Robust battery management system communications

A communication interface circuit, comprising:

• a first half-bridge driver circuit and a second half-bridge driver circuit,
• a first internal isolation node coupled to the first half-bridge driver circuit,
• a second internal isolation node coupled to the second half-bridge driver circuit,
• a first external isolation node and a second external isolation node,
• a first resistive network coupled between the first internal isolation node and the first external isolation node,
• a second resistive network coupled between the second internal isolation node and the second external isolation node,
• a voltage comparator circuit coupled to the first external isolation node and the second external isolation node,
• a clamping circuit coupled to the first internal isolation node and the second internal isolation node, the clamping circuit configured to limit voltage excursions at the first internal isolation node and the second internal isolation node, and
• an electrostatic discharge (ESD) protection circuit coupled between the first external isolation node and the second external isolation node, the ESD protection circuit configured with trigger voltages exceeding a sum of a clamping voltage and voltage drops across the first resistive network and the second resistive network.

A method of operating a communication interface circuit during electromagnetic compatibility testing, the method comprising:

• implementing voltage clamping at a first internal isolation node and a second internal isolation node;
• generating differential signals using a first half-bridge driver circuit coupled to the first internal isolation node and a second half-bridge driver circuit coupled to the second internal isolation node;
• developing voltage drops across a first resistive network coupled between the first internal isolation node and a first external isolation node and a second resistive network coupled between the second internal isolation node and a second external isolation node;
• and
• detecting differential voltages between the first external isolation node and the second external isolation node using a voltage comparator circuit while maintaining electrostatic discharge protection trigger voltages above a sum of a clamping voltage and the voltage drops.