Maxim MAX1676EUA, MAX1675EUA, MAX1674EUA Datasheet

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General Description

The MAX1674/MAX1675/MAX1676 compact, high-effi­ciency, step-up DC-DC converters fit in small µMAX
packages. They feature a built-in synchronous rectifier,
which improves efficiency and reduces size and cost
by eliminating the need for an external Schottky diode.
Quiescent supply current is only 16µA.

The input voltage ranges from 0.7V to V

OUT

, where

V

OUT

can be set from 2V to 5.5V. Start-up is guaran­teed from 1.1V inputs. The MAX1674/MAX1675/
MAX1676 have a preset, pin-selectable output for 5V or

3.3V. The outputs can also be adjusted to other volt­ages using two external resistors.

All three devices have a 0.3Ω N-channel MOSFET
power switch. The MAX1674 has a 1A current limit. The
MAX1675 has a 0.5A current limit, which permits the
use of a smaller inductor. The MAX1676 comes in a
10-pin µMAX package and features an adjustable cur­rent limit and circuitry to reduce inductor ringing.

________________________Applications

Pagers
Wireless Phones
Medical Devices
Hand-Held Computers
PDAs
RF Tags
1 to 3-Cell Hand-Held Devices

____________________________Features

♦ 94% Efficient at 200mA Output Current
♦ 16µA Quiescent Supply Current
♦ Internal Synchronous Rectifier (no external diode)
♦ 0.1µA Logic-Controlled Shutdown
♦ LBI/LBO Low-Battery Detector
♦ Selectable Current Limit for Reduced Ripple
♦ Low-Noise, Anti-Ringing Feature (MAX1676)
♦ 8-Pin and 10-Pin µMAX Packages
♦ Preassembled Evaluation Kit (MAX1676EVKIT)

MAX1674/MAX1675/MAX1676

High-Efficiency, Low-Supply-Current,

Compact, Step-Up DC-DC Converters

________________________________________________________________

Maxim Integrated Products

1

GNDLBO

SHDN

REF

1

2

8

7

OUT

LXLBI

FB

MAX1674
MAX1675

µMAX

TOP VIEW

3

4

6

5

1
2
3
4
5

10

9
8
7
6

OUT
LX
GND
BATTCLSEL

LBO

LBI

FB

MAX1676

µMAX

SHDNREF

MAX1674
MAX1675

INPUT

0.7V TO V

OUT

SHDN

LX

LBO

OUT

LBI

0.1µF

LOW-BATTERY
DETECT OUT

OFF

ON

REF

GND

FB

OUTPUT

3.3V, 5V, OR

ADJ (2V TO 5.5V)

UP TO 300mA

LOW-BATTERY

DETECT IN

PART

MAX1674EUA

-40°C to +85°C

TEMP. RANGE PIN-PACKAGE

8 µMAX

_______________Ordering Information

MAX1675EUA

-40°C to +85°C 8 µMAX

MAX1676EUB

-40°C to +85°C 10 µMAX

EVALUATION KIT

AVAILABLE

Typical Operating Circuit

Pin Configurations

19-1360; Rev 0; 7/98

MAX1674/MAX1675/MAX1676

High-Efficiency, Low-Supply-Current,
Compact, Step-Up DC-DC Converters

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(V

BATT

= 2V, FB = OUT (V

OUT

= 3.3V), RL= ˙∞, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°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.

Supply Voltage (OUT to GND) ..............................-0.3V to +6.0V

Switch Voltage (LX to GND).....................-0.3V to (V

OUT

+ 0.3V)

Battery Voltage (BATT to GND).............................-0.3V to +6.0V

SHDN, LBO to GND ..............................................-0.3V to +6.0V

LBI, REF, FB, CLSEL to GND...................-0.3V to (V

OUT

+ 0.3V)

Switch Current (LX)...............................................-1.5A to +1.5A

Output Current (OUT) ...........................................-1.5A to +1.5A

Continuous Power Dissipation (T

A

= +70°C)

8-Pin µMAX (derate 4.1mW/°C above +70°C) .............330mW

10-Pin µMAX (derate 5.6mW/°C above +70°C) ...........444mW

Operating Temperature Range ...........................-40°C to +85°C

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

Storage Temperature Range.............................-65°C to +165°C

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

TA= +25°C, RL= 3kΩ (Note 1)

VLX= 0, 5.5V; V

OUT

= 5.5V

TA= +25°C

MAX1675, MAX1676 (CLSEL = GND)

MAX1674, MAX1676 (CLSEL = OUT)

ILX= 100mA

FB = OUT
(V

OUT

= 3.3V)

V

OUT

= 2V to 5.5V

I

REF

= 0 to 100µA

90 130

MAX1675,
MAX1676 (CLSEL = GND)

FB = OUT
FB = GND

I

REF

= 0

CONDITIONS

µA

0.05 1

I

LEAK

LX Leakage Current

A

0.4 0.5 0.65

I

LIM

0.80 1 1.20

LX Switch Current
Limit (NFET)

Ω

0.3 0.6

R

DS(ON)

Internal NFET, PFET
On-Resistance

V

1.274 1.30 1.326

FB, LBI Input Threshold

mV/V

0.08 2.5

V

REF_LINE

Reference Voltage Line
Regulation

mV

3 15

V

REF_LOAD

Reference Voltage Load
Regulation

mV/°C

0.024

TEMPCOReference Voltage Tempco

V

1.274 1.30 1.326

V

REF

Reference Voltage

V

0.9 1.1

Start-Up Voltage

V

1.1 5.5

V

IN

V

0.7

Minimum Input Voltage
Operating Voltage

150 220

FB = GND
(V

OUT

= 5V)

MAX1675,
MAX1676 (CLSEL = GND)

180 285

I

OUT

MAX1674,
MAX1676 (CLSEL = OUT)

mA

300 420

Steady-State Output Current
(Note 2)

mV/°C

-2

Start-Up Voltage Tempco

V

3.17 3.30 3.43

V

OUT

Output Voltage

4.80 5 5.20

MAX1674,
MAX1676 (CLSEL = OUT)

V

2 5.5

Output Voltage Range

UNITSMIN TYP MAXSYMBOLPARAMETER

MAX1674/MAX1675/MAX1676

High-Efficiency, Low-Supply-Current,

Compact, Step-Up DC-DC Converters

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS

(V

BATT

= 2V, FB = OUT, RL= ∞, TA= -40°C to +85°C, unless otherwise noted.) (Note 4)

Note 1: Start-up voltage operation is guaranteed with the addition of a Schottky MBR0520 external diode between the input and

output.

Note 2: Steady-state output current indicates that the device maintains output voltage regulation under load. See Figures 5 and 6.
Note 3: Device is bootstrapped (power to the IC comes from OUT). This correlates directly with the actual battery supply.

V

OUT

= 2V, I

LOAD

= 1mA

V

OUT

= 3.3V, I

LOAD

= 200mA

SHDN = GND

CONDITIONS

%

85

Efficiency

90

µA

0.1 1

Shutdown Current into OUT

UNITSMIN TYP MAXSYMBOLPARAMETER

MAX1676, V

BATT

= 2V

V

LBO

= 5.5V, V

LBI

= 5.5V

V

LBI

= 0, I

SINK

= 1mA

V

SHDN

= 0 or V

OUT

VFB= 1V, V

OUT

= 3.3V

MAX1676, CLSEL = OUT

V

LBI

= 1.4V

VFB= 1.4V

VFB= 1V, V

OUT

= 3.3V

0.8V

OUT

V

IH

0.2V

OUT

V

IL

CLSEL Input Voltage

V

0.8V

OUT

V

IH

0.2V

OUT

V

IL

SHDN Input Voltage

Ω88 150Damping Switch Resistance

µA

0.07 1

I

LBO

LBO Off Leakage Current

V

0.2 0.4

LBO Low Output Voltage

nA

0.07 50

I

SHDN

SHDN Input Current

µA

1.4 3

I

CLSEL

CLSEL Input Current

nA

1 50

I

LBI

LBI Input Current

nA

0.03 50

I

FB

FB Input Current

µs

0.8 1 1.2

t

OFF

LX Switch Off-Time

µs

3 4 7

t

ON

LX Switch On-Time

V

ELECTRICAL CHARACTERISTICS (continued)

(V

BATT

= 2V, FB = OUT (V

OUT

= 3.3V), RL= ˙∞, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

FB = GND

FB = OUT

VFB= 1V, V

OUT

= 3.3V

VFB= 1V, V

OUT

= 3.3V

SHDN = GND

VFB= 1.4V, V

OUT

= 3.3V

I

REF

= 0

MAX1675, MAX1676 (CLSEL = GND)

MAX1674, MAX1676 (CLSEL = OUT)

CONDITIONS

0.36 0.69

A

0.75 1.25

I

LIM

LX Switch Current
Limit (NFET)

V2.20 5.5Output Voltage Range

V

4.75 5.25

3.13 3.47

V

OUT

Output Voltage

µs0.75 1.25t

OFF

LX Switch Off-Time

µs2.7 7.0t

ON

LX Switch On-Time

µA1Shutdown Current into OUT

µA40

Operating Current into OUT
(Note 3)

V1.2675 1.3325V

REF

Reference Voltage

V1.2675 1.3325FB, LBI Thresholds

Ω0.6R

DS(ON)

Internal NFET, PFET
On-Resistance

UNITSMIN MAXSYMBOLPARAMETER

VFB= 1.4V, V

OUT

= 3.3V µA

16 35

Operating Current into OUT
(Note 3)

MAX1674/MAX1675/MAX1676

High-Efficiency, Low-Supply-Current,
Compact, Step-Up DC-DC Converters

4 _______________________________________________________________________________________

Typical Operating Characteristics

(L = 22µH, CIN= 47µF, C

OUT

= 47µF0.1µF, C

REF

= 0.1µF, TA= +25°C, unless otherwise noted.)

V

LBO

= 5.5V, V

LBI

= 5.5V

V

SHDN

= 0 or V

OUT

MAX1676, CLSEL = OUT

CONDITIONS

µA1I

LBO

LBO Off Leakage Current

nA75I

SHDN

SHDN Input Current

µA3I

CLSEL

CLSEL Input Current

UNITSMIN MAXSYMBOLPARAMETER

ELECTRICAL CHARACTERISTICS (continued)

(V

BATT

= 2V, FB = OUT, RL= ∞, TA= -40°C to +85°C, unless otherwise noted.) (Note 4)

Note 4: Specifications to -40°C are guaranteed by design, not production tested.

100

0

0.01 0.1 1 10 100 1000

EFFICIENCY vs. LOAD CURRENT

20

30

10

MAX1674 toc01

LOAD CURRENT (mA)

EFFICIENCY (%)

40

50

60

70

90
80

VIN = 1.2V

V

OUT

= 5V

I

LIMIT

= 500mA

VIN = 2.4V

VIN = 3.6V

100

0

0.01 0.1 1 10 100 1000

EFFICIENCY vs. LOAD CURRENT

20

30

10

MAX1674 toc02

LOAD CURRENT (mA)

EFFICIENCY (%)

40

50

60

70

90
80

VIN = 1.2V

V

OUT

= 5V

I

LIMIT

= 1A

VIN = 2.4V

VIN = 3.6V

100

0

0.01 0.1 1 10 100 1000

EFFICIENCY vs. LOAD CURRENT

20

30

10

MAX1674 toc03

LOAD CURRENT (mA)

EFFICIENCY (%)

40

50

60

70

90
80

VIN = 1.2V

V

OUT

= 3.3V

I

LIMIT

= 500mA

VIN = 2.4V

100

0

0.01 0.1 1 10 100 1000

EFFICIENCY vs. LOAD CURRENT

20

30

10

MAX1674 toc04

LOAD CURRENT (mA)

EFFICIENCY (%)

40

50

60

70

90
80

VIN = 1.2V

V

OUT

= 3.3V

I

LIMIT

= 1A

VIN = 2.4V

1.290

1.292

1.296

1.294

1.298

1.300

-40 0-20 20 40 60 80 100

REFERENCE OUTPUT VOLTAGE

vs. TEMPERATURE

MAX1674 toc05

TEMPERATURE (°C)

REFERENCE OUTPUT VOLTAGE (V)

I

REF

= 0

I

REF

= 100µA