Rainbow Electronics MAX8842 User Manual

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 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 exter­nal divider.

The MAX8840/MAX8841 are preset to a variety of volt­ages 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
1mm 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

♦ Space-Saving 1.0mm x 1.5mm x 0.8mm µDFN
♦ 11µV

RMS

Output Noise at 100Hz to 100kHz

Bandwidth (MAX8840)

♦ 78dB PSRR at 1kHz (MAX8840)
♦ 120mV Dropout at 120mA Load
♦ Stable with 1µF Ceramic Capacitor for Any Load
♦ Guaranteed 150mA Output
♦ Only Need Input and Output Capacitors (MAX8841)
♦ 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)

♦ Low 40µA Ground Current
♦ Excellent Load/Line Transient
♦ Overcurrent and Thermal Protection

MAX8840/MAX8841/MAX8842

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

150mA Linear Regulators in µDFN

________________________________________________________________ Maxim Integrated Products 1

Pin Configuration

Ordering Information

MAX8840

OUTPUT PRESET

1.5V TO 4.5V

IN

INPUT
2V TO 6V

OFF

SHDN

C

BP

10nF

C

OUT

1μF

C

IN

1μF

OUT

ON

BP

GND

Typical Operating Circuits

19-0629; Rev 1; 1/07

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.

*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.

Typical Operating Circuits continued at end of data sheet.

Output Voltage Selector Guide appears at end of data sheet.

PART* TEMP RANGE PIN-PACKAGE

MAX8840ELTxy+T -40°C to +85°C

MAX8841ELTxy+T -40°C to +85°C

MAX8842ELT+T -40°C to +85°C

6 µDFN-6

1.5mm x 1.0mm

6 µDFN-6

1.5mm x 1.0mm

6 µDFN-6

1.5mm x 1.0mm

TOP VIEW

1

IN

2

GND

3

SHDN

(1.5mm x 1.0mm)

OUT

6

MAX8840
MAX8841
MAX8842

μDFN

5

N.C.

BP (MAX8840)
N.C. (MAX8841)

4

FB (MAX8842)

MAX8840/MAX8841/MAX8842

Ultra-Low-Noise, High PSRR, Low-Dropout,
150mA Linear Regulators in µDFN

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VIN= V

OUT

+ 0.5V, TA = -40°C to +85°C, unless otherwise noted. CIN= 1µF, C

OUT

= 1µF, C

BP

= 10nF. Typical values are at +25°C;

the MAX8842 is tested with 2.45V output, 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 to GND .................................................................-0.3V to +7V

Output Short-Circuit Duration ............................................Infinite

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

FB, BP, N.C. to GND..................................-0.3V to (OUT + 0.3V)

Continuous Power Dissipation (T

A

= +70°C)

6-Pin µDFN (derate 2.1mW/°C above +70°C) .............0.168W

θ

JA

..................................................................................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) .................................+300°C

Input Voltage Range V

Maximum Output Current I

Current Limit I

Dropout Voltage (Note 2)

Ground Current I

Line Regulation V

Load Regulation V

Shutdown Supply Current I

Ripple Rejection PSRR

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

IN

I

= 1mA, TA = +25°C -1 +1

OUT

I

= 100µA to 80mA, TA = +25°C -2 +2Output Voltage Accuracy

OUT

= 100µA to 80mA -3 +3

I

OUT

OUT

LIM

LNR

LDR

SHDN

OUT = 90% of nominal value 150 200 300 mA

V

≥ 3V, I

OUT

V

≥ 3V, I

OUT

2.5V ≤ V

2.5V ≤ V
2V ≤ V

OUT

2V ≤ V

OUT

I

= 0.05mA 40 90

Q

OUT

VIN = V

OUT(nom)

VIN = (V

I

= 1mA to 80mA 0.003 %/mA

OUT

= 80mA 80 170

OUT

= 120mA 120

OUT

< 3V, I

OUT

OUT

< 2.5V, I

< 2.5V, I

< 3V, I

OUT

OUT

OUT

OUT

- 0.1V, I

+ 0.5V) to 6V, I

OUT

SHDN = 0V

f = 1kHz, I

f = 10kHz, I

f = 100kHz, I

OUT

OUT

OUT

= 10mA

= 10mA

= 10mA

26V

150 mA

= 80mA 90 200

= 120mA 135

= 80mA 120 250

= 120mA 180

= 0mA 220 500

OUT

= 0.1mA 0.001 %/V

OUT

TA = +25°C 0.003 1

= +85°C 0.05

T

A

MAX8840 78

MAX8841/MAX8842 72

MAX8840 75

MAX8841/MAX8842 65

MAX8840 54

MAX8841/ MAX8842 46

%

mV

µA

µA

dB

MAX8840/MAX8841/MAX8842

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

150mA Linear Regulators in µDFN

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VIN= V

OUT

+ 0.5V, TA = -40°C to +85°C, unless otherwise noted. CIN= 1µF, C

OUT

= 1µF, C

BP

= 10nF. Typical values are at +25°C;

the MAX8842 is tested with 2.45V output, unless otherwise noted.) (Note 1)

Note 1: Limits are 100% tested at +25°C. Limits over operating temperature range are guaranteed by design.
Note 2: Dropout is defined as V

IN

- V

OUT

when V

OUT

is 100mV below the value of V

OUT

for V

IN

= V

OUT

+ 0.5V.

Note 3: Time needed for V

OUT

to reach 90% of final value.

Typical Operating Characteristics

(VIN= V

OUT

+ 0.5V, CIN= 1µF, C

OUT

= 1µF, CBP= 10nF, TA= +25°C, unless otherwise noted.)

MAX8840

OUTPUT VOLTAGE vs. INPUT VOLTAGE

MAX8840 toc01

INPUT VOLTAGE (V)

OUTPUT VOLTAGE (V)

54321

0.5

1.0

1.5

2.0

2.5

3.0

3.5

0.0
06

I

OUT

= 150mA

I

OUT

= 0mA

MAX8840

OUTPUT VOLTAGE ACCURACY

vs. LOAD CURRENT

MAX8840 toc02

LOAD CURRENT (mA)

% DEVIATION (%)

125100755025

-0.4

-0.2

0

0.2

0.4

0.6

-0.6
0150

MAX8840

OUTPUT VOLTAGE ACCURACY

vs. TEMPERATURE

MAX8840 toc03

TEMPERATURE (°C)

% DEVIATION (%)

603510-15

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1.0

-1.0

-40 85

I

OUT

= 1mA

Output Noise Voltage
(RMS)

Shutdown Exit Delay R

SHDN Logic-Low Level V
SHDN Logic-High Level V

SHDN Input Bias Current

FB Input Bias Current
(MAX8842)

Thermal Shutdown 160 °C

Thermal-Shutdown
Hysteresis

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

f = 100Hz to 100kHz,

= 10mA

I

LOAD

f = 100Hz to 100kHz,

= 80mA

I

LOAD

= 50Ω (Note 3) 300 µs

LOAD

= 2V to 6V 0.4 V

IN

= 2V to 6V 1.5 V

IN

V

= 6V, SHDN = 0V or

IN

6V

V

= 6V, V

IN

FB

= 1.3V

MAX8840 11

MAX8841/MAX8842 230

MAX8840 13

MAX8841/MAX8842 230

TA = +25°C

= +85°C 0.01

T

A

TA = +25°C 0.006 0.1

T

= +85°C 0.01

A

10 °C

µV

µA

µA