Bourns SM915xxL BMS Single-Channel Signal Transformers

Bourns SM915xxL BMS Single-Channel Signal Transformers are reinforced insulation transformers that include common mode chokes for noise rejection in BMS applications. The SM915xxL Signal Transformers work well with the NXP Model MC33771C series and Analog Device’s Model LTC6804/681X series. These components offer a working voltage up to 1500VDC, Hi-Pot isolation voltage up to 6400VDC (SM91519L) and 7640VDC (SM91527L), and an extended -40°C to +125°C operating temperature range.


  • Reinforced insulation per IEC 62477-1, IEC 60664-1, and IEC 62368-1
  • UL recognized, file number E515965 per UL 62368-1
  • Up to 1500VDC working voltage
  • Hi-Pot
    • Up to 6400VDC for the SM91519L
    • Up to 7640VDC for the SM91527L
  • Moisture Sensitivity Level (MSL) 1
  • Supports serial daisy chain/IsoSPI communication
  • Distances
    • 15mm minimum creepage
    • 14mm minimum clearance
  • Developed for use with


  • Battery management systems
  • Energy storage systems


  • 150µH to 450µH open circuit inductance range at 100kHz, 0.1V
  • 4.5µH maximum leakage inductance at 100kHz, 0.1V
  • 1:1 2% turns ratio
  • DCR
    • 0.45Ω maximum on the transformer side
    • 0.8Ω maximum on the CM choke side
  • -1.2dB maximum insertion loss at 4MHz
  • -6dB minimum return loss at 4MHz
  • -50dB typical common-mode rejection ratio, 1MHz to 100MHz range
  • Temperature ranges
    • -40°C to +1258C operating
    • -50°C to +125°C storage
Published: 2021-07-15 | Updated: 2022-03-11