Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsLinear ICsLinear IC - Op-amp Current sensor uMAX 8

General Description

The MAX9928/MAX9929 low-cost, uni-/bidirectional,

high-side, current-sense amplifiers are ideal for monitor-

ing battery charge and discharge currents in notebooks,

cell phones, and other portable equipment. These devices

feature a wide -0.1V to +28V input common-mode voltage

range, low 20μA supply current with V

less than 0.4mV,

and a gain accuracy better than 1.0%. The input common-

mode range is independent of the supply voltage, ensur-

ing that the current-sense information remains accurate

even when the measurement rail is shorted to ground.

The MAX9928F features a current output with a transcon-

ductance ratio of 5μA/mV. An external resistor converts

the output current to a voltage, allowing adjustable gain

so that the input sense voltage can be matched to the

maximum ADC input swing. The MAX9929F has a volt-

age output and integrates a 10kΩ output resistor for a

fixed voltage gain of 50V/V.

A digital SIGN output indicates direction of current flow, so

the user can utilize the full ADC input range for measuring

both charging and discharging currents.

The MAX9928/MAX9929 are fully specified over the

-40°C to +125°C automotive temperature range, and

available in 6-bump UCSP™ (1mm x 1.5mm) and 8-pin

μMAX

packages. The UCSP package is bump-to-bump

compatible with the MAX4372_EBT.

Features

● Wide -0.1V to +28V Common-Mode Range,

Independent of Supply Voltage

● 2.5V to 5.5V Operating Supply Voltage

● 20μA Quiescent Supply Current

● 0.4mV (max) Input Offset Voltage

● Gain Accuracy Better than 1% (max)

● SIGN Output Indicates Current Polarity

● Transconductance and Gain Versions Available

• 5μA/mV (MAX9928F)

• 50V/V (MAX9929F)

● Pin Compatible with the MAX4372 in UCSP

● Available in Ultra-Small, 3x2 UCSP

(1mm x 1.5mm) and 8-Pin μMAX Packages

Applications

● Monitoring Charge/Discharge Currents in Portable/

Battery-Powered Systems

● Notebook Computers

● General-System/Board-Level Current Monitoring

● Smart-Battery Packs/Chargers

● Precision Current Sources

● Smart Cell Phones

● Super Capacitor Charge/Discharge

Pin Configurations and Typical Operating Circuit appear at

end of data sheet.

UCSP is a trademark and μMAX is a registered trademark of

Maxim Integrated Products, Inc.

19-4251; Rev 4; 9/14

Note: All devices are specified over the -40°C to +125°C operating temperature range.

+Denotes a lead(Pb)-free/RoHS-compliant package.

T = Tape and reel.

PART OUTPUT TYPE GAIN PIN-PACKAGE TOP MARK

MAX9928FAUA+ Current G

= 5μA/mV 8 μMAX —

MAX9928FABT+T Current G

= 5μA/mV 3x2 UCSP +AAF

MAX9929FAUA+ Voltage A

= 50V/V 8 μMAX —

MAX9929FABT+T Voltage A

= 50V/V 3x2 UCSP +ADI

MAX9928/MAX9929 -0.1V to +28V Input Range, Micropower,

Uni-/Bidirectional, Current-Sense Amplifiers

Ordering Information

EVALUATION KIT AVAILABLE

Summary of content (13 pages)

PAGE 1
EVALUATION KIT AVAILABLE MAX9928/MAX9929 -0.1V to +28V Input Range, Micropower, Uni-/Bidirectional, Current-Sense Amplifiers General Description The MAX9928/MAX9929 low-cost, uni-/bidirectional, high-side, current-sense amplifiers are ideal for monitoring battery charge and discharge currents in notebooks, cell phones, and other portable equipment. These devices feature a wide -0.1V to +28V input common-mode voltage range, low 20μA supply current with VOS less than 0.
PAGE 2
MAX9928/MAX9929 -0.1V to +28V Input Range, Micropower, Uni-/Bidirectional, Current-Sense Amplifiers Absolute Maximum Ratings VCC, SIGN to GND..................................................-0.3V to +6V RS+, RS- to GND...................................................-0.3V to +30V OUT to GND.............................................. -0.3V to (VCC + 0.3V) Differential Input Voltage (VRS+ - VRS-)...............................±30V OUT, SIGN Short Circuit to VCC or GND...................
PAGE 3
MAX9928/MAX9929 -0.1V to +28V Input Range, Micropower, Uni-/Bidirectional, Current-Sense Amplifiers Electrical Characteristics (continued) (VRS+ = -0.1V to +28V, VCC = 3.3V, VSENSE = (VRS+ - VRS-) = 0V, ROUT = 10kΩ for MAX9928F, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Output Resistance Output High Voltage (Note 6) SYMBOL ROUT VOH CONDITIONS MIN MAX9928F 6.
PAGE 4
MAX9928/MAX9929 -0.1V to +28V Input Range, Micropower, Uni-/Bidirectional, Current-Sense Amplifiers Electrical Characteristics (continued) (VRS+ = -0.1V to +28V, VCC = 3.3V, VSENSE = (VRS+ - VRS-) = 0V, ROUT = 10kΩ for MAX9928F, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS AC ELECTRICAL CHARACTERISTICS -3dB Bandwidth OUT Settling to 1% of Final Value BW MAX992_F, VSENSE = 50mV tSET VRS+ = 3.
PAGE 5
MAX9928/MAX9929 -0.1V to +28V Input Range, Micropower, Uni-/Bidirectional, Current-Sense Amplifiers Typical Operating Characteristics (VCC = 3.3V, VRS+ = 12V, TA = +25°C, unless otherwise noted.) 25 20 15 20 15 10 10 5 5 0.6 0.4 0.2 0 -0.2 -0.4 150 VRS+ = 0V 75 50 0 -40 -25 -10 5 20 35 50 65 80 95 110 125 VRS+ = 3.6V 2.5 TEMPERATURE (°C) 3.0 3.5 4.0 4.5 MAX9928 toc03 3 28 90 VCC = 5.5V 60 VCC = 2.5V 5.0 0 5.5 -0.5 0 0.5 1.0 1.5 2.
PAGE 6
MAX9928/MAX9929 -0.1V to +28V Input Range, Micropower, Uni-/Bidirectional, Current-Sense Amplifiers Typical Operating Characteristics (continued) (VCC = 3.3V, VRS+ = 12V, TA = +25°C, unless otherwise noted.) VOUT (V) TA = +125°C 1000 1 0.1 0.2 0.3 0.4 20 40 60 80 100 120 GAIN ACCURACY vs. SUPPLY VOLTAGE MINIMUM OUTPUT VOLTAGE vs. TEMPERATURE MAX9928 toc12 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 2.6 2.0 140 5.0 1.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 5.5 -0.4 -0.6 1.
PAGE 7
MAX9928/MAX9929 -0.1V to +28V Input Range, Micropower, Uni-/Bidirectional, Current-Sense Amplifiers Typical Operating Characteristics (continued) (VCC = 3.3V, VRS+ = 12V, TA = +25°C, unless otherwise noted.) MAX9929F LARGE-SIGNAL TRANSIENT RESPONSE PSRR vs. FREQUENCY MAX9928 toc18 MAX9928 toc17 20 0 PSRR (dB) -20 VSENSE 50mV/div -40 -60 -80 VOUT 1V/div -100 -120 0.1 1 10 100 1k 10k 100k 100µs/div FREQUENCY (Hz) VSIGN AND VOUT vs.
PAGE 8
MAX9928/MAX9929 -0.1V to +28V Input Range, Micropower, Uni-/Bidirectional, Current-Sense Amplifiers Pin Configuration PIN BUMP µMAX UCSP 1 B3 RS- 2 B2 SIGN SIGN Output. Indicates polarity of VSENSE. SIGN = H indicates VRS+ > VRSSIGN = L indicates VRS+ < VRS- 3 B1 RS+ Positive Current-Sense Input. Power-side connection to the external sense resistor. 4, 5 — N.C. No Connection. Not internally connected. 6 A1 VCC Supply Voltage Input. Bypass to GND with a 0.1µF capacitor.
PAGE 9
MAX9928/MAX9929 2.5V TO 5.5V -0.1V to +28V Input Range, Micropower, Uni-/Bidirectional, Current-Sense Amplifiers VCC RC1 80kΩ VCC MAX9928F MAX9929F 1MΩ SIGN C RC2 80kΩ TO C CURRENT MIRROR VIN -0.1V TO +28V (VBATT) VSENSE RSENSE + - S2 RG1 80kΩ RS+ RG2 80kΩ RS- A TO LOAD/CHARGER S1 Q1 OUT Q2 TO ADC 10kΩ* GND *INTERNAL 10kΩ RESISTOR FOR MAX9929_ ONLY. Figure 1.
PAGE 10
MAX9928/MAX9929 -0.1V to +28V Input Range, Micropower, Uni-/Bidirectional, Current-Sense Amplifiers Voltage Output (MAX9929F) The output voltage equation for the MAX9929_ is given below: VOUT = (RSENSE x ILOAD) x (AV) where VOUT = the desired full-scale output voltage, ILOAD = the full-scale current being sensed, RSENSE = the current-sense resistor, AV = MAX9929F voltage gain (50V/V). SIGN Output The current/voltage at OUT indicates magnitude. The SIGN output indicates the current’s direction.
PAGE 11
MAX9928/MAX9929 -0.1V to +28V Input Range, Micropower, Uni-/Bidirectional, Current-Sense Amplifiers Pin Configurations TOP VIEW (BUMPS ON THE BOTTOM) TOP VIEW RS- 1 SIGN 2 RS+ 3 N.C. 4 + MAX9928F MAX9929F 8 OUT 7 GND 6 VCC 5 N.C. µMAX A 1 2 3 VCC GND OUT MAX9928F MAX9929F B RS+ SIGN RS- UCSP (1mm x 1.5mm) Typical Operating Circuit VIN -0.1V TO +28V 2.5V TO 5.5V 0.
PAGE 12
MAX9928/MAX9929 -0.1V to +28V Input Range, Micropower, Uni-/Bidirectional, Current-Sense Amplifiers Package Information 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. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.
PAGE 13
MAX9928/MAX9929 -0.1V to +28V Input Range, Micropower, Uni-/Bidirectional, Current-Sense Amplifiers Revision History REVISION NUMBER REVISION DATE 0 12/08 Initial release 1 8/09 Removed MAX9928T and MAX9929T from data sheet 2 4/11 Updated top marks 1 3 4/12 Removed the R61A1+1 package code note and references 1 4 9/14 Removed automotive reference from data sheet.