EVALUATION KIT AVAILABLE
AVAILAB
LE
MAX5035
1A, 76V, High-Efficiency MAXPower
Step-Down DC-DC Converter
General Description
Features
o
Wide 7.5V to 76V Input Voltage Range
o
Fixed (3.3V, 5V, 12V) and Adjustable
(1.25V to 13.2V) Versions
o
1A Output Current
o
Efficiency Up to 94%
o
Internal 0.4Ω High-Side DMOS FET
o
270µA Quiescent Current at No Load, 10µA
Shutdown Current
o
Internal Frequency Compensation
o
Fixed 125kHz Switching Frequency
o
Thermal Shutdown and Short-Circuit Current
Limit
o
8-Pin SO and PDIP Packages
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/E
versions have 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
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
Automotive
Industrial
Applications
Functional Diagrams
Consumer Electronics
Distributed Power
-40°C to +125°C 8 SO
5.0
MAX5035BASA/V+ -40°C to +125°C 8 SO
/V denotes an automotive qualified part.
+Denotes
a 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
Pin Configurations appear at end of data sheet.
Functional Diagrams continued at end of data sheet.
UCSP is a trademark of Maxim Integrated Products, Inc.
SO/PDIP
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-2988; Rev 5; 5/11
MAX5035
1A, 76V, High-Efficiency MAXPower
Step-Down DC-DC Converter
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 +80V
VD...........................................................................-0.3V to +12V
FB
MAX5035A/MAX5035B/MAX5035C ...................-0.3V to +15V
MAX5035D/E ......................................................-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
Soldering Temperature (reflow)
Lead(Pb)-free...............................................................+260°C
Containing lead(Pb) .....................................................+240°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/E
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
1.185
CONDITIONS
MIN
7.5
7.5
15
7.5
5.2
3.3
5.0
12
1.221
1.221
86
90
94
90
270
270
270
270
340
10
1.30
1.9
440
440
440
440
460
45
2.50
µA
A
µA
%
3.415
5.15
12.36
1.250
1.250
V
V
TYP
MAX
76.0
76.0
76
76.0
V
V
UNITS
V
IN
= 7.5V to 76V, MAX5035D/E
V
IN
= 7.5V to 76V, MAX5035E
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/E
V
FB
= 3.5V, V
IN
= 7.5V to 76V, MAX5035A
V
FB
= 5.5V, V
IN
= 7.5V to 76V, MAX5035B
Quiescent Supply Current
I
Q
V
FB
= 13V, V
IN
= 15V to 76V, MAX5035C
V
FB
= 1.3V, MAX5035D
V
FB
= 1.3V, MAX5035E
Shutdown Current
Peak Switch Current Limit
2
I
SHDN
I
LIM
V
ON/OFF
= 0V, V
IN
= 7.5V to 76V
(Note 1)
Maxim Integrated
MAX5035
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
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
ON/OFF Operating Voltage
Range
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
∆VD/∆I
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/E
109
125
95
135
kHz
%
V
ON/OFF
V
HYST
I
ON/OFF
V
ON/OFF
V
ON/OFF
= 0V to V
IN
Rising trip point for MAX5035A/B/C/D
Rising trip point for MAX5035E
1.53
1.40
1.69
1.65
100
10
150
76
1.85
1.90
V
mV
nA
V
SYMBOL
I
OL
R
DS(ON)
I
PFM
I
B
I
SWITCH
= 1A
Minimum switch current in any cycle
MAX5035D/E
55
-150
CONDITIONS
V
IN
= 76V, V
ON/OFF
= 0V, V
LX
= 0V
MIN
TYP
0.01
0.40
85
+0.01
MAX
1
0.80
130
+150
UNITS
µA
Ω
mA
nA
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/E
Undervoltage Lockout
UVLO
MAX5035A
Output Voltage
V
OUT
MAX5035B
MAX5035C
Maxim Integrated
CONDITIONS
MIN
7.5
7.5
15
7.5
TYP
MAX
76.0
76.0
76
76.0
UNITS
V
5.2
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
3.3
5.0
12
3.415
5.175
12.42
V
V
3
MAX5035
1A, 76V, High-Efficiency MAXPower
Step-Down DC-DC Converter
ELECTRICAL CHARACTERISTICS (MAX5035_A_ _) (continued)
(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
Feedback Voltage
SYMBOL
V
FB
CONDITIONS
V
IN
= 7.5V to 76V, MAX5035D
V
IN
= 7.5V to 76V, MAX5035E
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/E
V
FB
= 3.5V, V
IN
= 7.5V to 76V, MAX5035A
V
FB
= 5.5V, V
IN
= 7.5V to 76V, MAX5035B
Quiescent Supply Current
I
Q
V
FB
= 13V, V
IN
= 15V to 76V, MAX5035C
V
FB
= 1.3V, MAX5035D
V
FB
= 1.3V, MAX5035E
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
ON/OFF Operating Voltage
Range
OSCILLATOR
Oscillator Frequency
Maximum Duty Cycle
VOLTAGE REGULATOR
Regulator Output Voltage
Dropout Voltage
Load Regulation
∆VD/∆I
VD
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/E
105
125
95
137
kHz
%
V
ON/OFF
V
HYST
I
ON/OFF
V
ON/OFF
V
ON/OFF
= 0V to V
IN
Rising trip point for MAX5035A/B/C/D
Rising trip point for MAX5035E
1.50
1.40
1.69
1.65
100
10
150
76
1.85
1.90
V
mV
nA
V
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
V
IN
= 76V, V
ON/OFF
= 0V, V
LX
= 0V,
MAX5035E
I
SWITCH
= 1A
Minimum switch current in any cycle
MAX5035D/E
55
-150
0.40
85
+0.01
1.30
MIN
1.192
1.185
TYP
1.221
1.221
86
90
94
90
270
270
270
270
340
10
1.9
1
5
0.80
130
+150
µA
Ω
mA
nA
440
440
440
440
460
45
2.50
µA
A
µA
%
MAX
1.250
1.250
UNITS
V
4
Maxim Integrated
MAX5035
1A, 76V, High-Efficiency MAXPower
Step-Down DC-DC Converter
ELECTRICAL CHARACTERISTICS (MAX5035_A_ _) (continued)
(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
Thermal Resistance
(Junction to Ambient)
THERMAL SHUTDOWN
Thermal-Shutdown Junction
Temperature
Thermal-Shutdown Hysteresis
T
SH
T
HYST
+160
20
°C
°C
SYMBOL
CONDITIONS
SO package (JEDEC 51)
DIP package (JEDEC 51)
MIN
TYP
170
110
MAX
UNITS
PACKAGE THERMAL CHARACTERISTICS
θ
JA
°C/W
Note 1:
Switch current at which current limit is activated.
Note 2:
All limits at -40°C are guaranteed by design, not production tested.
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
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
3.24
4.95
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)
Maxim Integrated
5
