ISO7721DR Digital isolator IC SOIC-8

ISO7721DR Digital Isolator IC SOIC-8 is a high-reliability, dual-channel digital isolator designed to achieve robust galvanic isolation between sensitive low-voltage control circuits and noisy high-voltage systems. This device utilizes Silicon Dioxide ($\text{SiO}_2$) as a barrier, providing superior immunity against magnetic interference and excellent common-mode transient immunity (CMTI). Consequently, the ISO7721DR ensures safe and accurate data transfer across isolation barriers up to 3000 V_RMS. Furthermore, its low power consumption and high data rate capability make it an indispensable component for protecting microcontrollers and other digital circuits in harsh industrial and medical environments. Therefore, system designers choose the ISO7721DR to meet critical safety standards and enhance signal integrity.

Key Features:

• High Isolation Rating: Provides 3000 V_RMS (1 minute) galvanic isolation, protecting low-voltage sides from high-voltage spikes and ground loops.
• Dual-Channel Configuration: Features two independent isolation channels; the ISO7721DR specifically offers one forward and one reverse channel (1/1 directionality).
• High Data Rate: Supports data rates up to 100 Mbps, ensuring fast and real-time communication across the isolation barrier.
• High CMTI: Offers a high Common-Mode Transient Immunity (CMTI) of ±100 kV/μs (typical), maintaining data integrity even with severe noise transients.
• Low Power Consumption: Consumes low power, hence minimizing heat generation and reducing overall system power requirements.
• Wide Supply Voltage Range: Supports both V_CC1 and V_CC2 supply voltages from 2.25 V to 5.5 V, simplifying interface design with various logic levels.

Technical Specifications:

• Isolation Voltage (V_ISO): 3000 V_RMS
• Max Data Rate: 100 Mbps
• Propagation Delay: Typically 10.7 ns
• Minimum CMTI: 100 kV/μs (Transient Immunity)
• Supply Voltage Range (V_CC1, V_CC2): 2.25 V to 5.5 V
• Output Default State: High (Fail-safe state in the absence of input power)
• Operating Temperature Range: −40°C to +125°C

Mechanical Specifications:

• Package Type: SOIC-8 (Small Outline Integrated Circuit, 8-Pin)
• Mounting: Surface-Mount Technology (SMT)
• Barrier Material: Silicon Dioxide ($\text{SiO}_2$)
• Creepage/Clearance: 4 mm (Meeting standard safety requirements)

Dimensions:

• Body Length: ≈ 4.9 mm
• Body Width: ≈ 3.9 mm
• Pin Pitch: 1.27 mm (Standard SOIC pitch)
• Height: ≈ 1.6 mm
• Weight: Consequently, the light weight makes it perfect for compact PCBs.

Pinout and Wiring:

• V_CC1 (Pin 1): Power supply for the input (Channel 1) side.
• GND₁ (Pin 2): Ground reference for the input side.
• IN1 (Pin 3): Digital input channel.
• OUT2 (Pin 4): Digital output channel (Data flows from side 2 to side 1).
• OUT1 (Pin 5): Digital output channel (Data flows from side 1 to side 2).
• IN2 (Pin 6): Digital input channel.
• GND₂ (Pin 7): Ground reference for the output (Channel 2) side.
• V_CC2 (Pin 8): Power supply for the output side.
• Note: Therefore, ensure V_CC1 and V_CC2 derive from separate, isolated power supplies to maintain the integrity of the galvanic isolation barrier.

Datasheet Reference:

• Download Texas Instruments ISO7721 Digital Isolator Datasheet

Commonly Used in:

• Industrial Control: Isolating PLC interfaces, motor drives, and sensor I/O.
• Medical Devices: Furthermore, doctors utilize these isolators in patient monitoring equipment to achieve essential safety isolation.
• Power Supplies: Providing feedback signal isolation in switch-mode power supplies and battery management systems (BMS).

Applications:

• Ground Loop Elimination: Breaking ground loops between different voltage domains in complex systems.
• Isolated Serial Communication: Isolating UART, SPI, and I²C buses between host processors and peripherals.
• High-Side/Low-Side Gate Driver Interface: Safely driving MOSFETs and IGBTs in power conversion applications.

Equivalent Models:

• ADuM1201 (Analog Devices): A widely used dual-channel digital isolator with similar performance and pinout (often interchangeable).
• Si8421 (Silicon Labs): A competitor dual-channel isolator, however, verify the directionality (1/1) before replacing.
• TLP2301 (Toshiba): A high-speed optocoupler that functions as a digital isolator, though it may have different speed and power characteristics.

Package Includes:

• 1 x ISO7721DR High-Speed Dual-Channel Digital Isolator IC SOIC-8