MAX9918_10 Datasheet, PDF (1/18 Pages) Maxim Integrated Products – -20V to +75V Input Range, Precision Uni-/Bidirectional, Current-Sense Amplifiers

19-5015; Rev 2; 12/10
EVAALVUAAILTAIOBNLEKIT
-20V to +75V Input Range, Precision
Uni-/Bidirectional, Current-Sense Amplifiers
General 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. These amplifiers are well suited for current moni-
toring of inductive loads such as motors and solenoids,
where common-mode voltages can become negative
due to inductive kickback, reverse-battery conditions,
or transient events.
The MAX9918/MAX9920 feature adjustable gain set by
an external resistive-divider network. The MAX9919 fea-
tures fixed gains of 45V/V (MAX9919F) and 90V/V
(MAX9919N). The MAX9918/MAX9919/MAX9920 oper-
ate as unidirectional amplifiers when V_REFIN = GND
and as bidirectional amplifiers when V_REFIN = V_CC/2.
The MAX9920 attenuates the input signal by a factor of
4 at the input level-shifting stage allowing the device to
sense voltages up to 200mV (unidirectional operation)
or ±100mV (bidirectional operation).
The MAX9918/MAX9919/MAX9920 operate with a sin-
gle 5V supply voltage, are fully specified over the -40°C
to +125°C automotive temperature range, and are
available in an 8-pin SOIC package.
Applications
H-Bridge Motor Current Sensing
Solenoid Current Sensing
Current Monitoring of Inductive Loads
High- and Low-Side Precision Current Sensing
4x4 Transmission Control
Electronic Throttle Control
Super-Capacitor Charge/Discharge Monitoring in
Hybrid Cars
Precision High-Voltage Current Monitoring
Features
♦ -20V to +75V Input Common-Mode Voltage Range
♦ 400µV (max) Input Offset Voltage
♦ 0.6% (max) Gain Accuracy Error
♦ Uni- or Bidirectional Current Sensing
♦ Reference Input for Bidirectional OUT
♦ 120kHz, -3dB Bandwidth (MAX9919N)
♦ Single-Supply Operation (4.5V to 5.5V)
♦ 1mA Supply Current
♦ 0.5µA (typ) Shutdown Current
♦ Rail-to-Rail Output
♦ -40°C to +125°C Automotive Temperature Range
Ordering Information/
Selector Guide
PART
V_SENSE
(mV)
GAIN
(V/V)
PIN-PACKAGE
MAX9918ASA+
±50 Adjustable 8 SOIC-EP*
MAX9918ASA/V+ ±50 Adjustable 8 SOIC-EP*
MAX9919FASA+ ±50
45
8 SOIC-EP*
MAX9919NASA+ ±50
90
8 SOIC-EP*
MAX9920ASA+
±200 Adjustable 8 SOIC-EP*
Note: All devices operate over the -40°C to +125°C temperature
range.
+Denotes a lead(Pb)-free/RoHS-compliant package.
/V denotes an automotive qualified part.
*EP = Exposed pad.
Typical Operating Circuit
V_BATT
V_CC
V_CC
φ1A
R_SENSE
φ2B
MAX9918
MAX9920
M
RS+
A
OUT
ADC
R2
FB
INPUT STAGE
RS-
LEVEL SHIFTER
REFIN
R1
REF
φ2B
φ1B
ADJUSTABLE GAIN
μC
SHDN
GND
GND
________________________________________________________________ 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.