Overview
The ISO7221MD is a dual-channel digital isolator produced by Texas Instruments. This device is part of the ISO7221x family, which is designed to provide galvanic isolation between logic input and output buffers using a silicon-dioxide (SiO2) isolation barrier. This barrier offers up to 4000VPK of isolation per VDE, making it suitable for applications requiring high voltage and ground isolation. The device is used in conjunction with isolated power supplies to prevent noise currents from interfering with or damaging sensitive circuitry. Although the ISO7221MD is currently obsolete and not recommended for new designs, it remains relevant for existing systems and legacy applications.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Signaling Rate | 0 - 150 | Mbps |
| Propagation Delay | 12 | ns (typical) |
| Pulse Skew | 0.5 | ns (typical) |
| Supply Voltage | 2.8, 3.3, 5 | V |
| Input Voltage Tolerance | 5V tolerant when supplied from 2.8V or 3.3V | V |
| Output Current | 4 | mA (CMOS) |
| Operating Temperature Range | -40 to +125 | °C |
| Isolation Voltage | 4000VPK (VDE), 2500 VRMS (UL 1577) | V |
| ESD Protection | ±4000 V (HBM), ±1000 V (CDM) | V |
Key Features
- Dual-channel digital isolator with channels oriented in opposite directions to facilitate PCB layout.
- Galvanic isolation up to 4000VPK per VDE and 2500 VRMS per UL 1577.
- Signaling rates from 0 Mbps (DC) to 150 Mbps.
- Low propagation delay (12 ns typical) and pulse skew (0.5 ns typical).
- Failsafe output circuitry that drives the output to a logic high state if the dc-refresh pulse is not received within 4 μs.
- Low-power sleep mode and high electromagnetic immunity.
- Operates from 2.8V, 3.3V, or 5V supplies with 5V tolerant inputs and 4mA CMOS outputs.
- Safety-related certifications including DIN EN IEC 60747-17, UL 1577, IEC 62368-1, and IEC 61010-1).
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 ISO7221MD?
The ISO7221MD is a dual-channel digital isolator that provides galvanic isolation between logic input and output buffers using a silicon-dioxide (SiO2) isolation barrier.
- What are the signaling rate options for the ISO7221MD?
The signaling rates range from 0 Mbps (DC) to 150 Mbps.
- What are the supply voltage options for the ISO7221MD?
The device operates from 2.8V, 3.3V, or 5V supplies.
- What is the isolation voltage rating of the ISO7221MD?
The isolation voltage rating is up to 4000VPK per VDE and 2500 VRMS per UL 1577.
- What safety certifications does the ISO7221MD have?
The device has certifications including DIN EN IEC 60747-17, UL 1577, IEC 62368-1, and IEC 61010-1.
- What is the operating temperature range of the ISO7221MD?
The operating temperature range is from -40°C to +125°C.
- Does the ISO7221MD have failsafe output circuitry?
Yes, the device has failsafe output circuitry that drives the output to a logic high state if the dc-refresh pulse is not received within 4 μs.
- What are some common applications for the ISO7221MD?
Common applications include factory automation, computer peripheral interfaces, servo control interfaces, and data acquisition.
- Is the ISO7221MD still in production?
No, the ISO7221MD is obsolete and not recommended for new designs.
- What is the typical propagation delay of the ISO7221MD?
The typical propagation delay is 12 ns.
