MAX727ECK+ [MAXIM]
Switching Regulator, 3.2A, 110kHz Switching Freq-Max, BIPolar, PZFM5, LEAD FREE, TO-220, 5 PIN;
| 型号： | MAX727ECK+ |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Switching Regulator, 3.2A, 110kHz Switching Freq-Max, BIPolar, PZFM5, LEAD FREE, TO-220, 5 PIN 稳压器 开关 |
| 文件： | 总4页 (文件大小：41K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-0149; Rev 2; 9/95
5 V/3 .3 V/3 V 2 A S t e p -Do w n , P WM,
S w it c h -Mo d e DC-DC Re g u la t o rs
8/MAX729
_______________Ge n e ra l De s c rip t io n
___________________________Fe a t u re s
♦ Input Range: Up to 40V
The MAX727/MAX728/MAX729 are monolithic, bipolar,
pulse-width modulation (PWM), switch-mode, step-down
DC-DC regulators. Each is rated at 2A. Very few external
components are needed for standard operation because
the power switch, oscillator, feedback, and control circuitry
are all on-chip. Employing a classic buck topology, these
regulators perform high-current step-down functions.
♦ 2A On-Chip Power Switch
♦ Fixed Outputs: 5V (MAX727)
3.3V (MAX728)
3V (MAX729)
♦ 100kHz Switching Frequency
♦ Excellent Dynamic Characteristics
♦ Few External Components
♦ 8.5mA Quiescent Current
♦ TO-220 Package
These regulators have excellent dynamic and transient
response characteristics, while featuring cycle-by-cycle cur-
rent limiting to protect against overcurrent faults and short-
circuit output faults. They also have a wide 8V to 40V input
range.
Each regulator is available in a 5-pin TO-220 package.
These devices have a preset 100kHz oscillator frequency
and a preset current limit of 2.6A. See the MAX724/
MAX726 data sheet for more applications information.
______________Ord e rin g In fo rm a t io n
PART
TEMP. RANGE
0°C to +70°C
PIN-PACKAGE
5 TO-220
MAX727CCK
MAX727ECK
MAX728CCK
MAX728ECK
MAX729CCK
MAX729ECK
_______________________Ap p lic a t io n s
-40°C to +85°C
0°C to +70°C
5 TO-220
Distributed Power from High-Voltage Buses
High-Current, High-Voltage Step-Down Applications
Multiple-Output Buck Converter
5 TO-220
-40°C to +85°C
0°C to +70°C
5 TO-220
5 TO-220
-40°C to +85°C
5 TO-220
__________________P in Co n fig u ra t io n
__________Typ ic a l Op e ra t in g Circ u it
FRONT VIEW
INPUT
8V TO 40V
OUTPUT
5V AT 2A
100µH
V
IN
V
SW
220µF
V
IN
MBR745
5
4
MAX727
MAX727
MAX728
MAX729
V
SW
V
C
SENSE
GND
3
2
470µF
V
C
2.7k
1
SENSE
GND
0.01µF
5-PIN TO-220
CASE IS CONNECTED TO GROUND. STANDARD PACKAGE HAS STAGGERED LEADS.
CONTACT FACTORY FOR STRAIGHT LEADS.
STEP-DOWN CONVERTER
________________________________________________________________ Maxim Integrated Products
1
Ca ll t o ll fre e 1 -8 0 0 -9 9 8 -8 8 0 0 fo r fre e s a m p le s o r lit e ra t u re .
5 V/3 .3 V/3 V 2 A S t e p -Do w n , P WM,
S w it c h -Mo d e DC-DC Re g u la t o rs
ABSOLUTE MAXIMUM RATINGS
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45V
Switch Voltage with Respect to Input Voltage . . . . . . . . . . . . . . . . 50V
Switch Voltage with Respect to GND Pin (VSW negative)
(Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35V
SENSE Pin Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V, +10V
Operating Temperature Ranges
Junction Temperature Ranges:
MAX72_CCK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +125°C
MAX72_ECK. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +125°C
Storage Temperature Range . . . . . . . . . . . . . . . . . . . -65°C to +160°C
Lead Temperature (soldering, 10sec). . . . . . . . . . . . . . . . . . . . +300°C
MAX72_CCK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C
MAX72_ECK. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VIN = 25V, Tj = TMIN to TMAX, unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Input Supply Voltage Range
8.0
40.0
V
I
= 0.5A
= 2A
1.2
1.7
SW
Switch-On Voltage (Note 2)
V
I
SW
V
= 25V, V = 0V
T = +25°C
150
250
IN
SW
j
Switch-Off Leakage
µA
V
IN
= 40V, V = 0V
T = +25°C
j
SW
8/MAX729
Supply Current (Note 3)
V
≤ 40V, V
= 5.5V
8.5
7.3
11
mA
IN
SENSE
Normal Mode
Start-Up Mode (Note 4)
8.0
Minimum Supply Voltage
V
T ≥ 0°C
3.5
3.5
2.6
4.8
5.0
3.2
j
T < 0°C
j
Switch-Current Limit (Note 5)
Maximum Duty Cycle
2.0
85
A
90
%
T = +25°C
90
85
100
110
120
j
Switching Frequency
T ≤ +125°C
j
kHz
V
OUT
= V
= 0V (Note 5) T = +25°C
20
SENSE
j
Switching Frequency Line Regulation 8V ≤ V ≤ 40V
0.03
0.10
%/V
V/V
IN
Error-Amplifier Voltage Gain
Error-Amplifier Transconductance
Error-Amplifier Source Current
Error-Amplifier Sink Current
1V ≤ V ≤ 4V
T = +25°C
2000
5000
140
C
j
T = +25°C
j
3000
100
0.6
9000
225
1.7
µmho
µA
V
SENSE
= V
- 10%
T = +25°C
j
OUT
V
SENSE
= V
+ 10%
T = +25°C
j
1.0
mA
OUT
2
_______________________________________________________________________________________
5 V/3 .3 V/3 V 2 A S t e p -Do w n , P WM,
S w it c h -Mo d e DC-DC Re g u la t o rs
8/MAX729
ELECTRICAL CHARACTERISTICS (continued)
(VIN = 25V, Tj = TMIN to TMAX, unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
MAX727
MAX728
MAX729
MAX727
MAX728
MAX729
4.85
3.20
2.90
3.0
5.00
3.30
3.00
5.0
5.15
3.40
3.10
8.0
SENSE Voltage
V
= 2V
V
C
SENSE Pin Divider Resistance
T = +25°C
j
2.5
4.2
7.0
kΩ
2.2
3.8
6.5
V
(nominal) = 5V (MAX727),
OUT
T = +25°C
±0.5
±1.0
±2.0
j
3.3V (MAX728), or 3V (MAX729);
all conditions of input voltage,
output voltage, and load
current
Output Voltage Tolerance
%
T = T
j
to
MIN
±3.0
T
MAX
Output Voltage Line Regulation
8V ≤ V ≤ 40V
0.005
1.5
0.020
%/V
V
IN
V
Voltage
0% duty cycle
T = +25°C
j
C
V
C
Voltage Temperature Coefficient 0% duty cycle
T = T
to T
MAX
-4
mV/°C
j
MIN
Thermal Resistance Junction to Case
(Note 6)
4.0
°C/W
Note 1: Do not exceed switch-to-input voltage limitation.
Note 2: For switch currents between 1A and 2A, maximum switch-on voltage can be calculated via linear interpolation.
Note 3: By setting the SENSE pin to 5.5V, the VC pin is forced to its low clamp level and the switch duty cycle is forced to zero,
approximating the zero load condition.
Note 4: For proper regulation, total voltage from VIN to GND must be ≥ 8V after start-up.
Note 5: To avoid extremely short switch-on times, the switch frequency is internally scaled down when VSENSE is less than 2.6V
(MAX727), 2.0V (MAX728), or 1.8V (MAX729). Switch current limit is tested with VSENSE adjusted to give a 1µs minimum
switch-on time.
Note 6: Guaranteed, not production tested.
______________________________________________________________P in De s c rip t io n
PIN
NAME
FUNCTION
SENSE Input is the internal error amplifier's input, and should be directly connected to V
.
OUT
1
SENSE
SENSE also aids current limiting by reducing oscillator frequency when V
is low.
OUT
Error-Amplifier Output. A series RC network connected to this pin compensates the
MAX727/MAX728/MAX729. Output swing is limited to about 5.8V in the positive direction and
-0.7V in the negative direction. VC can also synchronize the MAX727/MAX728/MAX729 to an
external TTL clock in the 115kHz to 170kHz range. See MAX724/MAX726 data sheet.
VC
2
Ground requires a short, low-noise connection to ensure good load regulation. The internal refer-
ence is referred to GND, so errors at this pin are multiplied by the error amplifier.
3
4
5
GND
VSW
Internal Power Switch Output. The Switch output can swing 35V below ground and is rated for 2A.
VIN supplies power to the internal circuitry and also connects to the collector of the internal power
V
IN
switch. VIN must be bypassed with a low-ESR capacitor, typically 200µF or 220µF.
_______________________________________________________________________________________
3
5 V/3 .3 V/3 V 2 A S t e p -Do w n , P WM,
S w it c h -Mo d e DC-DC Re g u la t o rs
________________________________________________________P a c k a g e In fo rm a t io n
INCHES
MILLIMETERS
DIM
A
MIN
MAX
0.190
0.040
0.022
0.650
0.420
MIN
3.56
0.38
0.41
14.23
9.66
MAX
4.82
E
F
A
B
0.140
0.015
φP
1.01
Q
C1 0.014
0.50
H1
D
E
e
0.560
0.380
16.51
10.66
0.067 BSC
1.70 BSC
D
F
0.045
0.055
0.270
0.115
0.185
0.335
0.200
0.340
0.720
0.161
0.120
1.14
5.85
2.04
4.32
8.31
4.32
6.60
17.78
3.54
2.54
1.39
6.85
2.92
4.70
8.51
5.08
8.64
18.29
4.08
H1 0.230
L2
J1
J2
J3
L
0.080
0.170
0.327
0.170
0.260
0.700
J1
L1
L2
φP 0.139
Q
0.100
3.04
21-005-
L
L1
J2
5-PIN TO-220
(STAGGERED LEAD)
PACKAGE
C1
B
e
8/MAX729
J3
INCHES
MILLIMETERS
DIM
MIN
MAX
0.190
0.040
0.022
0.650
0.420
MIN
3.56
0.38
0.41
14.23
9.66
MAX
4.82
A
E
A
B
0.140
0.015
F
1.01
φP
Q
C1 0.014
0.50
D
E
e
0.560
0.380
16.51
10.66
H1
0.067 BSC
1.70 BSC
F
0.045
0.055
0.270
0.115
0.580
0.161
0.120
1.14
5.85
2.04
12.70
3.54
2.54
1.39
6.85
D
H1 0.230
J1
L
0.080
0.500
2.92
14.73
4.08
φP 0.139
0.100
Q
3.04
21-4737-
J1
L
5-PIN TO-220
(STRAIGHT LEAD)
PACKAGE
B
C1
e
CONTACT FACTORY FOR AVAILABILITY
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
4
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© 1995 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
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