MAX9922 Datasheet, PDF (1/14 Pages) Maxim Integrated Products – Ultra-Precision, High-Side Current-Sense Amplifiers

19-4429; Rev 0; 3/09
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Ultra-Precision, High-Side
Current-Sense Amplifiers
General Description
The MAX9922/MAX9923 ultra-precision, high-side cur-
rent-sense amplifiers feature ultra-low offset voltage
(V_OS) of 25µV (max) and laser-trimmed gain accuracy
better than 0.5%. The combination of low V_OS and high-
gain accuracy allows precise current measurements
even at very small sense voltages.
The MAX9922/MAX9923 are capable of both unidirec-
tional and bidirectional operation. For unidirectional
operation, connect REF to GND. For bidirectional oper-
ation, connect REF to V_DD/2.
The MAX9922 has adjustable gain set with two external
resistors. The MAX9923T/MAX9923H/MAX9923F use an
internal laser-trimmed resistor for fixed gain of 25V/V,
100V/V, and 250V/V, respectively. The devices operate
from a +2.85V to +5.5V single supply, independent
of the input common-mode voltage, and draw only 700µA
operating supply current and less than 1µA in shutdown.
The +1.9V to +28V current-sense input common-mode
voltage range makes the MAX9922/MAX9923 ideal for
current monitoring in applications where high accuracy,
large common-mode measurement range, and mini-
mum full-scale V_SENSE voltage is critical.
The MAX9922/MAX9923 use a patented spread-spec-
trum autozeroing technique that constantly measures
and cancels the input offset voltage, eliminating drift
over time and temperature, and the effect of 1/f noise.
This, in conjunction with the indirect current-feedback
technique, achieves less than 25µV (max) offset voltage.
The MAX9922/MAX9923 are available in a small 10-pin
µMAX^® package and are specified over the -40°C to
+85°C extended temperature range.
Applications
Notebook/Desktop Power Management
Handheld Li+ Battery Current Monitoring
Precision Current Sources
Typical Operating Circuits appear at end of data sheet.
µMAX is a registered trademark of Maxim Integrated Products, Inc.
Features
♦ Ultra-Precision V_OS Over Temperature
MAX9922: ±10µV (max)
MAX9923T: ±25µV (max)
MAX9923H: ±20µV (max)
MAX9923F: ±10µV (max)
♦ ±0.5% (max) Full-Scale Gain Accuracy
♦ Bidirectional or Unidirectional I_SENSE
♦ Multiple Gains Available
Adjustable (MAX9922)
+25V/V (MAX9923T)
+100V/V (MAX9923H)
+250V/V (MAX9923F)
♦ 1.9V to 28V Input Common-Mode Voltage,
Independent of V_DD
♦ Supply Voltage: +2.85V to +5.5V
♦ 700µA Supply Current, 1µA Shutdown Current
♦ Extended Temperature Range (-40°C to +85°C)
♦ Available in Space-Saving 10-Pin µMAX
Ordering Information
PART
MAX9922EUB+
PIN-
PACKAGE
10 µMAX
TEMP
RANGE
-40°C to +85°C
GAIN (V/V)
Adjustable
MAX9923TEUB+ 10 µMAX -40°C to +85°C
25
MAX9923HEUB+ 10 µMAX -40°C to +85°C
100
MAX9923FEUB+ 10 µMAX -40°C to +85°C
250
+Denotes a lead(Pb)-free/RoHS-compliant package.
Pin Configuration
TOP VIEW
RSB 1 ⁺
RS+ 2
RS- 3
N.C. 4
GND 5
MAX9922
MAX9923T
MAX9923H
MAX9923F
10 V_DD
9 OUT
8 FB
7 REF
6 SHDN
µMAX
________________________________________________________________ Maxim Integrated Products 1
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.