What this digital isolator does in the assembly
The Texas Instruments ISO7741QDBQQ1 is a 4-channel digital isolator using capacitive coupling to pass digital signals across a galvanic isolation barrier. It is part of the ISO7741 family and carries AEC-Q100 qualification for automotive applications. The part provides 2500Vrms isolation between input and output sides, with a unidirectional channel configuration — three channels on side 1 and one on side 2. This makes it a straightforward fit for isolating SPI, UART, or general-purpose GPIO lines where the direction of each signal is fixed.
Data rate and timing — what 100Mbps and 16ns propagation delay mean
Rated for 100Mbps data rate, this isolator handles most industrial communication buses including SPI at 50 MHz or full-speed CAN FD. The maximum propagation delay of 16ns in either direction (tpLH / tpHL) keeps timing closure manageable on a mixed-signal board; you will want to account for it in the bus timing budget, especially if daisy-chaining multiple isolators. Pulse width distortion is held to 4.9ns max, so the duty cycle stays close to 50% through the barrier — useful for clock signals or PWM where edge symmetry matters.
85 kV/µs common-mode transient immunity — why it matters for motor drives and inverters
The minimum common-mode transient immunity of 85kV/µs is the spec that earns this part a spot in automotive traction inverters and industrial motor drives. Fast-switching SiC or GaN power stages can slam the isolation barrier with several kilovolts per microsecond; if the isolator cannot reject that edge, data corrupts or the output glitches. At 85kV/µs the ISO7741QDBQQ1 sits well above the requirement for most 600V–1200V inverter designs, giving margin against the switching noise.
Supply range and operating temperature
Operates from 2.25V to 5.5V on each side independently, so you can run the microcontroller side at 3.3V and the isolated side at 5V without a level shifter. No isolated power is integrated — each side needs its own local supply rail.
Package and footprint
Housed in a 16-pin SSOP package (3.90mm body width) with a standard 0.154-inch pitch. Surface-mount only. The small footprint keeps the isolation creepage distance short — verify the clearance meets your safety standard if working with mains voltages.
Lifecycle and sourcing
Listed as Active in the lifecycle status, meaning TI continues to manufacture and support this part for new designs. The base product number is ISO7741; the QDBQQ1 suffix identifies the automotive-grade, 16-SSOP variant.