Overview
The ISO7221BD is a dual-channel digital isolator from Texas Instruments, part of the ISO7221x family. These devices are designed to provide galvanic isolation between logic input and output buffers, using TI’s silicon-dioxide (SiO2) isolation barrier. This barrier ensures isolation of up to 4000VPK per VDE, making the device suitable for applications requiring high voltage and ground isolation. The ISO7221BD is particularly useful in scenarios where noise currents or high voltages could interfere with or damage sensitive circuitry.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VCC1, VCC2) | -0.5 | 6 | V | |
| Input Voltage (VI) | -0.5 | VCC + 0.5 | V | |
| Output Current (IO) | -15 | 15 | mA | |
| Maximum Junction Temperature (TJ) | 170 | °C | ||
| Storage Temperature (Tstg) | -65 | 150 | °C | |
| Signaling Rate | 1 Mbps | 150 Mbps | Mbps | |
| Channel-to-Channel Output Skew | 1 ns | ns | ||
| Pulse-Width Distortion (PWD) | 1 ns | ns | ||
| Jitter Content at 150 Mbps | 1 ns | ns | ||
| Transient Immunity | 50 kV/μs | kV/μs | ||
| ESD Protection (HBM) | ±4000 V | V | ||
| Operating Temperature Range | -40 °C | 125 °C | °C |
Key Features
- Signaling rates of 1, 5, 25, and 150 Mbps
- Low channel-to-channel output skew and pulse-width distortion (1 ns max)
- Low jitter content (1 ns typical at 150 Mbps)
- 50 kV/μs typical transient immunity
- Operates with 2.8V (C-Grade), 3.3V, or 5V supplies
- 4 kV ESD protection
- High electromagnetic immunity
- Operating temperature range of -40°C to +125°C
- Typical 28-year life at rated voltage
- Safety-related certifications including DIN EN IEC 60747-17, UL 1577, IEC 62368-1, IEC 61010-1, IEC 60601-1, and GB 4943.1
Applications
- Factory Automation: Modbus, Profibus™, DeviceNet™ data buses
- Computer Peripheral Interface
- Servo Control Interface
- Data Acquisition
Q & A
- What is the primary function of the ISO7221BD?
The ISO7221BD is a dual-channel digital isolator that provides galvanic isolation between logic input and output buffers.
- What are the available signaling rates for the ISO7221BD?
The signaling rates available are 1, 5, 25, and 150 Mbps.
- What is the maximum channel-to-channel output skew?
The maximum channel-to-channel output skew is 1 ns.
- What is the transient immunity of the ISO7221BD?
The transient immunity is 50 kV/μs typical.
- What are the supported supply voltages for the ISO7221BD?
The device operates with 2.8V (C-Grade), 3.3V, or 5V supplies.
- What is the ESD protection level of the ISO7221BD?
The device has 4 kV ESD protection based on the human body model (HBM).
- What is the operating temperature range of the ISO7221BD?
The operating temperature range is -40°C to +125°C.
- What safety certifications does the ISO7221BD have?
The device has certifications including DIN EN IEC 60747-17, UL 1577, IEC 62368-1, IEC 61010-1, IEC 60601-1, and GB 4943.1.
- What are some common applications for the ISO7221BD?
Common applications include factory automation, computer peripheral interfaces, servo control interfaces, and data acquisition.
- How does the ISO7221BD ensure failsafe operation?
The device uses a periodic update pulse to verify the proper dc level of the output. If this pulse is not received every 4 μs, the input is assumed to be unpowered or not actively driven, and the failsafe circuit drives the output to a logic high state.
