New Industry Products

Ultra-High CMTI Isolated Gate Drivers for SiC or GaN FETs

March 07, 2020 by Paul Shepard

The MAX22700–MAX22702 from Maxim Integrated Products are a family of single-channel isolated gate drivers with ultra-high common-mode transient immunity (CMTI) of 300kV/μs (typ). The devices are designed to drive silicon-carbide (SiC) or gallium-nitride (GaN) transistors in various inverter or motor control applications.

All devices have integrated digital galvanic isolation using Maxim’s proprietary process technology. The devices feature variants with output options for gate driver common pin GNDB (MAX22700), Miller clamp (MAX22701), and adjustable undervoltage-lockout UVLO (MAX22702).

In addition, variants are offered as differential (D versions) or single-ended (E versions) inputs. These devices transfer digital signals between circuits with different power domains. All of the devices in the family feature isolation for a withstand voltage rating of 3kVRMS for 60 seconds.

All devices support a minimum pulse width of 20ns with a maximum pulse width distortion of 2ns. The part-to-part propagation delay is matched within 2ns (max) at +25°C ambient temperature, and 5ns (max) over the -40°C to +125°C operating temperature range. This feature reduces the power transistor’s dead time, thus improving overall efficiency.

The MAX22700 and the MAX22702 have a maximum RDSON of 1.25Ω for the low-side driver, and the MAX22701 has an RDSON of 2.5Ω for the low-side driver. All devices have a maximum RDSON of 4.5Ω for the high-side driver.

The MAX22700–MAX22702 can be used to drive SiC or GaN FETs with different output gate drive circuitry and B-side supply voltages.

All of the devices in the MAX22700–MAX22702 family are available in an 8-pin, narrow-body SOIC package with 4mm of creepage and clearance. The package material has a minimum comparative tracking index (CTI) of 600V, which gives it a group I rating in creepage tables. All devices are rated for operation at ambient temperatures of -40°C to +125°C.

Summary of Key Features

  • Matching Propagation Delay
    • 20ns Minimum Pulse Width
    • 35ns Propagation Delay at Room Temperature
    • 2ns Part-to-Part Propagation Delay Matching at Room Temperature
    • 5ns Part-to-Part Propagation Delay Matching over -40°C to +125°C Temperature Range
  • High CMTI (300kV/μs, typ)
  • Robust Galvanic Isolation
    • Withstands 3kVRMS for 60s (VISO)
    • Continuously Withstands 848VRMS (VIOWM)
    • Withstands ±5kV Surge Between GNDA and VSSB with 1.2/50μs Waveform
  • Precision UVLO
  • Options to Support a Broad Range of Applications
    • 3 Output Options: GNDB, Miller Clamp, or Adjustable UVLO
    • 2 Input Configurations: Single-Ended with Enable (E versions) or Differential (D versions)