SM91595AL Automotive-Grade BMS Transformers

Introduction

Bourns’ SM91595AL is an automotive-grade, single-channel BMS signal-transformer series for isolated battery-management communications. Its technically notable feature is the integration of a common-mode choke with a reinforced-insulation transformer, combining galvanic isolation and common-mode noise reduction in one magnetic component.

The series is intended for the high-voltage environments found in electric-vehicle and energy-storage battery systems, with reinforced insulation specified to IEC 62477-1:2022 and IEC 62368-1:2018.

What it does

The SM91595AL transfers communication signals across an isolation barrier in a battery-management system while helping attenuate common-mode noise through its integrated choke. It uses a 1:1 turns ratio and supports working voltages up to 1500 VDC, with Hi-Pot isolation rated to 6400 VDC.

Electrical characteristics include an inductance range of 150 μH to 450 μH and maximum leakage inductance of 0.6 μH. Maximum DC resistance is specified as 0.6 Ω for pins 1–3 and 0.7 Ω for pins 4–6.

The transformer is qualified for operation from -40°C to +125°C. It is AEC-Q200 compliant, RoHS compliant, UL recognized, and designed for automated assembly.

Applications

• Isolated communication links between battery-management sections in electric vehicles
• Battery-management electronics for energy-storage systems
• High-voltage battery-monitoring architectures requiring reinforced isolation
• BMS signal paths where common-mode noise reduction is required alongside isolation

Design considerations

The SM91595AL is a single-channel device with a 1:1 turns ratio, so system designers should account for the required communication topology and isolation-channel count when selecting it.

Its isolation system includes creepage and clearance distances greater than 23.0 mm. The creepage specification applies to pollution degree 2 and material group CTI I, while the clearance specification is stated for Overvoltage Category II and installations up to 5000 m above sea level. These values can be relevant when evaluating PCB layout and insulation coordination in high-voltage battery assemblies.

The component’s -40°C to +125°C operating range and AEC-Q200 compliance make it relevant to automotive-temperature environments, while the integrated common-mode choke may reduce the need for a separate magnetic noise-suppression component in the communication path.

Availability and further information

Further technical information is available through the Mouser Electronics source link and the datasheet link provided on this page.