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 monitoring 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 features fixed gains of 45V/V (MAX9919F) and 90V/V
(MAX9919N). The MAX9918/MAX9919/MAX9920 operate as unidirectional amplifiers when VREFIN = GND and as bidirectional amplifiers when VREFIN = VCC/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 single 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.
Key Features
Applications/Uses
-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
4x4 Transmission Control
Current Monitoring of Inductive Loads
Electronic Throttle Control
H-Bridge Motor Current Sensing
High- and Low-Side Precision Current Sensing
Precision High-Voltage Current Monitoring
Solenoid Current Sensing
Super-Capacitor Charge/Discharge Monitoring in Hybrid Cars