Maxim MAX5035BUSA, MAX5035BUPA, MAX5035AUSA, MAX5035AUPA, MAX5035DUPA Datasheet

General Description

The MAX5035 easy-to-use, high-efficiency, high-volt­age, step-down DC-DC converter operates from an
input voltage up to 76V and consumes only 350µA qui­escent 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 cur­rent and high efficiency at light loads. The MAX5035
includes internal frequency compensation simplifying
circuit implementation. The device uses an internal low­on-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 protec­tion, and thermal shutdown.

The MAX5035 delivers up to 1A output current. 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
industrial (0°C to +85°C) temperature range.

Applications

Consumer Electronics

Industrial

Distributed Power

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

♦ 350µA 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

1A, 76V, High-Efficiency MAXPower

Step-Down DC-DC Converter

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-2988; Rev 0; 9/03

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Pin Configuration

MAX5035

GND

BST

LX

V

IN

SGND

FB

D1
50SQ100

VD

100µH

V

OUT

5V

V

IN

7.5V TO 76V

68µF

0.1µF

0.1µF

68µF

ON

OFF

R1

R2

ON/OFF

Typical Operating Circuit

PART TEMP RANGE

MAX5035AUSA 0°C to +85°C 8 SO
MAX5035AUPA 0°C to +85°C 8 PDIP
MAX5035BUSA 0°C to +85°C 8 SO
MAX5035BUPA 0°C to +85°C 8 PDIP
MAX5035CUSA 0°C to +85°C 8 SO
MAX5035CUPA 0°C to +85°C 8 PDIP
MAX5035DUSA 0°C to +85°C 8 SO
MAX5035DUPA 0°C to +85°C 8 PDIP

PIN­PACKAGE

OUTPUT

VOLTAGE

(V)

3.3

5.0

12

ADJ

TOP VIEW

1

BST

VD

2

SGND

FB

MAX5035

3

4

SO/PDIP

8

7

6

5

LX

V

IN

GND

ON/OFF

MAX5035

1A, 76V, High-Efficiency MAXPower
Step-Down DC-DC Converter

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

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.

(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...........................................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

Storage Temperature Range .............................-65°C to +150°C

Junction Temperature......................................................+150°C

Lead Temperature (soldering, 10s) .................................+300°C

ELECTRICAL CHARACTERISTICS

(VIN= +12V, V

ON/OFF

= +12V, I

OUT

= 0, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C. See the

Typical Application Circuit.)

Input Voltage Range V

Undervoltage Lockout UVLO 5.2 V

Output Voltage V

Feedback Voltage V

Quiescent Supply Current I

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

MAX5035A 7.5 76.0

MAX5035B 7.5 76.0

IN

MAX5035C 15 76

MAX5035D 7.5 76.0

V

IN

I

OUT

V

IN

I

OUT

V

IN

I

OUT

= 0.5A, MAX5035A 86

LOAD

= 0.5A, MAX5035B 90

LOAD

= 0.5A, MAX5035C 94Efficiency η

LOAD

= 5V, I

OUT

OUT

FB

Q

MAX5035A

MAX5035B

MAX5035C

VIN = 7.5V to 76V, MAX5035D 1.192 1.221 1.250 V

VIN = 12V, I

VIN = 12V, I

VIN = 24V, I

V

= 12V, V

IN

MAX5035D

VFB = 3.5V, VIN = 7.5V to 76V, MAX5035A 350 460

VFB = 5.5V, VIN = 7.5V to 76V, MAX5035B 350 460

VFB = 13V, VIN = 15V to 76V, MAX5035C 350 460

VFB = 1.3V, MAX5035D 350 460

= 7.5V to 76V,

= 20mA to 1A

= 7.5V to 76V,

= 20mA to 1A

= 15V to 76V,

= 20mA to 1A

= 0.5A,

LOAD

3.185 3.3 3.415

4.85 5.0 5.15

11.64 12 12.36

90

V

V

%

µA

MAX5035

1A, 76V, High-Efficiency MAXPower

Step-Down DC-DC Converter

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VIN= +12V, V

ON/OFF

= +12V, I

OUT

= 0, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C. See the

Typical Application Circuit.)

)

Note 1: Switch current at which current limit is activated.

Shutdown Current I

Peak Switch Current Limit I

Switch Leakage Current I

Switch On-Resistance R

PFM Threshold I

FB Input Bias Current I

ON/OFF CONTROL INPUT

ON/OFF Input-Voltage Threshold V
ON/OFF Input-Voltage Hysteresis V
ON/OFF Input Current I

OSCILLATOR

Oscillator Frequency f

Maximum Duty Cycle D

VOLTAGE REGULATOR

Regulator Output Voltage VD VIN = 8.5V to 76V, IL = 0mA 6.9 7.8 8.8 V
Dropout Voltage 7.5V ≤ VIN ≤ 8.5V, IL = 1mA 2.0 V
Load Regulation ∆VD/∆IVD0 to 5mA 150 mV/mA

PACKAGE THERMAL CHARACTERISTICS

Thermal Resistance
(Junction to Ambient)

THERMAL SHUTDOWN

Thermal-Shutdown Junction
Temperature

Thermal-Shutdown Hysteresis T

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

SHDN

LIM

OL

DS(ON

PFM

ON/OFF

HYST

ON/OFFVON/OFF

OSC

MAX

θ

JA

T

SH

HYST

V

(Note 1) 1.80 2.40 A

VIN = 76V, V

I

Minimum switch current in any cycle 55 85 110 mA

MAX5035D -12 +0.01 +12 nA

B

Rising trip point 1.53 1.69 1.85 V

MAX5035D 95 %

SO package (JEDEC 51) 170

DIP package (JEDEC 51) 110

= 0V, VIN = 7.5V to 76V 10 45 µA

ON/OFF

= 0V, VLX = 0V 1 µA

ON/OFF

= 1A 0.40 0.80 Ω

SWITCH

100 mV

= 0V to V

IN

109 125 135 kHz

10 150 nA

+160 °C

20 °C

°C/W

MAX5035

1A, 76V, High-Efficiency MAXPower
Step-Down DC-DC Converter

4 _______________________________________________________________________________________

Typical Operating Characteristics

(VIN= 12V, V

ON/OFF

= 12V, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C. See the Typical Application

Circuit, if applicable.)

OUTPUT VOLTAGE vs. TEMPERATURE

(MAX5035AUSA, V

3.40

I

= 0.1A

OUT

3.36

3.32

(V)

OUT

V

3.28

3.24

3.20

0 100

OUTPUT VOLTAGE vs. TEMPERATURE

OUT

I

= 1A

OUT

5025

TEMPERATURE (°C)

= 3.3V)

75

MAX5035 toc01

5.20

(MAX5035DUSA, V

5.15

5.10

I

= 0.1A

OUT

I

= 1A

OUT

0 100

25 50

TEMPERATURE (°C)

(V)

V

OUT

5.05

5.00

4.95

4.90

4.85

4.80

OUT

= 5V)

MAX5035 toc02

75

LINE REGULATION

I

OUT

OUT

= 1A

= 3.3V)

MAX5035 toc03

65503520

3.40

(MAX5035AUSA, V

I

= 0.1A

OUT

3.36

3.32

3.28

OUTPUT VOLTAGE (V)

3.24

3.20
580

INPUT VOLTAGE (V)

LINE REGULATION

5.20

(MAX5035DUSA, V

5.15

5.10

5.05

I

= 0.1A

OUT

5.00

4.95

OUTPUT VOLTAGE (V)

4.90

4.85

4.80

580

INPUT VOLTAGE (V)

= 5V)

OUT

MAX5035 toc04

(V)

OUT

I

= 1A

OUT

655020 35

V

(MAX5035AUSA, V

3.40

VIN = 76V

3.36

VIN = 7.5V, 24V

3.32

3.28

3.24

3.20
0 1000

LOAD REGULATION

OUT

I

(mA)

LOAD

= 3.3V)

800600400200

MAX5035 toc05

LOAD REGULATION

5.10

(MAX5035DUSA, V

5.05

(V)

5.00

OUT

V

VIN = 76V

4.95

4.90
0 1000

I

LOAD

OUT

VIN = 24V

VIN = 7.5V

(mA)

= 5V)

MAX5035 toc06

800600400200

MAX5035

1A, 76V, High-Efficiency MAXPower

Step-Down DC-DC Converter

_______________________________________________________________________________________ 5

Typical Operating Characteristics (continued)

(VIN= 12V, V

ON/OFF

= 12V, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C. See the Typical Application

Circuit, if applicable.)

EFFICIENCY vs. LOAD CURRENT

(MAX5035AUSA, V

100

90

80

70

60

50

40

EFFICIENCY (%)

30

20

10

VIN = 48V

VIN = 76V

0

0 1000

VIN = 12V

VIN = 24V

LOAD CURRENT (mA)

OUTPUT CURRENT LIMIT

vs. TEMPERATURE

2.0

1.5

1.0

0.5

OUTPUT CURRENT LIMIT (A)

0

0 100

5025

TEMPERATURE (°C)

= 3.3V)

OUT

VIN = 7.5V

MAX5035DUSA

= 5V

V

OUT

5% DROP IN V

EFFICIENCY vs. LOAD CURRENT

100

(MAX5035DUSA, V

90

MAX5035 toc07

80

70

60

50

40

EFFICIENCY (%)

30

20

10

800600400200

VIN = 48V

VIN = 76V

0

0 1000

VIN = 12V

VIN = 24V

LOAD CURRENT (mA)

OUT

VIN = 7.5V

= 5V)

MAX5035 toc08

EFFICIENCY (%)

800600400200

OUTPUT CURRENT LIMIT

vs. INPUT VOLTAGE

2.0

MAX5035 toc10

1.7

1.4

1.1

OUTPUT CURRENT LIMIT (A)

0.8

OUT

75

0.5
580

INPUT VOLTAGE (V)

MAX5035DUSA

V

5% DROP IN VOUT

65503520

OUT

= 5V

MAX5035 toc11

QUIESCENT SUPPLY CURRENT (µA)

EFFICIENCY vs. LOAD CURRENT

(MAX5035DUSA, V

100

90

80

70

60

50

40

VIN = 76V

30

20

10

0

0 1000

VIN = 15V

VIN = 24V

VIN = 48V

LOAD CURRENT (mA)

OUT

= 12V)

QUIESCENT SUPPLY CURRENT

vs. TEMPERATURE

350

320

290

260

230

200

0 100

25

TEMPERATURE (°C)

7550

MAX5035 toc09

800600400200

MAX5035 toc12

QUIESCENT SUPPLY CURRENT

SHUTDOWN CURRENT

vs. INPUT VOLTAGE

MAX5035 toc13

20

16

12

8

SHUTDOWN CURRENT (µA)

4

0

0 100

350

320

290

260

230

QUIESCENT SUPPLY CURRENT (µA)

200

676

INPUT VOLTAGE (V)

665646362616

vs. TEMPERATURE

TEMPERATURE (°C)

SHUTDOWN CURRENT vs. INPUT VOLTAGE

20

MAX5035 toc14

16

12

8

SHUTDOWN CURRENT (µA)

4

755025

0

676

INPUT VOLTAGE (V)

MAX5035 toc15

665646362616

MAX5035

1A, 76V, High-Efficiency MAXPower
Step-Down DC-DC Converter

6 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(VIN= 12V, V

ON/OFF

= 12V, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C. See the Typical Application

Circuit, if applicable.)

MAX5035DUSA

LOAD-TRANSIENT RESPONSE

MAX5035 toc19

400µs/div

B

A

A: V

OUT

, 200mV/div, AC-COUPLED

B: V

OUT

, 500mA/div, 0.1A TO 0.5A

V

OUT

= 5V

MAX5035DUSA LX WAVEFORMS

MAX5035 toc20

4µs/div

B

0

A

0

A: SWITCH VOLTAGE (LX PIN), 20V/div, (VIN = 48V)
B: INDUCTOR CURRENT, 500mA/div (I

OUT

= 1A)

MAX5035DUSA LX WAVEFORMS

MAX5035 toc21

4µs/div

B

0

A

0

A: SWITCH VOLTAGE (LX PIN), 20V/div, (VIN = 48V)
B: INDUCTOR CURRENT, 200mA/div (I

OUT

= 100mA)

OUTPUT VOLTAGE

vs. INPUT VOLTAGE

15

MAX5035DUSA

= 12V

V

OUT

= V

V

12

ON/OFF

IN

9

(V)

OUT

V

6

3

0

015

I

OUT

VIN (V)

= 0

MAX5035DUSA

LOAD-TRANSIENT RESPONSE

V

= 5V

OUT

MAX5035 toc16

I

= 1A

OUT

I

= 0.3A

OUT

12963

, 200mV/div, AC-COUPLED

A: V

OUT

, 500mA/div, 0.1A TO 1A

B: I

OUT

400µs/div

MAX5035 toc17

V

A

B

A: V
B: V

MAX5035DUSA

LOAD-TRANSIENT RESPONSE

= 5V

OUT

400µs/div

, 200mV/div, AC-COUPLED

OUT

, 500mA/div, 0.5A TO 1A

OUT

MAX5035 toc18

A

B