MAXIM MAX5008 User Manual

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General Description

The MAX5008 charge-pump regulator generates a reg­ulated 5V output up to 125mA with a 2.95V to 5.5V input
voltage range. The device includes resistor-program­mable overcurrent limit. The MAX5008 requires a mini­mum number of external components for normal
operation. The high 1MHz switching frequency allows
the use of small surface-mount ceramic capacitors.

The fault-protection circuitry limits the output current
when it exceeds the limit set by an external resistor.
The output current can range from 1mA to 150mA to
accommodate circuit requirements. A FAULT output
indicates when the device is in current limit or the out­put is out of regulation.

A low-power shutdown mode reduces supply current to
less than 1µA and places the output in a high-imped­ance state. The MAX5008 is offered in a space-saving
10-pin µMAX package that is only 1.1mm high.

Applications

Flash Memory Supplies

USB Host Devices

Battery-Powered Systems

3.3V to 5V Local Conversion

Features

♦ Regulated 5V Output Up to 125mA

♦ Indefinite Short-Circuit Protection

♦ Adjustable Output Current Limit

♦ No Inductors Required

♦ 0.1µA Shutdown Current

♦ Thermal Shutdown

♦ Fault Output Indicates Overcurrent or Output

Voltage Out of Regulation

♦ 2.95V to 5.5V Input Voltage Range

♦ 10-Pin µMAX Package

MAX5008

Regulated 5V USB Charge Pump with

Programmable Current Limit

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-2426; Rev 0; 4/02

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.

Typical Operating Circuit

Pin Configuration appears at end of data sheet.

PART TEMP RANGE PIN-PACKAGE

MAX5008CUB 0°C to +70°C 10 µMAX

C

X

0.68µF

7

V

IN

2.95V TO 5.5V

4.7µF

100kΩ

*USE IF PRECISION CURRENT LIMIT IS REQUIRED.

CXN

8

IN

5

SHDN

3

FAULT

GND PGND

46

MAX5008

9

CXP

CEXT

OUT

RCS

200Ω*

2

R

47nF*

1

200Ω*

10

I

OUT

CS

0.4Ω

C

6.8µF

EXT

C

OUT

4.7µF

V

OUT

5V

MAX5008

Regulated 5V USB Charge Pump with
Programmable Current Limit

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VIN= SHDN = 3V, CIN= 4.7µF, CX= 0.68µF, C

EXT

= 6.8µF, C

OUT

= 4.7µF, RCS= 0.4Ω, TA= 0°C to +70°C, unless otherwise noted.

Typical values are at T

A

= +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.

IN, SHDN, RCS, FAULT, OUT to GND .....................-0.3V to +6V

PGND to GND.....................................................................±0.3V

CXN to GND ................................................-0.3V to (V

IN

+ 0.3V)

CXP to GND ............................................-0.3V to (V

CEXT

+ 0.3V)

CEXT to GND ..........................................-0.3V to (V

CEXT

+ 0.3V)

Short-Circuit Duration to GND .......................................Indefinite

Continuous Power Dissipation (T

A

= +70°C)

10-Pin µMAX.................................................................444mW

Operating Temperature Range...............................0°C to +70°C

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

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

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

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Input Voltage Range
(Note 1)

V

IN

Input Undervoltage Lockout
Threshold

Input Undervoltage Lockout
Hysteresis

Output Voltage
(Note 2)

Output Voltage Ripple V

V

Fault Threshold V

OUT

Maximum Output Current I

No-Load Input Current I

SHDN Logic High V
SHDN Logic Low V

Shutdown Supply Current I

Current-Sense Trip Level V

V

OUT

RIP

TH

OUT

Q

INH,SHDN

INL,SHDN

QSHDN

CS

FAULT Leakage Current V
FAULT Logic Low I

FAULT Assertion Delay

(Note 4)
FAULT Deassertion Delay (Note 5) t

t

FD

FDD

Switching Frequency 0.5 1 1.5 MHz

Startup Time t

START

I

= 125mA 2.95 4.25

OUT

I

= 70mA 2.95 5.50

OUT

Rising edge 2.0 2.35 2.6 V

Falling edge 100 mV

0 ≤ I

0mA ≤ I

0mA ≤ I

V

I

OUT

I

OUT

< 30mA, 2.95V < V

OUT

≤ 100mA, 2.95V ≤ V

OUT

≤ 125mA 100 mV

OUT

= 5V ±4% 100 140 mA

OUT

< 5.5V 4.75 5.0 5.30

IN

≤ 4.25V 4.75 5.0 5.25

IN

= 0, VIN = 4.25V 0.6 6

= 0, VIN = 3.3V 1 6

SHDN = low 0.1 10 µA

V

= I

x R

CS

OUT

= 5V, OUT in regulation 1 µA

FAULT

> I

OUT

LIMIT

I

> I

OUT

LIMIT

< V

V

OUT

TH

I

< I

OUT

LIMIT

V

> VTH, R

OUT

(Note 3) 55 60 73 mV

CS

, or V

and V

< VTH, I

OUT

OUT

= 46Ω, from rising edge

LOAD

FAULT

> 4.5V 16 ms

= 1mA 0.4 V

of SHDN

4.22 4.50 V

2.4 V

0.4 V

2ms

30 µs

200 µs

V

V

mA

MAX5008

Regulated 5V USB Charge Pump with

Programmable Current Limit

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VIN= SHDN = 3V, CIN= 4.7µF, CX= 0.68µF, C

EXT

= 6.8µF, C

OUT

= 4.7µF, RCS= 0.4Ω, TA= 0°C to +70°C, unless otherwise noted.

Typical values are at T

A

= +25°C.)

Note 1: When the input exceeds 4.25V, the power dissipation on the chip exceeds the maximum rating if the output current is 125mA.
Note 2: The MIN/MAX limits are 100% production tested at +25°C and +70°C, and guaranteed by design at 0°C.
Note 3: I

OUT

is output current flowing from C

EXT

.

Note 4: The delay from the fault event to the assertion of FAULT. Fault delays are specified with either a current fault or a voltage

fault, but not both simultaneously.

Note 5: The delay from the removal of the fault event to the deassertion of FAULT.

Typical Operating Characteristics

(VIN= 3V, CIN= 4.7µF, CX= 0.47µF, C

OUT

= 4.7µF, C

EXT

= 4.7µF, RCS= 0.4Ω, TA= +25°C, unless otherwise noted.)

NO-LOAD SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX5008 toc01

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

5.04.54.03.53.0

0.5

1.0

1.5

2.0

0

2.5 5.5

OUTPUT VOLTAGE

vs. LOAD CURRENT

MAX5008 toc02

LOAD CURRENT (mA)

OUTPUT VOLTAGE (V)

10010

4.7

4.9

5.1

5.3

5.5

4.5
11000

VIN = 2.9V

VIN = 5.0V

VIN = 3.3V

OUTPUT VOLTAGE

vs. SUPPLY VOLTAGE

MAX5008 toc03

SUPPLY VOLTAGE (V)

OUTPUT VOLTAGE (V)

54321

1

2

3

4

5

6

0

06

I

LOAD

= 100mA

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Thermal Shutdown
Junction Temperature

Thermal Shutdown Hysteresis 30 °C

150 °C