Rainbow Electronics MAX9610 - Manual (Page 7)

MAX9610
1µA, µDFN/SC70, Lithium-Ion Battery,
Precision Current-Sense Amplifier
_______________________________________________________________________________________ 7
Kelvin Connections
Because of the high currents that flow through R SENSE ,
take care to eliminate parasitic trace resistance from
causing errors in the sense voltage. Either use a four
terminal current-sense resistor or use Kelvin (force and
sense) PCB layout techniques.
Optional Output Filter Capacitor
When designing a system that uses a sample and hold
stage in the analog-to-digital converter, the sampling
capacitor momentarily loads OUT and causes a drop in
the output voltage. If sampling time is very short (less
than a microsecond), consider using a ceramic capaci-
tor across OUT and GND to hold V
OUT constant during
sampling. This also decreases the small-signal band-
width of the current-sense amplifier and reduces noise
at OUT.
Typical Application Circuit
Bidirectional Application
Battery-powered systems may require a precise bidi-
rectional current-sense amplifier to accurately monitor
the battery’s charge and discharge currents.
Measurements of the two separate outputs with respect
to GND yield an accurate measure of the charge and
discharge currents, respectively (Figure 1).
MAX9610
P
R OUT
GND
OUT OUT
ADC
ADC
LOAD
RS- RS+
R SENSE
I LOAD
V
BATT
= 1.6V TO 5.5V
MAX9610
P
R OUT
GND
RS- RS+
R
1
R
1 R 1 R 1
MICRO-
CONTROLLER
V DD = 3.3V
TO WALL-CUBE/
CHARGER
Figure 1. Bidirectional Application