Maxim MAX8902, MAX8902B Datasheet

General Description

The MAX8902A/MAX8902B low-noise linear regulators
deliver up to 500mA of output current with only
16µV

RMS

of output noise in a 100kHz bandwidth. These
regulators maintain their output voltage over a wide
input range, requiring only 100mV of input-to-output
headroom at full load.

These LDOs maintain a low 80µA typical supply cur­rent, independent of the load current and dropout volt­age. The regulator control circuitry includes a
programmable soft-start circuit and short circuit,
reverse current, and thermal-overload protection. Other
features include an enable input and a power-OK out­put (MAX8902B only).

The MAX8902A output voltage can be set to 1.5V, 1.8V,

2.0V, 2.5V, 3.0V, 3.1V, 3.3V, 4.6V, or 4.7V using the
SELA and SELB inputs. The MAX8902B output voltage
can be set between 0.6V and 5.3V with an external
resistor voltage-divider.

Applications

Notebook Computers

MP3 and Portable Media Players

Wireless Headphones

GPS Portable Navigation Devices

Smartphones

Features

♦ 1.7V to 5.5V Input Voltage Range

♦ 0.6V to 5.3V Output Voltage Range

♦ 16µV

RMS

Output Noise, 10Hz to 100kHz

♦ 80µA Operating Supply Current

♦ 92dB PSRR at 5kHz

♦ Guaranteed 500mA Output Current

♦ ±1.5% Output Accuracy Over Load, Line, and

Temperature

♦ 100mV (max) Dropout at 500mA Load

♦ < 1µA Shutdown Supply Current

♦ 700mA Short-Circuit Protection

♦ Thermal-Overload Protection

♦ Output-to-Input Reverse Current Protection

♦ 2mm x 2mm x 0.8mm TDFN Package

MAX8902A/MAX8902B

Low-Noise 500mA LDO Regulators

in a 2mm x 2mm TDFN Package

________________________________________________________________

Maxim Integrated Products

1

19-0990; Rev 2; 2/08

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

Ordering Information

IN

EN

OUT

BYP

ON

OFF

OUTPUT

4.6V

SELB

SELA

OUTS

GND

EP

10μF

INPUT

4.7V TO 5.5V

0.01μF

10μF

MAX8902A

Typical Operating Circuits

PART FEATURES

TOP

MARK

PKG

CODE

MAX8902AATA+

Pin-selectable output
voltage

ABG T822-1

MAX8902BATA+

Adjustable output
voltage

ABH T822-1

+

Denotes a lead-free, RoHS-compliant package.

Note: All devices are in an 8-pin, 2mm x 2mm TDFN package
with an exposed paddle and operate over the -40°C to +125°C
automotive temperature range.

IN

EN

OUT

BYP

ON

OFF

OUTPUT ADJUSTABLE

0.6V TO 5.3V

GS

POK

FB

GND

EP

10μF

INPUT

1.7V TO 5.5V

0.01μF

10μF

MAX8902B

R1

R2

LOGIC
SUPPLY

R3

100kΩ

TO μC

Pin Configurations appear at end of data sheet.

MAX8902A/MAX8902B

Low-Noise 500mA LDO Regulators
in a 2mm x 2mm TDFN Package

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

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.

BYP, EN, IN, OUT, SELA, SELB, POK to GND, GS to GND, FB,

OUTS to GND .....................................................-0.3V to +6.0V

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

Continuous Power Dissipation (T

A

= +70°C)
8-Pin, 2mm x 2mm TDFN

(derate 11.9mW/°C above +70°C).............................953.5mW

Operating Temperature Range .........................-40°C to +125°C

Junction Temperature Range ............................-40°C to +150°C

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

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

ELECTRICAL CHARACTERISTICS

(VIN= VEN= 5V, OUTS = OUT, circuit of Figure 2 (MAX8902A) and Figure 3 (MAX8902B), TA= -40°C to +125°C, unless otherwise
noted.) (Note 1)

PARAMETER CONDITIONS MIN TYP MAX UNITS

IN

Input Voltage Range 1.7 5.5 V

Input Undervoltage Lockout VIN rising, 100mV typical hysteresis 1.5 1.6 1.7 V

OUT

Output Voltage Range VIN ≥ V

OUT

+ 0.1V 0.6 5.3 V

Output Voltage Accuracy

V

IN

= 1.7V to 5.5V for V

OUT

≤ 1.4V,

V

IN

= (V

OUT

+ 0.3V) to 5.5V for V

OUT

> 1.4V,

I

OUT

= 0.1mA to 500mA

-1.5 +1.5 %

Load Regulation I

OUT

= 0.1mA to 500mA 0.02 %

Line Regulation

V

IN

= 1.7V to 5.5V for V

OUT

≤ 1.4V,

V

IN

= (V

OUT

+ 0.3V) to 5.5V for V

OUT

> 1.4V,

I

OUT

= 200mA

0.04 %

VIN ≥ 3.6V, TA ≤ +85°C 50 100

VIN ≥ 3.6V, TA ≤ +125°C 120

Dropout Voltage
(Note 2)

I

OUT

= 500mA

V

IN

= 1.7V 150

mV

Current Limit V

OUT

= 95% of regulation, VIN = V

OUT

+ 0.5V 600 700 800 mA

Output Noise I

OUT

= 100mA, f = 10Hz to 100kHz, C

BYP

= 0.01µF 16 µV

RMS

f = 5kHz 92

f = 10kHz 85Power-Supply Rejection Ratio I

OUT

= 10mA

f = 100kHz 62

dB

OUTS (MAX8902A only)

OUTS Input Bias Current In regulation 0.5 7.0 µA

FB (MAX8902B only)

FB Threshold Accuracy VIN = 1.7V to 5.5V, I

OUT

= 0.1mA to 500mA 0.591 0.600 0.609 V

TA = +25°C -0.1 0.02 +0.1

FB Input Bias Current VFB = 0.6V

T

A

= -40°C 0.03

µA

BYP

BYP Capacitor Range Regulator remains stable 1 100 nF

BYP Startup Current From BYP to GND during startup 50 µA

MAX8902A/MAX8902B

Low-Noise 500mA LDO Regulators

in a 2mm x 2mm TDFN Package

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VIN= VEN= 5V, OUTS = OUT, circuit of Figure 2 (MAX8902A) and Figure 3 (MAX8902B), TA= -40°C to +125°C, unless otherwise
noted.) (Note 1)

PARAMETER CONDITIONS MIN TYP MAX UNITS

GND

TA < +85°C 80 120

GND Supply Current I

OUT

= 0mA

T

A

< +125°C 160

µA

TA = +25°C 0.001 +1

GND Shutdown Current VIN = 5.5V, EN = 0V

T

A

= +85°C 0.01

µA

SELA/SELB (MAX8902A only)

When shorted to GND or V

IN

500 Ω

Select Input Resistance

When open 1 MΩ

Select Input Capacitance When open 10 pF

EN

EN rising 0.8 1.2

EN falling, TA < +85°C 0.4 0.7Enable Input Threshold VIN = 1.7V to 5.5V

EN falling, T

A

< +125°C 0.38 0.7

V

TA = +25°C -1 0.001 +1

Enable Input Bias Current VEN = 0V to 5.5V

T

A

= +85°C 0.01

µA

POK (MAX8902B only)

OUT rising 88 91 94 %

POK Threshold

OUT voltage when POK
switches

OUT falling 88 %

POK Voltage, Low I

POK

= 1mA 10 100 mV

TA = +25°C -1 0.001 +1

POK Leakage Current POK = 5.5V, VEN = 0V

T

A

= +85°C 0.01

µA

THERMAL SHUTDOWN

TJ rising 165

Thermal Shutdown Threshold

T

J

falling 150

°C

OUTPUT TRANSIENT

Load Transient I

OUT

= 50mA to 500mA to 50mA, t

RISE

= t

FALL

= 1µs 25

mV/

P-P

Line Transient VIN = 4V to 5V to 4V, t

RISE

= t

FALL

= 5µs, I

OUT

= 500mA 3

mV/

P-P

IN-to-OUT Reverse Voltage
Turnoff Threshold

IN falling below OUT 10 mV

Note 1: All devices are production tested at TA= +25°C. Specifications over the operating temperature range are guaranteed by

design and characterization.

Note 2: The dropout voltage is defined V

IN

- V

OUT

, when V

OUT

is 5% lower than the value of V

OUT

when VIN= V

OUT

+ 0.5V.

MAX8902A/MAX8902B

Low-Noise 500mA LDO Regulators
in a 2mm x 2mm TDFN Package

4 _______________________________________________________________________________________

Typical Operating Characteristics

(MAX8902A, VIN= 3.6V, V

OUT

= 2.5V, TA= +25°C, unless otherwise noted.)

0

40

20

80

60

120

100

140

023145

QUIESCENT CURRENT

EN = HIGH, NO LOAD

MAX8902A/02B toc01

INPUT VOLTAGE (V)

INPUT CURRENT (μA)

2.500

2.502

2.501

2.504

2.503

2.505

2.506

0200100 300 400 500

LOAD REGULATION

MAX8902A/02B toc02

LOAD CURRENT (mA)

OUTPUT VOLTAGE (V)

3.6V INPUT

2.490

2.496

2.494

2.492

2.498

2.500

2.502

2.504

2.506

2.508

2.510

1.5 2.5 3.5 4.5 5.5

LINE REGULATION

MAX8902A/02B toc03

INPUT VOLTAGE (V)

OUTPUT VOLTAGE (V)

200mA LOAD

40ms/div

LOAD TRANSIENT RESPONSE

50mA TO 500mA TO 50mA

V

OUT

100mV/div

200mA/div

MAX8902A/02B toc04

I

OUT

t

RISE

= t

FALL

= 1μs

10μs/div

LOAD TRANSIENT RESPONSE

V

IN

2V/div

2mV/div

MAX8902A/02B toc05

V

OUT

2.5V OUTPUT
5Ω LOAD

5V

4V

5V

100μs/div

STARTUP WAVEFORM

V

EN

500mV/div

2V/div

200mA/div

MAX8902A/02B toc06

I

IN

V

OUT

5Ω LOAD
C

BYP

= 0.01μF

0

10

20

30

40

50

60

70

80

0 100 200 300 400 500

DROPOUT VOLTAGE vs. LOAD CURRENT

MAX8902A/02B toc07

LOAD CURRENT (mA)

DROPOUT VOLTAGE (mV)

3.6V INPUT, 4.6V OUTPUT PRESET
THE SLOPE OF THE LINE INDICATES
A 129mΩ ON-RESISTANCE IN
DROPOUT

PSRR vs. FREQUENCY

MAX8902A/02B toc08

10k1k10010 100k

FREQUENCY (Hz)

0

-10

-20

-30

-40

-50

-60

-70

-80

-90

-100

PSRR (dB)

MAX8902A LDO OUTPUT-NOISE SPECTRAL

DENSITY vs. FREQUENCY

MAX8902A/02B toc09

FREQUENCY (Hz)

100k10k1k100

100E+0

1E+3

10E+3

10E+0

10 1M

NOISE DENSITY (nV √Hz)