1 Features
1• Common-mode input range: –0.2 V to +26 V
• High accuracy amplifier:
– Offset voltage at TA = 25°C
– 500 μV (maximum) at VCM = 12 V
– 150 μV (maximum) at VCM = 0 V
– Offset voltage drift: 1 μV/°C (maximum)
– Gain error: 1% (maximum) at 25°C
– Gain error drift: 20 ppm/°C (maximum)
• Available amplifier gains:
– INA381A1: 20 V/V
– INA381A2: 50 V/V
– INA381A3: 100 V/V
– INA381A4: 200 V/V
• Open-drain comparator:
– Hysteresis: 50 mV
– Propagation delay: 400 ns (typ)
– Alert threshold set through external reference
voltage
– Supports transparent and latching modes
• Packages: VSSOP-10 and WSON-8

2 Applications
• Merchant network and server PSU
• Merchant DC/DC
• DC-input BLDC motor drive
• Cordless power tool
• Headsets, headphones and earbuds

3 Description
The INA381 includes both a 26-V common-mode,
current-sensing amplifier and a high-speed
comparator. This device detects overcurrent
conditions by measuring the voltage developed
across a current-shunt resistor and comparing that
voltage to a user-defined threshold limit set by the
comparator reference pin. The current-shunt monitor
can measure differential voltage signals on commonmode
voltages that vary from –0.2 V up to 26 V,
independent of the supply voltage.
The open-drain alert output can be configured to
operate in two modes: transparent or latched. In
transparent mode, the output status follows the input
state. In latched mode, the alert output is cleared only
when the latch is reset. The standalone comparator
large-signal alert response time is less than 2 μs,
allowing for quick detection of overcurrent events.
The total system overcurrent protection response
time provided by the INA381 is less than 10 μs.
This device operates from a single 2.7-V to 5.5-V
supply, drawing a maximum supply current of 350 μA.
The device is specified over an operating temperature
range of –40°C to +125°C, and is available in 8-pin
WSON and 10-pin VSSOP packages.