Key Specs

SpecValueConditionSource
3db Bandwidth90 kHzDigi-Key
Amplifier TypeCurrent SenseDigi-Key
Current Input Bias39 µADigi-Key
Mounting TypeSurface MountDigi-Key
Number Of Circuits1Digi-Key
Operating Temperature Range-40°C ~ 125°CDigi-Key
Output TypeRail-to-RailDigi-Key
Package Case6-TSSOP, SC-88, SOT-363Digi-Key
Quiescent Current (Typ)40µADigi-Key
Slew Rate1V/µsDigi-Key
Supplier Device PackageSC-88/SC70-6/SOT-363Digi-Key
Voltage Input Offset5 µVDigi-Key
Voltage Supply Span (Max)26 VDigi-Key
Voltage Supply Span (Min)2.2 VDigi-Key

When To Use

  1. Battery-powered sensor front-end → 3.3V @ 10mA: The 40µA quiescent current keeps battery drain minimal during sleep, extending device life. A synchronous buck controller would draw much higher quiescent current, causing premature battery exhaustion in low-duty applications.

  2. Current sense amplification in motor control → 12V supply monitoring: The current sense amplifier with 39µA input bias and 5µV offset voltage enables accurate low-level current measurement without introducing thermal drift. Using a generic high-speed op amp risks thermal runaway or offset drift that corrupts feedback control.

  3. Precision analog front end → 5V rail, noise-sensitive: The rail-to-rail output and 90kHz bandwidth are well matched for moderate-speed sensor readout with minimal distortion. Higher bandwidth amplifiers may introduce switching noise or require complex filtering, risking latch-up or signal integrity issues.

When Not To Use

  1. High current power stage control > 5A: The device’s single-circuit design and quiescent current limit its ability to handle high current loads. Use a high-current synchronous buck with external FETs to manage current and thermal dissipation safely.

  2. High-frequency switching > 500kHz for compact magnetics: The 90kHz bandwidth and 1V/µs slew rate limit the switching frequency and transient response. Choose a high-frequency buck controller designed for GHz-class switching to avoid instability and excessive losses.

  3. Low dropout linear regulation < 1V differential: The minimum supply voltage of 2.2V and rail-to-rail output are insufficient for low dropout operation under tight headroom conditions. An LDO regulator is better suited to minimize noise and dropout voltage in this scenario.

Application Notes

Gotchas

  1. [Offset drift with temperature]: The 5µV input offset voltage specification is typical at room temperature; offset can drift significantly near the -40°C or 125°C extremes, causing inaccurate current sensing and control errors.
    Fix: Validate offset drift over full operating temperature in your test setup and consider calibration or temperature compensation in firmware.

  2. [Input bias current interacting with high-value shunt resistor]: Designers sometimes select large sense resistors to increase signal amplitude, ignoring the 39µA input bias current. This causes non-linear voltage drops and distorted current measurements, visible as offset shifts and hysteresis on scope.
    Fix: Keep sense resistor values below 100mΩ and verify linearity with bench tests.

  3. [Layout coupling from SW node]: Placing the switching node trace adjacent to amplifier input lines can cause high-frequency noise injection, resulting in output oscillations or sporadic rail-to-rail output swings.
    Fix: Route the SW node away from amplifier pins and use ground shields or guard traces.

  4. [Startup undervoltage lockout and output phase delay]: If the supply voltage ramps slowly or is near the 2.2V minimum, the amplifier output can saturate or delay settling, causing control loop instability at power-up.
    Fix: Implement a power-good or undervoltage lockout signal upstream and verify output settling time at minimum operating voltage.