Dual Digital Isolators
The IC is dual-channel digital isolator. To facilitate PCB layout, the channels are oriented in the same direction in the IC. The device have a logic input and output buffer located by different chips, providing galvanic isolation of up to 2000 v. Used in conjunction with isolated power supplies, these devices block high voltage, isolate grounds, and prevent noise currents on a data bus or other circuits from entering the local ground and interfering with or damaging sensitive circuitry. A binary input signal is conditioned, translated to a balanced signal, then differentiated by the capacitive isolation barrier. Across the isolation barrier, a differential comparator receives the logic transition information, then sets or resets a flip-flop and the output circuit accordingly. A periodic update pulse is sent across the barrier to ensure the proper dc level of the output. If this dc-refresh pulse is not received every 4 μs, the input is assumed to be unpowered or not being actively driven, and the failsafe circuit drives the output to a logic high state. The small capacitance and resulting time constant provide very fast operation with signaling rates available from 0 Mbps (DC) to 150 Mbps. These devices are characterized for operation over the ambient temperature range of -40°C to 125°C.
Features
- 1, 25 and 150-Mbps Signaling Rate Options.
- Low Channel-to-Channel Output Skew;
- Low Pulse-Width Distortion (PWD);
- 2000–Vpeak Isolation, 560 V peak VIORM
- 50 kV/µs Typical Transient Immunity
- Operates with 3.3-V or 5-V Supplies
- 4 kV ESD Protection
- High Electromagnetic Immunity
- -40°C to 125°C Operating Range
Applications
- Power supply management interface
- Servo Control Interface
- Data Acquisition