
=
20
0
m
A
V
IN
=
40
V
2
5
°C
1
5
0
°
C
5V
I
LOA D
=
3
A
I
L OA D
=
20
0
m
A
V
IN
=
12
V
S
WI
T
C
H
C
URR
E
N
T
(
A
)
I
N
P
U
T
V
O
L
T
A
G
E
(V
)
J
UN
C
T
I
O
N
T
E
M
P
E
R
A
T
U
R
E
(
°C)
M
i
ni
m
u
m
Op
era
t
in
g
V
o
l
t
a
g
e
Quiescent Current
vs Duty Cycle
F
ee
db
ack
V
ol
t
a
g
e
vs Duty Cycle
A
dj
u
st
a
b
l
e
V
e
r
si
o
n
O
n
l
y
A
d
j
u
st
a
b
l
e
V
e
r
s
i
on
On
l
y
V
IN
=
7V
A
d
j
u
st
a
b
l
e
V
e
r
s
i
o
n
O
n
l
y
I
LOAD
= 500mA
V
IN
=
4
0
V
V
OUT
≈
1.23V
I
LOAD
= 500mA
I
LOAD
=
50
0
m
A
V
IN
=
40V
V
IN
=
7V
J
U
N
C
T
I
ON
TE
MPE
R
A
TU
R
E
(°C)
D
U
TY
C
Y
C
L
E
(
%
)
D
U
TY
C
Y
C
L
E
(
%
)
6
BE
IJI
N
G
ES
T
E
K
ELE
CTR
O
N
I
C
S C
O
.,
L
T
D
LM2576 Series
M
a
x
i
m
u
m
P
o
w
e
r
D
i
ss
ip
a
t
i
o
n
(
TO
-
2
6
3)
F
e
edb
a
c
k
P
i
n
C
u
rr
e
nt
Ad
j
us
t
able
V
ers
i
on
O
nly
θ
JA
= 32°C/W
θ
JA
= 37°C/W
θ
JA
= 50°C/W
θ
JA
= 73°C/W
A
M
B
I
T
T
E
M
R
A
T
U
R
E
(
°C
)
J
U
N
C
T
I
O
N
T
E
M
R
A
TU
R
E
(
°
C
)
Switching
Wa
v
eforms
Load
Transient
Response
A
B
Output
Voltage
Change
C
L
o
ad
C
u
r
r
e
n
t
D
5
s
/
d
i
v
1
00
s
/
d
i
v
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
µ
s/div
7
BE
IJI
N
G
ES
T
E
K
ELE
CTR
O
N
I
C
S C
O
.,
L
T
D
LM2576 Series
Test Circuit and La
out 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)
UNR
EGUL
A
TED
+
+
V
IN
1
MIK2576HV-
FIXED OUTPUT
O
N
/
O
F
F
F
EE
D
B
ACK
4
OUTPUT
2
L
1
100
H
D
1
V
OUT
L
O
V
IN
D
C
I
NPUT
GN
100
F
D
3
5
+
MBR360
C
OUT
100
0
F
A
D
C
IN
— 100µF, 75V, Aluminum Electrolytic
C
OUT
— 1000µF, 25V, Aluminum Electrolytic
D1 — Schottky, MBR360
L
1
— 100µH, Pulse Eng. PE-92108
R
1
— 2k, 0.1%
R
2
—
6.12k, 0.1%
Adjustable Output Voltage Version
(Figure 2b)
7
V
-
6
0V
+
V
IN
1
1
0
0
F
MIK2576HV-
AD
J
F
EE
D
BA
C
K
4
OUTPUT
2
L1
1
0
0
H
V
OUT
5.00V
L
U
N
R
E
G
U
L
A
T
E
D
D
C
I
N
P
UT
+
C
IN
G
N
D
3
O
N/
O
F
F
5
+
C
O
U
T
R2
O
A
M
B
R
3
6
0
1
0
0
0
F
R1
D
V
OUT
=
V
REF
1
(
+
R
2
)
R
R
R
(
V
OUT
)
1
2
1
V
REF
−
where
V
RE
F
=
1.23V,
R1
between
1k
and
5k
A
d
dr
e
ss
:
6A06--6A07
Rm 6A07,Changyin Office Building ,No.88,Yong Ding Road,Hai Dian District ,Beijing
Postalcode:100039
Tel: 86-010-58895780 / 81 / 82 / 83 / 84 Fax : 010-58895793
Http://www.estek.com.cn
Email:sales@estek.com.cn
R
E
V
N
o
:
01
-
0
6
08
13
8
BE
IJI
N
G
ES
T
E
K
ELE
CTR
O
N
I
C
S C
O
.,
L
T
D