MAX9934 Datasheet, PDF (1/22 Pages) Maxim Integrated Products – High-Precision, Low-Voltage, Current-Sense Amplifier with Current Output and Chip Select for Multiplexing

19-5011; Rev 0; 10/09
EVAALVUAAILTAIOBNLEKIT
High-Precision, Low-Voltage, Current-Sense Amplifier
with Current Output and Chip Select for Multiplexing
General Description
The MAX9934** high-precision, low-voltage, high-side
current-sense amplifier is ideal for both bidirectional
(charge/discharge) and unidirectional current measure-
ments in battery-powered portable and laptop devices.
Input offset voltage (V_OS) is a low 10µV (max) at +25°C
across the -0.1V to 5.5V input common-mode voltage
range, and is independent of V_CC. Its precision input
specification allows the use of very small sense volt-
ages (typically ±10mV full-scale) for minimally invasive
current sensing.
The output of the MAX9934 is a current proportional to
input V_SENSE and is available in either 25µA/mV or
5µA/mV gain options (G_M) with gain accuracy better
than 0.25% (max) at +25°C. A chip select (CS) allows
multiplexing of several MAX9934 current outputs to a
single microcontroller ADC channel (see the Typical
Operating Circuit). CS is compatible with 1.8V and 3.3V
logic systems.
The MAX9934 is designed to operate from a 2.5V to
3.6V V_CC supply, and draws just 120µA (typ) quiescent
current. When powered down (V_CC = 0), RS+ and RS-
draw less than 0.1nA (typ) leakage current to reduce
battery load. The MAX9934 is robust and protected
from input faults of up to ±6V input differential voltage
between RS+ and RS-.
The MAX9934 is specified for operation over the -40°C
to +125°C temperature range and is available in 8-pin
µMAX^®, 6-pin µDFN (2mm x 2mm x 0.8mm), or a 6-
bump UCSP™ (1mm x 1.5mm x 0.6mm), making it ideal
for space-sensitive applications.
Applications
PDAs and Smartphones
MP3 Players
Sensor Instrumentation Amplifiers
Notebook PCs and Ultra-Mobile PCs
Portable Current Monitoring
Features
o Input Offset Voltage: 10µV (max)
o Gain Error Less than 0.25%
o -0.1V to +5.5V Input Common-Mode Voltage
Range
o Chip Select Allows Multiplexing Several MAX9934
Current Monitors to One ADC
o Current Output Allows R_OUT Selection
for Gain Flexibility
o Single Supply Operation: 2.5V to 3.6V
o Two Gain Options: G_M of 25µA/mV (MAX9934T)
and 5µA/mV (MAX9934F)
o Bidirectional or Unidirectional Operation
o Small, 6-Bump UCSP (1mm x 1.5mm x 0.6mm),
6-Pin µDFN (2mm x 2mm x 0.6mm), and 8-Pin
µMAX Packages
Ordering Information
PART
GAIN
PIN-
PACKAGE
TOP
MARK
MAX9934FALT+T*
5µA/mV 6 µDFN
ACP
MAX9934FART+T*
5µA/mV 6 UCSP
AAG
MAX9934FAUA+T
5µA/mV 8 µMAX
—
MAX9934TALT+T*
25µA/mV 6 µDFN
ACO
MAX9934TART+T* 25µA/mV 6 UCSP
AAF
MAX9934TAUA+T
25µA/mV 8 µMAX
—
Note: All devices are specified over the -40°C to +125°C
extended temperature range.
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
*Future product—contact factory for availability.
Typical Operating Circuit
ILOAD
-0.1V ≤ VCM ≤ 5.5V
RSENSE
VCC = 3.3V
0.1µF
VCC
MAX9934
RS-
OUT
VOUT TO ADC
µMAX is a registered trademark and UCSP is a trademark of
Maxim Integrated Products, Inc.
**Patent pending.
RS+
GND
ROUT
10kΩ
CS
FROM µC
CHIP SELECT
1000pF
________________________________________________________________ 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.