MAX9920 Maxim, MAX9920 Datasheet - Page 13

• Manufacturer Part Number: MAX9920
• Description: The MAX9918/MAX9919/MAX9920 are single-supply, high-accuracy current-sense amplifiers with a high input common-mode range that extends from -20V to +75V
• Manufacturer: Maxim

The MAX9918/MAX9919/MAX9920 are single-supply,
high-accuracy uni-/bidirectional current-sense amplifiers
with a high common-mode input range that extends from
-20V to +75V. The MAX9918/MAX9919/MAX9920’s input
stage utilizes a pair of level shifters allowing a wide
common-mode operating range when measuring the
voltage drop (V
The first level shifter accommodates the upper common-
mode operating range from +2V to +75V. When the
common-mode voltage falls below +2V, the second level
shifter is used to accommodate negative voltages down
to -20V.
PIN
—
1
2
3
4
5
6
7
8
Uni-/Bidirectional, Current-Sense Amplifiers
SENSE
NAME
SHDN
REFIN
GND
OUT
RS+
V
RS-
FB
EP
CC
______________________________________________________________________________________
) across the current-sense resistor.
Detailed Description
Positive Current-Sensing Input. Power side connects to external sense resistor.
Negative Current-Sensing Input. Load side connects to external sense resistor.
Active-High Shutdown Input. Connect to GND for normal operation.
Ground
Current-Sense Output. V
Feedback Input. Connect FB to a resistive-divider network to set the gain for the MAX9918 and
MAX9920. See the Adjustable Gain (MAX9918/MAX9920) section for more information. Leave FB
unconnected for the MAX9919 for proper operation.
Reference Input. Set REFIN to V
operation.
5V Supply Voltage Input. Bypass V
Exposed Pad. Connect to a large-area contiguous ground plane for improved power dissipation. Do
not use as the only ground connection for the part.
-20V to +75V Input Range, Precision
TOP VIEW
*EXPOSED PAD. CONNECT EP TO SOLID GROUND FOR
PROPER THERMAL AND ELECTRICAL PERFORMANCE.
SHDN
GND
RS+
RS-
OUT
1
2
4
3
+
is proportional to V
8 SOIC-EP
CC
MAX9918
MAX9919
MAX9920
/2 for bidirectional operation. Set REFIN to GND for unidirectional
CC
to GND with 0.1μF capacitor.
EP*
The level shifters translate V
ence voltage where it is then amplified with an instru-
mentation amplifier. The instrumentation amplifier
configuration provides high precision with input offset
voltages of 400μV (max). Indirect feedback of the
instrumentation amplifier allows the gain to be adjusted
with an external resistive-divider network on the
MAX9918/MAX9920. The MAX9919 is a fixed gain
device available with laser-trimmed resistors for gains
of 45V/V (MAX9919F) and 90V/V (MAX9919N).
The MAX9918/MAX9919 operate with a full-scale sense
voltage of 50mV. The input stage of the MAX9920 pro-
vides an attenuation factor of 4, enabling a full-scale
sense voltage of 200mV.
8
7
6
5
FUNCTION
V
REFIN
FB
OUT
CC
SENSE
.
Pin Configuration
SENSE
Pin Description
to an internal refer-
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