MAX8516EUB/V+ - Maxim

General Description

The MAX8516/MAX8517/MAX8518 low-dropout linear

regulators operate from input voltages as low as 1.425V

and are able to deliver up to 1A of continuous output

current with a maximum dropout voltage of only 200mV.

The output voltage can be set from 0.5V to (VIN - 0.2V)

and is 1.4% accurate over load and line variations, from

0°C to +85°C.

These regulators use small, 1µF ceramic input capaci-

tors and 4.7µF ceramic output capacitors to deliver 1A

output current. High bandwidth provides excellent tran-

sient response and limits the output voltage deviation to

45mV for a 20mA to 1A load step, with only a 4.7µF

ceramic output capacitor, and the voltage deviations can

be reduced further by increasing the output capacitor.

Designed with an internal p-channel MOSFET pass

transistor, the MAX8516/MAX8517/MAX8518 feature

low 340µA (typ) supply current during dropout condi-

tions. Soft-start reduces inrush current. Other features

include a logic-controlled shutdown mode, short-circuit

protection, and thermal-overload protection.

The MAX8517 features a power-OK (POK) output that

transitions high when the regulator output is within

±10% of its nominal output voltage. The MAX8518

features a 150ms power-on reset output.

The parts are packaged in a 10-pin µMAX®package that

includes an exposed pad for optimal power dissipation.

Applications

Servers

Storage

Networking

Base Stations

Optical Modules

Features

♦1.425V to 3.6V Input Voltage Range

♦Guaranteed 200mV Dropout at 1A Output Current

♦±1.4% Output Accuracy Over Load, Line, and

Temperature (0°C to +85°C), ±0.6% Initial Accuracy

♦Compatible with Ceramic Capacitors

♦Fast Transient Response

♦320µA Operating Supply Current

♦<25µA Shutdown Supply Current

♦Short-Circuit Protection

♦Thermal-Overload Protection

♦Soft-Start Limits Inrush Current

MAX8516/MAX8517/MAX8518

1.425V to 3.6V Input, 1A,

0.2V Dropout LDO Regulators

________________________________________________________________

Maxim Integrated Products

Ordering Information

19-3188; Rev 2; 9/09

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

EVALUATION KIT

AVAILABLE

PART TEMP RANGE PIN-PACKAGE

MAX8516EUB -40°C to +85°C 10 µMAX

MAX8517EUB -40°C to +85°C 10 µMAX

MAX8517EUB/V -40°C to +85°C 10 µMAX

MAX8518EUB -40°C to +85°C 10 µMAX

N.C.

OUT

FBN.C.

MAX8516

µMAX

TOP VIEW

GNDN.C.

N.C.

OUT

FBPOK

MAX8517

µMAX

GNDN.C.

N.C.

OUT

FBN.C.

MAX8518

µMAX

GNDPOR

Pin Configurations

MAX8516

MAX8517

MAX8518

1µF

4.7µF

INPUT

1.425V TO 3.6V

OUTPUT

0.5V TO (VIN - 0.2V), 1A

POWER-ON RESET

POWER-OK

OFF

IN_

POR (MAX8518)

POK (MAX8517)

EN GND

OUT_

Typical Operating Circuit

Post Regulators

Notebooks

PDAs

ATE

µMAX is a registered trademark of Maxim Integrated Products, Inc.

/V Denotes an automotive qualified part.

MAX8516/MAX8517/MAX8518

1.425V to 3.6V Input, 1A,

0.2V Dropout LDO Regulators

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(Circuit of Figure 1. VIN = +1.8V, VOUT = +1.5V, EN = IN, IOUT = 1mA, TA = -40°C to +85°C, unless otherwise noted.) (Note 1)

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, EN, POK (MAX8517), POR (MAX8518),

FB to GND .........................................................-0.3V to +4.0V

OUT to GND ..................................................-0.3V to (IN + 0.3V)

Output Short-Circuit Duration.....................................Continuous

Continuous Power Dissipation

(TA= +70°C, EP soldered to PCB)

10-Pin µMAX (derate 10.3mW/°C above +70°C) .........824mW

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

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

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

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

Soldering Temperature (reflow) .......................................+240°C

PARAMETER CONDITIONS MIN TYP MAX UNITS

Input Voltage Range 1.425 3.600 V

Input Undervoltage Lockout VIN rising, 70mV hysteresis 1.32 1.35 1.38 V

OUT

Output Voltage Range 0.5 3.4 V

Load Regulation IOUT = 1mA to 1A 0.1 %/A

Line Regulation VIN = 1.425V to 3.6V, VOUT = 1.225V, IOUT = 1mA -0.15 0 +0.15 % / V

Dropout Voltage (VIN - VOUT)V

IN = 1.425V, IOUT = 1A, VFB = 480mV 100 200 mV

Current Limit VIN = 3.6V, VOUT = 3V, VFB = 480mV 1.6 2 2.4 A

Output Shutdown Leakage VIN = 3.6V, VOUT = 0V, VEN = 0V 0.25 25 µA

IOUT = 10mA, TA = +85°C 497 500 503

FB Threshold Accuracy VOUT = 1.225V to 3V, VIN = VOUT + 0.2V to 3.6V,

IOUT = 1mA to 1A 493 507 mV

FB Input Bias Current VFB = 0.5V, VIN = 3.6V 0.001 1 µA

GND

VIN = 3.6V, VOUT = 3V, IOUT = 100mA 320

GND Supply Current Dropout, VIN = 3.6V, VFB = 480mV 340 600 µA

GND Shutdown Current VIN = 3.6V, EN = GND 0.25 25 µA

POK (MAX8517 ONLY)

FB high 540 550 560

POK Threshold VFB moving out of regulation,

VHYS = 10mV, IN = 1.425V to 3.6V FB low 440 450 460 mV

POK Output Voltage Low VFB = 0.4V or 0.6V, IPOK = 1mA 25 200 mV

POK Output Current High VPOK = 3.6V 0.001 1 µA

POK Fault Delay Time From FB to POK 25 50 100 µs

MAX8516/MAX8517/MAX8518

1.425V to 3.6V Input, 1A,

0.2V Dropout LDO Regulators

_______________________________________________________________________________________ 3

Note 1: Specifications to TA= -40°C are guaranteed by design, not production tested.

Note 2: Measurements at high current are pulse tested, such that the junction temperature is ambient temperature. Minimum supply

voltage for output accuracy must be at least 1.425V.

ELECTRICAL CHARACTERISTICS (continued)

(Circuit of Figure 1. VIN = +1.8V, VOUT = +1.5V, EN = IN, IOUT = 1mA, TA = -40°C to +85°C, unless otherwise noted.) (Note 1)

PARAMETER CONDITIONS MIN TYP MAX UNITS

POR (MAX8518 ONLY)

POR Reset Threshold VFB falling, VHYS = 10mV, VIN = 1.425V to 3.6V 440 450 460 mV

POR Output Voltage Low VFB = 0.4V or 0.6V, IPOR = 1mA 25 200 mV

POR Output Current High VPOR = 3.6V 0.001 1 µA

POR Rising Delay Time From FB to POR 105 150 210 ms

EN rising 1.2

Enable Input Threshold VIN = 1.425V to 3.6V EN falling 0.4 V

Enable Input Bias Current VEN = 0 or 3.6V -1 +1 µA

THERMAL SHUTDOWN

TJ rising +165

Thermal-Shutdown Threshold Output on or off TJ falling +150 °C

OUTPUT TRANSIENT

Load Transient IOUT = 20mA to 1A to 20mA, tRISE = tFALL = 1µs 3 %

Line Transient δVIN = 0.5V, tRISE = tFALL = 5µs 3 %

Typical Operating Characteristics

(Circuit of Figure 1, VIN = +1.8V, VOUT = +1.5V, IOUT = 1A, COUT = 4.7µF, CIN = 1µF, TA= +25°C.)

OUTPUT VOLTAGE

vs. INPUT VOLTAGE

MAX8516/17/18 toc01

INPUT VOLTAGE (V)

OUTPUT VOLTAGE (V)

3.02.41.81.20.6

1.35

1.40

1.45

1.50

1.55

1.60

1.30

03.6

TA = -40°C TO +85°C

OUTPUT VOLTAGE

vs. LOAD CURRENT

MAX8516/17/18 toc02

LOAD CURRENT (mA)

OUTPUT VOLTAGE (V)

800600400200

1.492

1.494

1.496

1.498

1.500

1.502

1.490

0 1000 1200

TA = +85°C

TA = +25°C

TA = -40°C

GROUND CURRENT

vs. INPUT VOLTAGE

MAX8516/17/18 toc03

INPUT VOLTAGE (V)

GROUND CURRENT (µA)

3.02.40.6 1.2 1.8

100

200

300

400

500

03.6

ILOAD = 1A

ILOAD = 0.5A

ILOAD = 0A

MAX8516/MAX8517/MAX8518

1.425V to 3.6V Input, 1A,

0.2V Dropout LDO Regulators

4 _______________________________________________________________________________________

GROUND CURRENT

vs. LOAD CURRENT

MAX8516/17/18 toc04

LOAD CURRENT (mA)

GROUND CURRENT (µA)

1000800600400200

275

300

325

350

375

250

0 1200

TA = +25°C

TA = -40°C

TA = +85°C

DROPOUT VOLTAGE

vs. LOAD CURRENT

MAX8516/17/18 toc05

LOAD CURRENT (mA)

DROPOUT VOLTAGE (mV)

800600400200

100

125

0 1000

LINE INPUT TRANSIENT

(VIN = +1.8V TO +2.5V, ILOAD = 1A)

MAX8516/17/18 toc06

100µs/div

VOUT

AC-COUPLED

20mV/div

VIN

AC-COUPLED

0.5V/div

LOAD-TRANSIENT RESPONSE

(ILOAD = 0.1A TO 1A)

MAX8516/17/18 toc07

40µs/div

VOUT

AC-COUPLED

50mV/div

ILOAD

1A/div

CIN = 220µF ELECTROLYTIC

CAP CLOSE TO IN

PSRR vs. FREQUENCY (MAX8516)

MAX8516/17/18 toc09

FREQUENCY (kHz)

PSRR (dB)

1001010.1

0.01 1000

ILOAD = 100mA

SHUTDOWN RESPONSE

MAX8516/17/18 toc08

100µs/div

VOUT

1V/div

2V/div

IIN

1A/div

Typical Operating Characteristics (continued)

(Circuit of Figure 1, VIN = +1.8V, VOUT = +1.5V, IOUT = 1A, COUT = 4.7µF, CIN = 1µF, TA= +25°C.)

MAX8516/MAX8517/MAX8518

1.425V to 3.6V Input, 1A,

0.2V Dropout LDO Regulators

_______________________________________________________________________________________

FB VOLTAGE vs. TEMPERATURE

MAX8516/17/18 toc10

TEMPERATURE (°C)

FB VOLTAGE (mV)

603510-15

499

500

501

502

498

-40 85

ILOAD = 10mA

OUTPUT RIPPLE VOLTAGE

MAX8516/17/18 toc11

100µs/div

VOUT

AC-COUPLED

1mV/div

OVERCURRENT THRESHOLD

vs. TEMPERATURE

MAX8516/17/18 toc12

TEMPERATURE (°C)

OVERCURRENT THRESHOLD (A)

603510-15

1.80

1.85

1.90

1.95

1.75

-40 85

SHORT-CIRCUIT CURRENT

MAX8516/17/18 toc13

100µs/div

VOUT

1V/div

IOUT

2A/div

CASE TEMPERATURE

vs. LOAD CURRENT

MAX8516/17/18 toc14

LOAD CURRENT (mA)

CASE TEMPERATURE (°C)

800600400200

0 1000

VIN = 2.5V; TA = +25°C

Typical Operating Characteristics (continued)

(Circuit of Figure 1, VIN = +1.8V, VOUT = +1.5V, IOUT = 1A, COUT = 4.7µF, CIN = 1µF, TA= +25°C.)

MAX8516/MAX8517/MAX8518

1.425V to 3.6V Input, 1A,

0.2V Dropout LDO Regulators

6 _______________________________________________________________________________________

Pin Description

MAX8516 MAX8517 MAX8518 NAME FUNCTION

111EN

Enable Input. Set low to place the device in low-current shutdown mode. Set

high for normal operation.

2, 3 2, 3 2, 3 IN Regulator Input. VIN can range from +1.425V to +3.6V. Bypass with a 1µF or

higher ceramic capacitor to GND.

4, 5, 10 5, 10 4, 10 N.C. No Connection. Pin 10 is internally pulled down to GND with a 10kΩ resistor.

Leave unconnected.

6 6 6 GND Ground

7 7 7 FB Feedback Pin. Connect to output through a voltage-divider to set the output.

8, 9 8, 9 8, 9 OUT

Regulator Output. Bypass with a 4.7µF ceramic capacitor to GND (a smaller

capacitor can be used if maximum load is less than 1A, i.e., COUT = IOUT

(max) x (1µF/200mA).

—4—POK

Power-OK Output (MAX8517 Only). Open-drain output. Connect to a positive

supply with a pullup resistor. If not used, leave pin unconnected. See the

Detailed Description.

—— 5POR

Power-On Reset Output. Open-drain output. Connect to a positive supply with

a pullup resistor. If not used, leave pin unconnected (see the Detailed

Description for more details).

———EP

Exposed Pad on the Underside of the Package. Solder to the ground plane for

proper heat dissipation.

MAX8516

MAX8517

MAX8518

POK

(MAX8517 ONLY)

POR

(MAX8518 ONLY)

GND

REF

OVERTHERMAL

PROTECTION

OVERTHERMAL

PROTECTION

UNDERVOLTAGE

LOCKOUT

THRESHOLD

0.55V

0.45V

0.50V

ERROR AMP

WITH

SOFT-START

MOS DRIVER

WITH ILIMIT

OUT

Functional Diagram

Detailed Description

The MAX8516/MAX8517/MAX8518 are low-input, low-

dropout, PMOS regulators capable of delivering up to

1A of output current with as little as 200mV of headroom

from input to output. The PMOS output stage can be dri-

ven from input voltages down to +1.425V without sacri-

ficing stability or transient performance. Since these

regulators have a PMOS output device, supply current

is not a significant function of load or input headroom.

Internal p-Channel Pass Transistor

The MAX8516/MAX8517/MAX8518 feature a 100mΩ(typ)

p-channel MOSFET pass transistor. Unlike similar

designs using pnp pass transistors, p-channel MOSFETs

require no base drive, which reduces quiescent current.

pnp-based regulators also waste considerable current in

dropout when the pass transistor saturates and use high

base-drive currents under large loads. The MAX8516/

MAX8517/MAX8518 do not suffer from these problems

and consume only 340µA (typ) of quiescent current

under heavy loads, as well as in dropout.

Short-Circuit/Thermal Fault Protection

The MAX8516/MAX8517/MAX8518 are fully protected

from a short circuit at the output through current-limiting

and thermal-overload circuitry. In the fault condition

when the output is shorted to ground, the output current

is limited to 2A. Under these conditions, the part quickly

heats up. When the junction temperature reaches

+165°C, the thermal-overload circuitry turns off the

output, allowing the part to cool down. When the junction

temperature cools to +150°C, the output turns back on

and tries to reestablish regulation. Current limiting and

thermal protection continue until the fault is removed. For

continuous operation, do not exceed the absolute maxi-

mum junction-temperature rating of TJ= +150°C.

Output Voltage Selection

The MAX8516/MAX8517/MAX8518 feature an

adjustable output voltage from 0.5V to 3.4V, using two

external resistors connected as a voltage-divider to FB

as shown in Figure 1. The output voltage is set by the

following equation:

where typically VFB = 0.5V. Choose R2 ≤5kΩto opti-

mize quiescent current, accuracy, and high-frequency

power-supply rejection. To simplify resistor selection:

Soft-Start

Inherent soft-start limits inrush current. Peak inrush cur-

rent is dependent on the value of COUT and can be cal-

culated as follows:

Shutdown Mode

The MAX8516/MAX8517/MAX8518 include an enable

input. To shut down the device, pull EN to GND. For

normal operation, connect the EN to IN. During shut-

down, an internal 10kΩresistor pulls down the output.

Power-OK (MAX8517 Only)

The MAX8517 features a power-OK (POK) output to

indicate the status of the output. POK remains high

when the regulator output is within ±10% of its nominal

output voltage. If the output voltage falls or rises out-

side this range, POK transitions low. This open-drain

output requires an external pullup resistor to IN. An

internal delay circuit prevents POK from switching for

50µs (typ) after the trip threshold is initially reached. If

the part is in shutdown mode, POK is low.

Power-On Reset (MAX8518 Only)

The MAX8518 features a power-on reset (POR) output

that transitions high 140ms (typ) after the output has

risen above 90% of its final value. This open-drain out-

put requires an external pullup resistor to IN. If the part

is in shutdown mode, falls below 90% of the nominal

output voltage, or experiences a short-circuit or thermal

fault, POR immediately transitions low.

INRUSH LOAD OUT

()

=+ µ

⎛

⎝

⎜⎞

⎠

⎟

OUT

12 1 =⎛

⎝

⎜

⎞

⎠

⎟

−

VV R

OUT FB

⎛

⎝

⎜⎞

⎠

⎟

MAX8516/MAX8517/MAX8518

1.425V to 3.6V Input, 1A,

0.2V Dropout LDO Regulators

_______________________________________________________________________________________ 7

MAX8516

MAX8517

MAX8518

1µF

4.7µF

ENABLE

SHUTDOWN

POK (MAX8517) OR

POR (MAX8518)

EN GND

OUT

100kΩ*

ADJUSTABLE

OUTPUT

*FOR MAX8517 AND MAX8518

+1.425V TO +3.6V

Figure 1. Typical Application Circuit

MAX8516/MAX8517/MAX8518

Operating Region and Power Dissipation

The maximum power dissipation depends on the ther-

mal resistance of the IC package and circuit board, the

temperature difference between the die junction and

ambient air, and the rate of airflow. The power dissipat-

ed in the device is P = IOUT ✕(VIN - VOUT).

The package features an exposed thermal pad on its

underside. This pad lowers the thermal resistance of

the package by providing a direct heat conduction

path from the die to the PCB.

Additionally, the ground pins (GND) perform the dual

function of providing an electrical connection to system

ground and channeling heat away. Connect the

exposed backside pad and GND to the system ground

using a large pad or ground plane, or multiple vias to

the ground plane layer.

Applications Information

Capacitor Selection and

Regulator Stability

Capacitors are required at the MAX8516/MAX8517/

MAX8518 inputs and outputs for stable operation over the

full temperature range and with load currents up to 1A.

Connect a 1µF capacitor between IN and ground and a

4.7µF capacitor with low equivalent series resistance

(ESR) between OUT and ground for 1A output current.

The input capacitor (CIN) lowers the source impedance of

the input supply. If input-supply source impedance is

high, place a larger input capacitor close to IN to prevent

VIN sagging due to load transients. Smaller output capac-

itors can be used for output currents less than 1A.

Calculate COUT as follows:

Noise, PSRR, and Transient Response

The MAX8516/MAX8517/MAX8518 are designed to

operate with low dropout voltages and low quiescent

currents while still maintaining good noise, transient

response, and AC rejection (see the

Typical Operating

Characteristics

for a plot of Power-Supply Rejection

Ratio (PSRR) vs. Frequency). When operating from

noisy sources, improved supply-noise rejection and

transient response can be achieved by increasing the

values of the input and output bypass capacitors and

through passive filtering techniques. The MAX8516/

MAX8517/MAX8518 load-transient response graphs

(see the

Typical Operating Characteristics

) show two

components of the output response: a DC shift from the

output impedance due to the load current change, and

the transient response. A typical transient overshoot for

a step change in the load current from 20mA to 1A is

45mV. Use larger output ceramic capacitors greater

than 4.7µF up to 50µF to attenuate the overshoot.

CI FmA

OUT OUT MAX

()

=×µ1 200

1.425V to 3.6V Input, 1A,

0.2V Dropout LDO Regulators

8 _______________________________________________________________________________________

MAX8516/MAX8517/MAX8518

1.425V to 3.6V Input, 1A,

0.2V Dropout LDO Regulators

_______________________________________________________________________________________ 9

Chip Information

TRANSISTOR COUNT: 2849

PROCESS: BiCMOS

Package Information

For the latest package outline information and land patterns, go

to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in

the package code indicates RoHS status only. Package draw-

ings may show a different suffix character, but the drawing per-

tains to the package regardless of RoHS status.

PACKAGE TYPE PACKAGE CODE DOCUMENT NO.

10 µMAX U10E-3 21-0109

MAX8516/MAX8517/MAX8518

1.425V to 3.6V Input, 1A,

0.2V Dropout LDO Regulators

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

Revision History

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

0 2/04 Initial release —

1 4/04 Removed future product asterisks for MAX8517/MAX8518. Updated

Electrical Characteristics and Pin Description.1–3, 6

2 9/09 Added MAX8517 automotive package to Ordering Information.1