19-2988; Rev 3; 5/09
KIT
ATION
EVALU
BLE
AVAILA
1A, 76V, High-Efficiency MAXPower
Step-Down DC-DC Converter
General Description
Features
♦
Wide 7.5V to 76V Input Voltage Range
♦
Fixed (3.3V, 5V, 12V) and Adjustable
(1.25V to 13.2V) Versions
♦
1A Output Current
♦
Efficiency Up to 94%
♦
Internal 0.4Ω High-Side DMOS FET
♦
270µA Quiescent Current at No Load, 10µA
Shutdown Current
♦
Internal Frequency Compensation
♦
Fixed 125kHz Switching Frequency
♦
Thermal Shutdown and Short-Circuit Current
Limit
♦
8-Pin SO and PDIP Packages
MAX5035
The MAX5035 easy-to-use, high-efficiency, high-volt-
age, step-down DC-DC converter operates from an
input voltage up to 76V and consumes only 270µA qui-
escent current at no load. This pulse-width modulated
(PWM) converter operates at a fixed 125kHz switching
frequency at heavy loads, and automatically switches
to pulse-skipping mode to provide low quiescent cur-
rent and high efficiency at light loads. The MAX5035
includes internal frequency compensation simplifying
circuit implementation. The device uses an internal low-
on-resistance, high-voltage, DMOS transistor to obtain
high efficiency and reduce overall system cost. This
device includes undervoltage lockout, cycle-by-cycle
current limit, hiccup mode output short-circuit protec-
tion, and thermal shutdown.
The MAX5035 delivers up to 1A output current. The out-
put current may be limited by the maximum power dis-
sipation capability of the package. External shutdown is
included, featuring 10µA (typ) shutdown current. The
MAX5035A/B/C versions have fixed output voltages of
3.3V, 5V, and 12V, respectively, while the MAX5035D
features an adjustable output voltage from 1.25V to
13.2V.
The MAX5035 is available in space-saving 8-pin SO
and 8-pin plastic DIP packages and operates over the
automotive (-40°C to +125°C) temperature range.
Ordering Information
PART
MAX5035AUSA
MAX5035AUPA
MAX5035AASA
MAX5035BUSA
MAX5035BUPA
MAX5035BASA
TEMP RANGE
0°C to +85°C
0°C to +85°C
PIN-
PACKAGE
8 SO
8 PDIP
3.3
OUTPUT
VOLTAGE
(V)
-40°C to +125°C 8 SO
0°C to +85°C
0°C to +85°C
8 SO
8 PDIP
MAX5035AASA/V+ -40°C to +125°C 8 SO
Applications
Automotive
Consumer Electronics
Industrial
Distributed Power
-40°C to +125°C 8 SO
5.0
MAX5035BASA/V+ -40°C to +125°C 8 SO
+Denotes
lead(Pb)-free/RoHS-compliant package.
Ordering Information continued at end of data sheet.
Typical Operating Circuit
V
IN
7.5V TO 76V
68μF
V
IN
BST
0.1μF
100μH
LX
ON/OFF
ON
R2
OFF
SGND
GND
FB
VD
0.1μF
D1
50SQ100
Pin Configuration
TOP VIEW
MAX5035
R1
V
OUT
5V
68μF
BST
VD
SGND
FB
1
2
3
4
8
LX
V
IN
GND
ON/OFF
MAX5035
7
6
5
SO/PDIP
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
1A, 76V, High-Efficiency MAXPower
Step-Down DC-DC Converter
MAX5035
ABSOLUTE MAXIMUM RATINGS
(Voltages referenced to GND, unless otherwise specified.)
V
IN
.........................................................................-0.3V to +80V
SGND ....................................................................-0.3V to +0.3V
LX.................................................................-0.8V to (V
IN
+ 0.3V)
BST ...............................................................-0.3V to (V
IN
+ 10V)
BST (transient < 100ns) ................................-0.3V to (V
IN
+ 15V)
BST to LX................................................................-0.3V to +10V
BST to LX (transient < 100ns) ................................-0.3V to +15V
ON/OFF........................................................-0.3V to (V
IN
+ 0.3V)
VD...........................................................................-0.3V to +12V
FB
MAX5035A/MAX5035B/MAX5035C ...................-0.3V to +15V
MAX5035D .........................................................-0.3V to +12V
V
OUT
Short-Circuit Duration (V
IN
≤
40V)........................Indefinite
VD Short-Circuit Duration ..............................................Indefinite
Continuous Power Dissipation (T
A
= +70°C)
8-Pin PDIP (derate 9.1mW/°C above +70°C)...............727mW
8-Pin SO (derate 5.9mW/°C above +70°C)..................471mW
Operating Temperature Range
MAX5035_U_ _ ...................................................0°C to +85°C
MAX5035_A_ _ ..............................................-40°C to +125°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°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 (MAX5035_U_ _)
(V
IN
= +12V, V
ON/OFF
= +12V, I
OUT
= 0,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C. See the
Typical Application Circuit.)
PARAMETER
SYMBOL
MAX5035A
Input Voltage Range
V
IN
MAX5035B
MAX5035C
MAX5035D
Undervoltage Lockout
UVLO
MAX5035A
Output Voltage
V
OUT
MAX5035B
MAX5035C
Feedback Voltage
V
FB
V
IN
= 7.5V to 76V,
I
OUT
= 20mA to 1A
V
IN
= 7.5V to 76V,
I
OUT
= 20mA to 1A
V
IN
= 15V to 76V,
I
OUT
= 20mA to 1A
3.185
4.85
11.64
1.192
CONDITIONS
MIN
7.5
7.5
15
7.5
5.2
3.3
5.0
12
1.221
86
90
94
90
270
270
270
270
10
1.30
1.80
1
0.40
0.80
440
440
440
440
45
2.50
µA
A
µA
Ω
µA
%
3.415
5.15
12.36
1.250
V
V
TYP
MAX
76.0
76.0
76
76.0
V
V
UNITS
V
IN
= 7.5V to 76V, MAX5035D
V
IN
= 12V, I
LOAD
= 0.5A, MAX5035A
V
IN
= 12V, I
LOAD
= 0.5A, MAX5035B
Efficiency
η
V
IN
= 24V, I
LOAD
= 0.5A, MAX5035C
V
IN
= 12V, V
OUT
= 5V, I
LOAD
= 0.5A,
MAX5035D
V
FB
= 3.5V, V
IN
= 7.5V to 76V, MAX5035A
V
FB
= 5.5V, V
IN
= 7.5V to 76V, MAX5035B
V
FB
= 13V, V
IN
= 15V to 76V, MAX5035C
V
FB
= 1.3V, MAX5035D
V
ON/OFF
= 0V, V
IN
= 7.5V to 76V
(Note 1)
V
IN
= 76V, V
ON/OFF
= 0V, V
LX
= 0V
I
SWITCH
= 1A
Quiescent Supply Current
I
Q
Shutdown Current
Peak Switch Current Limit
Switch Leakage Current
Switch On-Resistance
I
SHDN
I
LIM
I
OL
R
DS(ON)
2
_______________________________________________________________________________________
1A, 76V, High-Efficiency MAXPower
Step-Down DC-DC Converter
ELECTRICAL CHARACTERISTICS (continued) (MAX5035_U_ _)
(V
IN
= +12V, V
ON/OFF
= +12V, I
OUT
= 0,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C. See the
Typical Application Circuit.)
PARAMETER
PFM Threshold
FB Input Bias Current
ON/OFF CONTROL INPUT
ON/OFF Input-Voltage Threshold
ON/OFF Input-Voltage Hysteresis
ON/OFF Input Current
OSCILLATOR
Oscillator Frequency
Maximum Duty Cycle
VOLTAGE REGULATOR
Regulator Output Voltage
Dropout Voltage
Load Regulation
Thermal Resistance
(Junction to Ambient)
THERMAL SHUTDOWN
Thermal-Shutdown Junction
Temperature
Thermal-Shutdown Hysteresis
T
SH
T
HYST
+160
20
°C
°C
ΔVD/ΔI
VD
PACKAGE THERMAL CHARACTERISTICS
θ
JA
SO package (JEDEC 51)
DIP package (JEDEC 51)
170
110
°C/W
VD
V
IN
= 8.5V to 76V, I
L
= 0
7.5V
≤
V
IN
≤
8.5V, I
L
= 1mA
0 to 5mA
6.9
7.8
2.0
150
8.8
V
V
Ω
f
OSC
D
MAX
MAX5035D
109
125
95
135
kHz
%
V
ON/OFF
V
HYST
I
ON/OFF
V
ON/OFF
= 0V to V
IN
Rising trip point
1.53
1.69
100
10
150
1.85
V
mV
nA
SYMBOL
I
PFM
I
B
MAX5035D
CONDITIONS
Minimum switch current in any cycle
MIN
55
-150
TYP
85
+0.01
MAX
130
+150
UNITS
mA
nA
MAX5035
ELECTRICAL CHARACTERISTICS (MAX5035_A_ _)
(V
IN
= +12V, V
ON/OFF
= +12V, I
OUT
= 0,
T
A
= T
J
= -40°C to +125°C,
unless otherwise noted. Typical values are at T
A
= +25°C. See
the
Typical Application Circuit.)
(Note 2)
PARAMETER
SYMBOL
MAX5035A
Input Voltage Range
V
IN
MAX5035B
MAX5035C
MAX5035D
Undervoltage Lockout
UVLO
MAX5035A
Output Voltage
V
OUT
MAX5035B
MAX5035C
Feedback Voltage
V
FB
V
IN
= 7.5V to 76V,
I
OUT
= 20mA to 1A
V
IN
= 7.5V to 76V,
I
OUT
= 20mA to 1A
V
IN
= 15V to 76V,
I
OUT
= 20mA to 1A
3.185
4.825
11.58
1.192
CONDITIONS
MIN
7.5
7.5
15
7.5
5.2
3.3
5.0
12
1.221
3.415
5.175
12.42
1.250
V
V
TYP
MAX
76.0
76.0
76
76.0
V
V
UNITS
V
IN
= 7.5V to 76V, MAX5035D
_______________________________________________________________________________________
3
1A, 76V, High-Efficiency MAXPower
Step-Down DC-DC Converter
MAX5035
ELECTRICAL CHARACTERISTICS (MAX5035_A_ _)
(V
IN
= +12V, V
ON/OFF
= +12V, I
OUT
= 0,
T
A
= T
J
= -40°C to +125°C,
unless otherwise noted. Typical values are at T
A
= +25°C. See
the
Typical Application Circuit.)
(Note 2)
PARAMETER
SYMBOL
CONDITIONS
V
IN
= 12V, I
LOAD
= 0.5A, MAX5035A
V
IN
= 12V, I
LOAD
= 0.5A, MAX5035B
Efficiency
η
V
IN
= 24V, I
LOAD
= 0.5A, MAX5035C
V
IN
= 12V, V
OUT
= 5V, I
LOAD
= 0.5A,
MAX5035D
V
FB
= 3.5V, V
IN
= 7.5V to 76V, MAX5035A
Quiescent Supply Current
I
Q
V
FB
= 5.5V, V
IN
= 7.5V to 76V, MAX5035B
V
FB
= 13V, V
IN
= 15V to 76V, MAX5035C
V
FB
= 1.3V, MAX5035D
Shutdown Current
Peak Switch Current Limit
Switch Leakage Current
Switch On-Resistance
PFM Threshold
FB Input Bias Current
ON/OFF CONTROL INPUT
ON/OFF Input-Voltage Threshold
ON/OFF Input-Voltage Hysteresis
ON/OFF Input Current
OSCILLATOR
Oscillator Frequency
Maximum Duty Cycle
VOLTAGE REGULATOR
Regulator Output Voltage
Dropout Voltage
Load Regulation
Thermal Resistance
(Junction to Ambient)
THERMAL SHUTDOWN
Thermal-Shutdown Junction
Temperature
Thermal-Shutdown Hysteresis
T
SH
T
HYST
+160
20
°C
°C
ΔVD/ΔI
VD
PACKAGE THERMAL CHARACTERISTICS
θ
JA
SO package (JEDEC 51)
DIP package (JEDEC 51)
170
110
°C/W
VD
V
IN
= 8.5V to 76V, I
L
= 0
7.5V
≤
V
IN
≤
8.5V, I
L
= 1mA
0 to 5mA
6.5
7.8
2.0
150
9.0
V
V
Ω
f
OSC
D
MAX
MAX5035D
105
125
95
137
kHz
%
V
ON/OFF
V
HYST
I
ON/OFF
V
ON/OFF
= 0V to V
IN
Rising trip point
1.50
1.69
100
10
150
1.85
V
mV
nA
I
SHDN
I
LIM
I
OL
R
DS(ON)
I
PFM
I
B
V
ON/OFF
= 0V, V
IN
= 7.5V to 76V
(Note 1)
V
IN
= 76V, V
ON/OFF
= 0V, V
LX
= 0V
I
SWITCH
= 1A
Minimum switch current in any cycle
MAX5035D
55
-150
1.30
MIN
TYP
86
90
94
90
270
270
270
270
10
1.80
1
0.40
85
+0.01
0.80
130
+150
440
440
440
440
45
2.50
µA
A
µA
Ω
mA
nA
µA
%
MAX
UNITS
Note 1:
Switch current at which current limit is activated.
Note 2:
All limits at -40°C are guaranteed by design, not production tested.
4
_______________________________________________________________________________________
1A, 76V, High-Efficiency MAXPower
Step-Down DC-DC Converter
Typical Operating Characteristics
(V
IN
= 12V, V
ON/OFF
= 12V, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at T
A
= +25°C. See the
Typical
Application Circuit,
if applicable.)
V
OUT
vs. TEMPERATURE
(MAX5035AASA, V
OUT
= 3.3V)
MAX5035 toc01
MAX5035
V
OUT
vs. TEMPERATURE
(MAX5035DASA, V
OUT
= 5V)
MAX5035 toc02
LINE REGULATION
(MAX5035AASA, V
OUT
= 3.3V)
I
OUT
= 0.1A
3.36
OUTPUT VOLTAGE (V)
I
OUT
= 1A
3.32
MAX5035 toc03
3.40
I
OUT
= 0.1A
3.36
I
OUT
= 1A
V
OUT
(V)
5.20
5.15
5.10
V
OUT
(V)
3.40
3.32
5.05
5.00
4.95
4.90
4.85
I
OUT
= 0.1A
3.28
3.28
I
OUT
= 1A
3.24
3.24
3.20
-50
-25
0
25
50
75
100
125
150
TEMPERATURE (°C)
4.80
-50
-25
0
25
50
75
100 125 150
TEMPERATURE (°C)
3.20
5
20
35
50
65
80
INPUT VOLTAGE (V)
LINE REGULATION
(MAX5035DASA, V
OUT
= 5V)
MAX5035 toc04
LOAD REGULATION
(MAX5035AASA, V
OUT
= 3.3V)
MAX5035 toc05
LOAD REGULATION
(MAX5035DASA, V
OUT
= 5V)
MAX5035 toc06
5.20
5.15
OUTPUT VOLTAGE (V)
5.10
3.40
V
IN
= 76V
3.36
V
IN
= 7.5V, 24V
V
OUT
(V)
5.10
5.05
V
IN
= 24V
V
OUT
(V)
V
IN
= 7.5V
5.00
V
IN
= 76V
5.05
5.00
4.95
4.90
4.85
4.80
5
I
OUT
= 0.1A
3.32
I
OUT
= 1A
3.28
4.95
3.24
3.20
20
35
50
65
80
0
200
400
600
800
1000
INPUT VOLTAGE (V)
I
LOAD
(mA)
4.90
0
200
400
600
800
1000
I
LOAD
(mA)
_______________________________________________________________________________________
5
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