Maxim’s MAX9918-20 family are current-sense amplifiers which offer single-supply and high accuracy with a high input common-mode range that extends from -20 V to +75 V. This family is 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 and MAX9920 feature adjustable gain set by an external resistive-divider network. The MAX9919 features fixed gains of 45 V/V (MAX9919F) and 90 V/V (MAX9919N). They all 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 200 mV (unidirectional operation) or ±100 mV (bidirectional operation).
The MAX9918-20 family operates with a single 5 V supply voltage and are fully specified over the -40°C to +125°C automotive temperature range.
- Current monitoring of inductive loads
- 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
- Reduce protective clamping for high inductive kickback voltage
- Supports wide range of precision AC and DC current sensing applications
- Saves board space
- 8-pin SOIC package
- Single-supply operation (4.5 V to 5.5 V)