General-purpose capacitive isolator for harsh environments
The Texas Instruments ISO7241AMDWREP is a 4-channel, unidirectional digital isolator using capacitive coupling technology. It is designed for general-purpose isolation of digital signals where galvanic isolation is required between two circuits operating from separate ground references.
1Mbps data rate and propagation delay — what they mean for timing closure
With a maximum propagation delay of 95 ns (both tpLH and tpHL) and a pulse-width distortion of 10 ns max, this isolator can handle 1Mbps signaling with enough margin for most industrial fieldbus interfaces (RS-485, CAN, SPI) when the bus clock stays under 1 MHz. The 2 ns typical rise/fall time keeps edge-rate-induced ringing manageable on short PCB traces, but at 1Mbps the 95 ns delay adds roughly 10% of the bit period — budget that into your timing analysis if the link is cascaded through multiple isolators.
Supply range and channel configuration
The supply voltage range of 3.15V to 5.5V on each side allows the ISO7241AMDWREP to bridge logic levels between a 3.3V MCU domain and a 5V peripheral domain without an external level shifter. The channel arrangement is 3 inputs on side 1 and 1 input on side 2 — three forward channels and one reverse channel. This suits applications like isolated SPI where you need three signals (SCLK, MOSI, CS) going one way and one signal (MISO) returning. The unidirectional channel type means each channel drives in only one direction; there is no built-in direction control for bidirectional buses like I2C.
Common-mode transient immunity and isolation rating
A minimum common-mode transient immunity (CMTI) of 25 kV/µs ensures the isolator does not glitch when fast voltage transients couple across the isolation barrier — a critical parameter in motor-drive inverters and switched-mode power supplies where the ground potential can jump at tens of kV/µs. The 4000Vpk isolation voltage supports reinforced insulation for mains-connected equipment per IEC 60747-5-5, though the part does not include an integrated isolated DC-DC converter; you must supply isolated power externally.
Package and footprint
The surface-mount package is compatible with standard reflow soldering.