Current-sense amplifier in a 5-pin SC-70
The supply range from 2.7 V to 20 V lets it run off common rails (3.3 V, 5 V, 12 V) without a secondary regulator.
Package and mounting
The 2 V/µs slew rate and 1.1 MHz gain-bandwidth product set the usable bandwidth for detecting fast current transients. For a 100 mV shunt signal, the amplifier settles to within 1% in roughly 1 µs — fast enough for overcurrent detection in a 100 kHz switching converter. The 370 µA supply current keeps the thermal budget low in the SC-70 package, which has limited copper area for heat sinking.
Input offset and bias — what to budget in the measurement path
The offset contributes a fixed error at low shunt voltages; for a 10 mV full-scale signal the offset adds 0.15% error, which is acceptable for most automotive current-monitoring loops. The 20 µA bias current flows through the shunt — with a 1 mΩ shunt that adds 20 nV, negligible in practice.
Package and footprint — SC-70-5 layout notes
The SC-70-5 (also known as SOT-353) package has a 2.0 mm × 2.1 mm body with 0.65 mm pin pitch. The small footprint saves board area, but the lack of an exposed thermal pad means all heat dissipates through the leads and the small copper pad. At 370 µA supply current the self-heating is minimal — junction rise stays under 5°C even in still air. The supplier device package is SC-70-5.
Lifecycle and compliance
It is ROHS3 compliant, with no exemptions for lead in solder. No successor part has been announced.