Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - LDO voltage regulator Positivbe, adjustable uDFN 6 (1.5x1.0)

19-0629; Rev 1; 1/07

MAX8840/MAX8841/

MAX8842

Ultra-Low-Noise, High PSRR, Low-Dropout,

150mA Linear Regulators in µDFN

For pricing, delivery, and ordering information, please contact Maxim Direct

at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.

General Description

The MAX8840/MAX8841/MAX8842 ultra-low-noise, low-

dropout (LDO) linear regulators are designed to deliver

up to 150mA continuous output current. These regula-

tors achieve a low 120mV dropout for 120mA load cur-

rent. The MAX8840 uses an advanced architecture to

achieve ultra-low output voltage noise of 11µV

RMS

and

PSRR of 54dB at 100kHz.

The MAX8841 does not require a bypass capacitor,

hence achieving the smallest PC board area. The

MAX8842 output voltage can be adjusted with an exter-

nal divider.

The MAX8840/MAX8841 are preset to a variety of volt-

ages in the 1.5V to 4.5V range. Designed with a p-channel

MOSFET series pass transistor, the MAX8840/MAX8841/

MAX8842 maintain very low ground current (40µA).

The regulators are designed and optimized to work with

low-value, low-cost ceramic capacitors. The MAX8840

requires only 1µF (typ) of output capacitance for stability

with any load. When disabled, current consumption drops

to below 1µA.

The MAX8840/MAX8841/MAX8842 are available in a tiny

1.0mm x 1.5mm x 0.8mm µDFN.

Applications

Cellular and Cordless Phones

PDA and Palmtop Computers

Base Stations

Bluetooth Portable Radios and Accessories

Wireless LANs

Digital Cameras

Personal Stereos

Portable and Battery-Powered Equipment

Features

o Space-Saving 1.0mm x 1.5mm x 0.8mm µDFN

o 11µV

RMS

Output Noise at 100Hz to 100kHz

Bandwidth (MAX8840)

o 78dB PSRR at 1kHz (MAX8840)

o 120mV Dropout at 120mA Load

o Stable with 1µF Ceramic Capacitor for Any Load

o Guaranteed 150mA Output

o Only Need Input and Output Capacitors (MAX8841)

o Output Voltages: 1.5V, 1.8V, 2.5V, 2.6V, 2.7V, 2.8V,

2.85V, 3V, 3.3V, 4.5V (MAX8840/MAX8841) and

Adjustable (MAX8842)

o Low 40µA Ground Current

o Excellent Load/Line Transient

o Overcurrent and Thermal Protection

µDFN

(1.5mm x 1.0mm)

TOP VIEW

GND

BP (MAX8840)

N.C. (MAX8841)

FB (MAX8842)

SHDN

OUT

N.C.

MAX8840

MAX8841

MAX8842

Pin Configuration

Ordering Information

MAX8840

OUTPUT PRESET

1.5V TO 4.5V

INPUT

2V TO 6V

OFF

SHDN

10nF

OUT

1µF

OUT

GND

Typical Operating Circuits

xy is the output voltage code (see the Output Voltage Selector

Guide). Other versions between 1.5V and 4.5V are available in

100mV increments. Contact factory for other versions.

Denotes lead-free package.

PART* TEMP RANGE PIN-PACKAGE

MAX8840ELTxy+T -40°C to +85°C

6 µDFN-6

1.5mm x 1.0mm

MAX8841ELTxy+T -40°C to +85°C

6 µDFN-6

1.5mm x 1.0mm

MAX8842ELT+T -40°C to +85°C

6 µDFN-6

1.5mm x 1.0mm

Typical Operating Circuits continued at end of data sheet.

Output Voltage Selector Guide appears at end of data sheet.

Summary of content (11 pages)

PAGE 1
MAX8840/MAX8841/ MAX8842 Ultra-Low-Noise, High PSRR, Low-Dropout, 150mA Linear Regulators in µDFN General Description The MAX8840/MAX8841/MAX8842 ultra-low-noise, lowdropout (LDO) linear regulators are designed to deliver up to 150mA continuous output current. These regulators achieve a low 120mV dropout for 120mA load current. The MAX8840 uses an advanced architecture to achieve ultra-low output voltage noise of 11µVRMS and PSRR of 54dB at 100kHz.
PAGE 2
MAX8840/MAX8841/MAX8842 Ultra-Low-Noise, High PSRR, Low-Dropout, 150mA Linear Regulators in µDFN ABSOLUTE MAXIMUM RATINGS θJA ..................................................................................477°C/W Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................
PAGE 3
MAX8840/MAX8841/MAX8842 Ultra-Low-Noise, High PSRR, Low-Dropout, 150mA Linear Regulators in µDFN ELECTRICAL CHARACTERISTICS (continued) (VIN = VOUT + 0.5V, TA = -40°C to +85°C, unless otherwise noted. CIN = 1µF, COUT = 1µF, CBP = 10nF. Typical values are at +25°C; the MAX8842 is tested with 2.45V output, unless otherwise noted.
PAGE 4
MAX8840/MAX8841/MAX8842 Ultra-Low-Noise, High PSRR, Low-Dropout, 150mA Linear Regulators in µDFN Typical Operating Characteristics (continued) (VIN = VOUT + 0.5V, CIN = 1µF, COUT = 1µF, CBP = 10nF, TA = +25°C, unless otherwise noted.) TA = +85°C 120 100 TA = -40°C 80 60 200 150 100 MAX8840 GROUND PIN CURRENT vs. INPUT VOLTAGE 350 300 GROUND PIN CURRENT (μA) 140 MAX8840 toc05 TA = +25°C IOUT = 80mA DROPOUT VOLTAGE (mV) 0 0 0 25 50 75 100 125 2.2 2.4 2.6 2.8 3.0 3.
PAGE 5
MAX8840/MAX8841/MAX8842 Ultra-Low-Noise, High PSRR, Low-Dropout, 150mA Linear Regulators in µDFN Typical Operating Characteristics (continued) (VIN = VOUT + 0.5V, CIN = 1µF, COUT = 1µF, CBP = 10nF, TA = +25°C, unless otherwise noted.) MAX8840 toc15 MAX8840 toc14 MAX8840 toc13 25 20 OUTPUT NOISE (μV) MAX8840 LOAD-TRANSIENT RESPONSE NEAR DROPOUT MAX8840 LOAD-TRANSIENT RESPONSE MAX8840 OUTPUT NOISE vs. BP CAPACITANCE VIN = 3.1V ILOAD = 0 TO 50mA VIN = 3.
PAGE 6
MAX8840/MAX8841/MAX8842 Ultra-Low-Noise, High PSRR, Low-Dropout, 150mA Linear Regulators in µDFN Pin Description PIN MAX8842 NAME FUNCTION MAX8840 MAX8841 1 1 1 IN 2 2 2 GND Ground 3 3 3 SHDN Shutdown. Pull low to disable the regulator. 4 — — BP Noise Bypass for Low-Noise Operation. Connect a 10nF capacitor from BP to OUT. It is shorted to OUT in shutdown mode. — — 4 FB Adjustable Output Feedback Point 5 4, 5 5 N.C. No Connection. Not internally connected.
PAGE 7
MAX8840/MAX8841/MAX8842 Ultra-Low-Noise, High PSRR, Low-Dropout, 150mA Linear Regulators in µDFN For design purposes, consider the current limit to be 150mA (min) to 300mA (max). The output can be shorted to ground for an indefinite amount of time without damaging the part. Thermal-Overload Protection Thermal-overload protection limits total power dissipation in the MAX8840/MAX8841/MAX8842.
PAGE 8
MAX8840/MAX8841/MAX8842 Ultra-Low-Noise, High PSRR, Low-Dropout, 150mA Linear Regulators in µDFN Functional Diagram IN SHDN SHUTDOWN AND POWER-ON CONTROL MAX8840 MAX8841 MAX8842 ERROR AMP MOS DRIVER WITH ILIMIT P OUT ** THERMAL SENSOR 1.
PAGE 9
MAX8840/MAX8841/MAX8842 Ultra-Low-Noise, High PSRR, Low-Dropout, 150mA Linear Regulators in µDFN Typical Operating Circuits (continued) INPUT 2V TO 6V IN OUT CIN 1µF ON OFF OUTPUT PRESET 1.5V TO 4.5V MAX8841 SHDN COUT 1µF GND INPUT 2V TO 6V CIN 1µF ON OFF IN OUT MAX8842 OUTPUT ADJUSTABLE 1.5V TO 4.5V R1 FB SHDN GND COUT 1µF R2 Output Voltage Selector Guide PART VOUT (V) TOPMARK MAX8840ELT16+T 1.6 MN MAX8840ELT18+T 1.8 MO MAX8840ELT19+T 1.9 LX MAX8840ELT25+T 2.
PAGE 10
MAX8840/MAX8841/MAX8842 Ultra-Low-Noise, High PSRR, Low-Dropout, 150mA Linear Regulators in µDFN Package Information TOPMARK 3 2 5 e A 4 b 5 4 AA PIN 1 MARK 6L UDFN.EPS For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. 6 PIN 1 0.
PAGE 11
MAX8840/MAX8841/MAX8842 Ultra-Low-Noise, High PSRR, Low-Dropout, 150mA Linear Regulators in µDFN Package Information (continued) For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status.