Isolated FET Driver for Industrial Relay Replacement Applications

Silicon Labs recently introduced a new CMOS-based isolated field effect transistor (FET) driver family for industrial and automotive applications. The family enables you to use your preferred application-specific, high-volume FETs to replace old electromechanical relays (EMRs) and optocoupler-based, solid-state relays (SSRs).Si875x Silicon Labs

The new Si875x family features the industry’s first isolated FET drivers designed to transfer power across an integrated CMOS isolation barrier. When paired with a discrete FET, the Si875x drivers provide a superb EMR/SSR replacement solution for motor and valve controllers, HVAC relays, battery monitoring, and a variety of other applications.

The Si875x isolated FET driver family’s features and specs:

  • Industry’s first CMOS isolation-based SSR solution, supporting application-specific FETs
  • Best-in-class noise immunity, high reliability and 2.5 kVRMS isolation rating
  • Long lifetimes under high-voltage conditions (100 years at 1000 V)
  • Efficient switching: 10.3 V at the gate with only 1 mA of input current
  • Wide input voltage of 2.25 to 5.5 V enables power savings
  • Unique pin feature optimizes power consumption/switching time trade-off
  • Miller clamping prevents unintended turn on of external FET
  • Small SOIC-8 package integrates isolation and power capacitors for low-power applications
  • AEC-Q100-qualified automotive-grade device options

The Si875x devices come in a small SOIC-8 package. They are available in both industrial (–40°C to 105°C) or automotive (–40°C to 125°C) ambient temperature operating range options. Pricing in 10,000-unit quantities begins at $0.96 for industrial versions and $1.20 for automotive temperature options.

Evaluation kits are available. The Si8751-KIT (digital input) and Si8752-KIT (LED emulator input) evaluation kits cost $39.99 each.

Source: Silicon Labs