Datasheet

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General Description

The MAX44284 is a high-side, current-sense amplifier

that operates with a 1.7V to 5.5V single supply and is

optimized for very low power operation with only 21µA of

quiescent current.

The MAX44284 offers precision accuracy specifications

of 2μV V

and gain error of 0.05%. The device features

an input common-mode voltage range from -0.1V to

+36V. This current-sense amplifier has a voltage output

and is offered in four different gain versions.

The MAX44284 is offered in small 6-bump, 0.4mm-pitch

WLP (1.3mm x 0.9mm) and 6-pin SOT23 packages and is

specified for operation over the -40°C to +125°C automo-

tive temperature range.

Applications

● Smartphones and Tablets

● Notebook Computers

● DC-DC Current Sensing in Power Management

● Portable-/Battery-Powered Systems

● Medical Pulse Oximeters and Infusion Pumps

● Base-Stations

Benets and Features

● Very Low 2μV Input Offset Voltage (MAX44284F/H))

● Extremely Low 50nV/°C Input Offset Temperature

Coefficient

● Low Supply Current of 21μA

● Low 0.05% Gain Error

● -0.1V to +36V Wide Input Common-Mode Range

● Shutdown Input (Independent of V

)

● Four Gain Options:

• 50V/V – MAX44284F

• 100V/V – MAX44284H

• 200V/V – MAX44284W

• 500V/V – MAX44284E

● Tiny 1.3mm x 0.9mm 6-Bump WLP Package and

6-Pin SOT23 Package

Ordering Information appears at end of data sheet.

For related parts and recommended products to use with this part, refer

to www.maximintegrated.com/MAX44284.related.

SENSE

BATT

= UP TO 36V

RS+ RS-

ADC

µC

= 3.3V

OUT

= 3.3V

LOAD

MAX44284

LOAD

MAX44284 36V, Input Common-Mode, High-Precision,

Low-Power Current-Sense Amplifier

19-6862; Rev 3; 9/14

Typical Application Circuit

Summary of content (14 pages)

PAGE 1
MAX44284 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier General Description The MAX44284 is a high-side, current-sense amplifier that operates with a 1.7V to 5.5V single supply and is optimized for very low power operation with only 21µA of quiescent current. The MAX44284 offers precision accuracy specifications of 2μV VOS and gain error of 0.05%. The device features an input common-mode voltage range from -0.1V to +36V.
PAGE 2
MAX44284 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier Absolute Maximum Ratings VDD to GND.............................................................-0.3V to +6V RS+, RS- to GND...................................................-0.3V to +40V RS+ to RS-...........................................................................±40V OUT, SHDN to GND.................................. -0.3V to (VDD + 0.3V) Continuous Input Current (any pin)...................................
PAGE 3
MAX44284 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier Electrical Characteristics (continued) (VDD = 3.3V, VCM = 12V, VSENSE = VFS/2, VFS = (VDD - VOH - VOL)/Gain, VSHDN = VDD, RL = 10kΩ to GND, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 4
MAX44284 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier Electrical Characteristics (continued) (VDD = 3.3V, VCM = 12V, VSENSE = VFS/2, VFS = (VDD - VOH - VOL)/Gain, VSHDN = VDD, RL = 10kΩ to GND, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 5
MAX44284 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. TEMPERATURE 27 VDD = 3.3V VDD = 5.5V 25 23 21 17 -50 -25 0 25 50 VDD = 3.3V 28 26 24 75 100 20 125 32 -50 0 25 50 75 TEMPERATURE (°C) 29 28 VDD = 3.3V 26 25 -25 0 25 50 75 100 16 HISTOGRAM 8 6 4 -0.08 -0.06 -0.04 -0.02 0 0.02 0.04 0.06 0.08 GAIN ERROR (%) www.maximintegrated.
PAGE 6
MAX44284 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) ALL GAIN OPTIONS 7 6 5 4 3 2 1 0 GAIN = 50V/V 0.6 SUPPLY CURRENT (µA) OCCURRENCE N (%) 0.7 VDD = 5.5V 700 0.5 600 0.4 VDD = 3.3V 0.3 500 400 300 VDD = 1.7V 0.2 0 VDD = 3.3V 800 200 0.1 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 INPUT OFFSET VOLTAGE DRIFT (nV/°C) VOH vs.
PAGE 7
MAX44284 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) 0.045 0.040 0.035 0.030 0.025 0.020 0.04 GAIN = 100V/V 0.02 -0.02 0.010 0.005 -0.04 1.7 2.1 2.5 2.8 3.2 3.6 4.0 4.4 4.7 5.1 5.5 VDD (V) 120 VCM = -0.1V to +36V 110 50 75 100 125 POWER-SUPPLY REJECTION RATIO vs. TEMPERATURE 120 110 100 90 100 80 90 -50 -25 0 25 50 75 TEMPERATURE (ºC) 70 125 100 INPUT BIAS CURRENT vs.
PAGE 8
MAX44284 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) MAGNITUDE (dB) G = 200V/V 50 40 30 G = 100V/V 20 G = 50V/V 10 0 -10 -20 100 10 0 10 100 1k 10k INPUT-VOLTAGE NOISE vs. FREQUENCY MAX44284 toc18 G = 500V/V 60 1000 INPUT VOLTAGE NOISE (nV√Hz) 70 MAX44284 toc17 GAIN vs. FREQUENCY 80 100k 0.
PAGE 9
MAX44284 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier Pin Configurations TOP VIEW TOP VIEW VDD 1 + 6 SHDN VDD OUT A1 A2 A3 B1 B2 B3 + MAX44284 MAX44284 RS+ GND 2 5 OUT RS+ 3 4 RS- RS- SOT23 GND SHDN WLP Pin Description PIN BUMP SOT23 WLP 1 A2 VDD Power-Supply Voltage Input. Bypass VDD to GND with 0.1μF and 4.7μF capacitors in parallel as close as possible to the device.
PAGE 10
MAX44284 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier Detailed Description The MAX44284 family features a single-supply; highaccuracy unidirectional, current-sense amplifier in various gain options and a -0.1V to 36V input common-mode range that is independent of supply voltage (VDD). The MAX44284 is ideal for many battery-powered, handheld devices because it uses only maximum 31.2μA quiescent supply current to extend battery life.
PAGE 11
MAX44284 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier A high RSENSE value allows lower currents to be measured more accurately because offsets are less significant when the sense voltage is larger. Note that the tolerance and temperature coefficient of the chosen resistors directly affect the precision of any measurement system. For best performance, select RSENSE to provide approximately maximum input differential sense voltage of 110mV (MAX44284F) or 55mV (MAX44284H) or 27.
PAGE 12
MAX44284 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier Output Filtering For gain error, it depends on its input impedance and RIN. The internal architecture of the MAX44284 suppresses the DC offset, 1/f noise, and accumulates at higher frequencies so that they can be filtered out. Hence, minute AC disturbances can be observed at 10kHz and 20kHz.
PAGE 13
MAX44284 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier Ordering Information PART GAIN (V/V) TEMP RANGE PIN-PACKAGE TOP MARK MAX44284FAWT+ 50 -40°C to +125°C 6 WLP +CX MAX44284FAUT+ 50 -40°C to +125°C 6 SOT23 +ACSF MAX44284HAWT+ 100 -40°C to +125°C 6 WLP +CY MAX44284HAUT+ 100 -40°C to +125°C 6 SOT23 +ACSG MAX44284WAWT+ 200 -40°C to +125°C 6 WLP +CZ MAX44284WAUT+ 200 -40°C to +125°C 6 SOT23 +ACSH MAX44284EAWT+ 500 -40°C to +125°C 6 WLP +DA
PAGE 14
MAX44284 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier Revision History REVISION NUMBER REVISION DATE PAGES CHANGED 0 12/13 Initial release 1 5/14 Updated Typical Operating Characteristics and the Ordering Information 8, 13 2 6/14 Corrected General Description and updated Electrical Characteristics globals 1–4 3 9/14 Released MAX44284E and updated the Electrical Characteristics 3, 13 DESCRIPTION — For pricing, delivery, and ordering information, please conta