Texas Instruments ISO7741Tx-Q1 4-Channel Reinforced Digital Isolator

Texas Instruments ISO7741Tx-Q1 Quad-Channel Reinforced Digital Isolators are grade 1 high-performance isolators with an integrated transformer driver with 5000VRMS isolation ratings per UL 1577. According to VDE, CSA, TUV, and CQC, this device meets reinforced insulation ratings. The ISO7741Tx-Q1 device provides low emissions and high electromagnetic immunity at low power consumption while isolating LVCMOS or CMOS digital I/Os. Each isolation channel has a logic input and output buffer separated by a double capacitive silicon dioxide (SiO₂) insulation barrier. If the input power or signal is lost, the default output is high for devices without the suffix F and low for devices with the suffix F.

The ISO7741Tx-Q1 has a low-noise, low-EMI push-pull transformer driver designed explicitly for isolated power supplies in a small form factor. The device drives low-profile, center-tapped transformers from a 2.25V to 5.5V DC power supply. Very low EMI and noise are achieved through Spread Spectrum Clocking (SSC) and slew rate control of the output switch voltage. The ISO7741Tx-Q1 consists of an oscillator and a gate drive circuit providing complementary output signals to drive ground-referenced N-channel power switches. The device includes two 1A Power-MOSFET switches to provide start-up under heavy loads. The internal protection features include a 1.7A current limiting, thermal shutdown, under-voltage lockout, and break-before-make circuitry. ISO7741Tx-Q1 includes a soft-start feature that prevents high in-rush current during power-up with large load capacitors. ISO7741TA-Q1 has a 160kHz internal oscillator for applications that need to minimize emissions, whereas ISO7741TB-Q1 has a 420kHz internal oscillator for applications that require higher efficiency and smaller transformer size.

The Texas Instruments ISO7741Tx-Q1 is available in a 16-pin DW package. Its operation temperature range is -40°C to 125°C.

Features

Qualified for automotive applications AEC-Q100 qualified with the following results
- Device temperature grade 1 (–40°C to 125°C ambient operating temperature)
Functional safety-capable
- Documentation available to aid ISO 26262 system design
100Mbps data rate
Robust isolation barrier
- > 30-year projected lifetime at 1500VRMS working voltage
- 5000V_RMS rating
- Up to 12.8kV surge capability
- ±150kV/µs typical CMTI for digital isolator
2.25V to 5.5V wide supply range
2.25V to 5.5V level translation

Default output high (ISO7741T) and low (ISO7741FT) options
Low power consumption, typically 1.5mA per channel at 1Mbps
10.7ns typical (5V supplies) low propagation delay
Robust electromagnetic compatibility (EMC)
- System-level ESD, EFT, and surge immunity
Push-pull driver for transformers
High output drive of 0.7A at 5V supply
Low R_ON 0.4Ω max at 4.5V supply
Spread spectrum clocking
1.7A current-limit
Safety-related certifications (pending)
- DIN EN IEC 60747-17 (VDE 0884-17)
- UL 1577 component recognition program
- IEC 61010-1, IEC 62368-1, IEC 60601-1, and GB 4943.1 certifications

Applications

Hybrid, electric and powertrain system (EV/HEV)
- Battery management system (BMS)
- On-board charger
- Traction inverter and motor control
- DC/DC converter