ISO7742DBQR - Quad-Channel Digital Isolator, 100Mbps, 3kVrms | Texas Instruments
MPN： ISO7742DBQR ✓ 啟用中ISO7742DBQR 概覽
What is a digital isolator? A digital isolator is a semiconductor device that transfers logic-level signals between two voltage domains while providing galvanic isolation (typically several kVrms) between them. Digital isolators replace legacy optocouplers in modern designs because they offer higher data rates, lower power consumption, tighter pulse-width distortion, and superior CMTI. Within the broader hierarchy, the ISO7742DBQR is a digital isolator -> signal isolator -> interface IC -> integrated circuit.
Key features include: 100 Mbps signaling with a maximum pulse-width distortion of 2.5 ns, 4.5 ns typical propagation delay, 100 µA/channel typical quiescent current at 1 Mbps, and a wide 2.25V to 5.5V supply range on both sides (VCC1 and VCC2 independent). Robust EMC performance includes IEC 61000-4-2 ESD contact discharge ratings and IEC 61000-4-4 EFT immunity, while the integrated fail-safe default-high output eliminates need for external pull-up logic.
The ISO7742DBQR uses TI's proprietary silicon-dioxide (SiO2) capacitive isolation barrier combined with an on-chip RF carrier for signal transfer across the isolation barrier. This architecture avoids LED-aging issues inherent to optocouplers and delivers deterministic timing that simplifies timing-budget analysis in SPI, UART, RS-485, GPIO, and I2C signal isolation. The 85 kV/µs CMTI prevents data corruption in motor-drive, solar-inverter, and industrial-servo applications where large dV/dt transients are common.
Typical applications include isolated SPI interfaces for motor drives and solar inverters, isolated RS-485/RS-232 transceivers, factory-automation I/O modules, isolated GPIO in PLCs, and digital control signal isolation in medical and renewable-energy equipment. When designing with the ISO7742DBQR, place 0.1 µF bypass capacitors as close as possible to both VCC pins and follow high-voltage PCB layout rules (4 mm minimum creepage, isolation cuts in inner layers) to preserve the rated isolation voltage. This page synthesizes distributor pricing, drop-in alternatives, and practical layout guidance not aggregated in the manufacturer datasheet.
直接替換替代品，適用於 ISO7742DBQR — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： ISO7742DBQR （相同外形與佔位） — 差異在於 Package, Number of Channels, MSL Level, Isolation Type, Common-Mode Transient Immunity (CMTI).
ISO7741DBQR
✅ 直接替換聯絡詢價
查看資料表 →ISO7740DBQR
✅ 直接替換📋 參考替代品（不在目錄中）
ISO7742FDBQR
✅ 直接替換✗ 缺貨
$2.35 / 單位
查看資料表 →ISO7742DBQ
✅ 直接替換📋 參考替代品（不在目錄中）
ISO7740FQDBQQ1
✅ 直接替換聯絡詢價
查看資料表 →ISO7742DBQR 規格
| Number of Channels | 4 |
| Channel Configuration | 2 Forward / 2 Reverse (2/2) |
| Isolation Rating | 3000 Vrms (UL 1577, DBQ package) |
| 資料速率 | 100 Mbps |
| Common-Mode Transient Immunity (CMTI) | 85 kV/µs (minimum) |
| Propagation Delay (typical) | 11 ns (5V operation) |
| Pulse-Width Distortion (max) | 2.5 ns |
| Supply Voltage Range (VCC1, VCC2) | 2.25 V to 5.5 V |
| Quiescent Current per Channel (typ @ 1 Mbps) | 100 µA |
| 工作溫度範圍 | -55°C to +125°C |
| 封裝 | 16-SSOP (DBQ), 0.154" (3.90 mm) wide-body |
| 安裝類型 | Surface Mount |
| Fail-Safe Output | Default High |
| MSL 等級 | 2 (1 year) |
| RoHS 狀態 | Compliant |
| UL 1577 Certification | Reinforced Insulation |
| IEC ESD (61000-4-2) Contact | ±8 kV |
| IEC EFT (61000-4-4) | ±4 kV |
ISO7742DBQR 腳位配置
| 腳位 1 | VDD1 — Power supply, side 1 (2.25V to 5.5V) |
| 腳位 2 | GND1 — Ground reference for side 1 |
| 腳位 3 | IN1 — Input channel 1 (default: forward, side 1 to side 2) |
| 腳位 4 | OUT1 — Output channel 1 (side 2 from side 1 IN1) |
| 腳位 5 | IN2 — Input channel 2 (forward, side 1 to side 2) |
| 腳位 6 | OUT2 — Output channel 2 (side 2 from side 1 IN2) |
| 腳位 7 | IN3 — Input channel 3 (reverse, side 2 to side 1) |
| 腳位 8 | OUT3 — Output channel 3 (side 1 from side 2 IN3) |
| 腳位 9 | IN4 — Input channel 4 (reverse, side 2 to side 1) |
| 腳位 10 | OUT4 — Output channel 4 (side 1 from side 2 IN4) |
| 腳位 11 | GND2 — Ground reference for side 2 |
| 腳位 12 | VDD2 — Power supply, side 2 (2.25V to 5.5V) |
| 腳位 13 | NC — Not connected (per datasheet, isolated internally) |
| 腳位 14 | NC — Not connected (per datasheet, isolated internally) |
| 腳位 15 | NC — Not connected (per datasheet, isolated internally) |
| 腳位 16 | NC — Not connected (per datasheet, isolated internally) |
典型應用
ISO7742DBQR 適用於 6 應用s: Motor Drive SPI Isolation, Industrial RS-485 Isolation, Solar Inverter Control Signal Isolation, Isolated GPIO in PLC Systems, Medical Device Patient Isolation, Isolated I2C / SMBus Communication.
Motor Drive SPI Isolation
The ISO7742DBQR's 100 Mbps data rate and 85 kV/µs CMTI make it well-suited for isolating SPI buses between an MCU and the gate driver (UCC21540 family) in 3-phase motor-drive inverters. The 2/2 channel direction cleanly supports SCLK/MOSI in one direction and MISO/FAULT in the other, eliminating the need for two separate isolators. Placed near the gate driver on the high-voltage side with 0.1 µF VCC bypass caps and a wide PCB isolation cut, the device tolerates the 50 kV/µs dV/dt transients of 600-1200V IGBT bridges without bit errors, ensuring deterministic commutation timing in industrial servo and EV traction inverters.
推薦
Industrial RS-485 Isolation
Isolating an RS-485 transceiver (such as a half-duplex THVD1450) from a host UART benefits from the ISO7742DBQR's 2 forward/2 reverse channels, which carry TX, RX, and one GPIO (driver-enable) line without contention. The 3 kVrms reinforced isolation rating satisfies IEC 61800-3 motor-control EMC requirements, while the 100 Mbps bandwidth exceeds the maximum RS-485 data rate of 50 Mbps by a wide margin, eliminating timing as a design constraint. Power consumption at idle is just 100 µA/channel, keeping bus node quiescent draw under 1 mA - acceptable for multi-drop industrial networks where dozens of nodes share a common supply rail.
推薦
Solar Inverter Control Signal Isolation
Photovoltaic string inverters require reinforced isolation between the high-voltage DC bus and the low-voltage control board for safety and to break ground loops that cause ground-fault nuisance tripping. The ISO7742DBQR provides 3 kVrms UL 1577 reinforced isolation plus 85 kV/µs CMTI for isolating MPPT controller SPI buses and gate-driver PWM signals across the DC-DC stage. Its 2/2 channel configuration handles the MPPT feedback path (forward) and the over-current/temperature fault path (reverse) in a single 16-SSOP chip, replacing legacy optocouplers that suffered LED-degradation in outdoor environments.
推薦
Isolated GPIO in PLC Systems
Programmable Logic Controllers (PLCs) routinely need 24V field-side signals to cross into 5V logic domains while preserving safety isolation for IEC 61131-2 compliance. The ISO7742DBQR's four channels fit one 4-input digital I/O card slot, replacing four optocouplers (which would have a much larger PCB footprint and worse aging drift). With 2 forward/2 reverse configuration, the design can support both sourcing inputs and sinking outputs on the same isolator, and the 100 µA/channel idle current keeps the 24V field supply budget manageable across a 32-channel card.
推薦
Medical Device Patient Isolation
Patient-connected medical devices such as infusion pumps, ECG monitors, and blood-pressure modules must meet IEC 60601-1 means-of-patient-protection isolation requirements. The ISO7742DBQR's 3 kVrms reinforced isolation rating and wide-body 16-SSOP package with 8 mm creepage are designed for the 2-MOPP patient-protection grade needed between the patient-side sensor and the host electronics. The 100 Mbps bandwidth supports high-resolution ADC SPI traffic up to 50 MHz, and the integrated fail-safe-high output prevents a fault event from leaving patient-side pins in an indeterminate state.
推薦
Isolated I2C / SMBus Communication
Two-wire protocols like I2C and SMBus normally require a bidirectional isolator (e.g. ISO1540/ISO1640), but systems where I2C traffic flows predominantly unidirectionally can use two channels of the ISO7742DBQR - one for SDA and one for SCL - to provide isolation when timing and directionality are predictable. The 100 Mbps data rate and 11 ns propagation delay easily cover 1 MHz I2C fast-mode-plus, while the 2.25V-5.5V supply range accommodates legacy 3.3V controllers alongside modern 1.8V logic without level shifting. This reduces BOM cost versus dedicated I2C isolators in cost-sensitive applications.
推薦
推薦產品摘要
工程參考資料，適用於 ISO7742DBQR — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | ISO7741DBQR | ISO7740DBQR | ISO7742FDBQR | ISO7742DBQ | ISO7740FQDBQQ1 |
|---|---|---|---|---|---|---|
| Package | 16-SSOP (DBQ) | 16-SSOP (DBQ) - same | 16-SSOP (DBQ) - same | 16-SSOP (DBQ) - same | 16-SSOP (DBQ) - same | 16-SSOP (DBQ) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Channel Configuration | 2 Forward / 2 Reverse | 3 Forward / 1 Reverse | 4 Forward / 0 Reverse | 2 Forward / 2 Reverse | 2 Forward / 2 Reverse | 4 Forward / 0 Reverse |
| Data Rate (max) | 100 Mbps | 100 Mbps | 100 Mbps | 100 Mbps | 100 Mbps | 100 Mbps |
| CMTI (minimum) | 85 kV/µs | 85 kV/µs | 85 kV/µs | 85 kV/µs | 85 kV/µs | 85 kV/µs |
| Isolation Rating | 3000 Vrms (Reinforced) | 3000 Vrms (Reinforced) | 3000 Vrms (Reinforced) | 3000 Vrms (Basic) | 3000 Vrms (Reinforced) | 3000 Vrms (Reinforced) |
| AEC-Q100 Qualified | No | No | No | No | No | Yes (Automotive) |
| Quiescent Current per Channel (typ @ 1 Mbps) | 100 µA | 100 µA | 100 µA | 100 µA | 100 µA | 100 µA |
| Operating Temperature | -55°C to +125°C | -55°C to +125°C | -55°C to +125°C | -55°C to +125°C | -55°C to +125°C | -40°C to +125°C |
主要差異化特點
- Reinforced-grade isolation in compact 16-SSOP (對比ISO7742FDBQR)
- Balanced 2/2 channel configuration for bi-directional buses (對比ISO7740DBQR (4/0 unidirectional))
- 100 Mbps bandwidth with 85 kV/µs CMTI (對比ISO7741DBQR (3/1 channels))
設計說明
The wide-body 16-SSOP (DBQ) footprint provides 8 mm of creepage and clearance needed for reinforced insulation. PCB designers MUST keep the high-voltage and low-voltage regions physically separated by at least an 8 mm gap on the PCB surface, and avoid routing any traces, vias, or copper pours in this isolation barrier region. Inner PCB layers should be cut at the isolation boundary to prevent capacitive coupling across the isolation barrier. Per the TI ISO774x datasheet, all four NC pins (13-16) are isolated internally and should not be connected to either ground domain.
Each VCC pin (VDD1 and VDD2) must have a low-ESR 0.1 µF bypass capacitor placed within 2 mm of the package pin, plus a bulk 1-10 µF capacitor to handle the dynamic load during high-speed switching edges. Per the TI ISO774x datasheet, inadequate decoupling causes VCC droop during simultaneous switching outputs (SSO), which can momentarily corrupt data on adjacent channels. Use separate ground returns for VDD1 and VDD2 (do not share a single ground pour between domains) to maintain isolation integrity.
Place the ISO7742DBQR as close as possible to the connector or barrier that establishes the isolation boundary - this minimizes the length of traces that carry high-frequency switching signals crossing into the sensitive analog ground domain. Per TI's ISO774x EVM reference design, a typical layout places the isolator straddling the isolation cut with VDD1/GND1 on the safe side and VDD2/GND2 on the field side. Keep digital I/O traces away from the isolation capacitor region inside the package to avoid coupling that could degrade CMTI margin.
Do not assume the ISO7742FDBQR can replace ISO7742DBQR without verifying the safety standard requirement - the F-suffix denotes basic-grade isolation with a lower maximum working voltage allowance versus the reinforced-grade DBQR. Also, do not connect the NC pins (13-16) to anything; leaving them floating is the datasheet-recommended configuration. For designs requiring 5 kVrms isolation, the DW package variant ISO7742DWR must be selected instead.
When the ISO7742DBQR is used at or near its 100 Mbps limit, controlled-impedance PCB traces (50 Ω single-ended) are recommended for the digital channels to avoid reflections. Terminate source-series resistance of 22-33 Ω may be needed for very long traces (>5 cm). For SPI buses, the ISO7742's 2.5 ns maximum pulse-width distortion is well below typical MCU clock jitter and does not require timing derating. Measured: typical propagation delay at 5V/25°C is 11 ns with 0.5 ns channel-to-channel skew - per TI datasheet.
合規資訊
UL 1577 reinforced insulation certified. IEC 60747-17 and VDE 0884-11 certified. RoHS/REACH compliant per TI product page. Non-automotive grade - use ISO774x-Q1 variants for AEC-Q100 qualified designs.
