1 Features
1• Signaling Rate > 50 Mbps
• Default Output 'High' and 'Low' Options
• Low Power Consumption: Typical ICC per Channel
(3.3-V Supplies):
– ISO7420: 1.4 mA at 1 Mbps, 2.5 mA at
25 Mbps
– ISO7421: 1.8 mA at 1 Mbps, 2.8 mA at
25 Mbps
• Low Propagation Delay: 7 ns Typical
• Low Pulse Skew: 200 ps Typical
• Wide TA Range Specified: –40°C to 125°C
• 50-KV/μs Transient Immunity, Typical
• Isolation Barrier Life: > 25 Years
• Operates from 3-V to 5.5-V Supply Levels
• 3.3-V and 5-V Level Translation
• Narrow Body SOIC-8 Package
• Safety and Regulatory Approvals:
– 4242 VPK Isolation per DIN V VDE V 0884-10
and DIN EN 61010-1
– 2500 V RMS Isolation for 1 minute per UL 1577
– CSA Component Acceptance Notice 5A, IEC
60950-1 and IEC 61010-1 Standards
– CQC Certification per GB4943.1-2011

2 Applications
• Opto-Coupler Replacement in:
– Industrial FieldBus
– ProfiBus
– ModBus
– DeviceNet™ Data Buses
– Servo Control Interface
– Motor Control
– Power Supplies
– Battery Packs

3 Description
ISO742x provide galvanic isolation up to 2500 VRMS
for 1 minute per UL and 4242 VPK per VDE. These devices have two isolated channels. Each channel
has a logic input and output buffer separated by a
silicon dioxide (SiO2) insulation barrier. Used in
conjunction with isolated power supplies, these
devices prevent noise currents on a data bus or other
circuit from entering the local ground and interfering
with or damaging sensitive circuitry. ISO7420 has
both channels in the same direction while ISO7421
has the two channels in opposite direction. In case of
input power or signal loss, default output is 'low' for
devices with suffix 'F' and 'high' for devices without
suffix 'F'. ISO742x have no integrated noise filter and
thus have fast propagation delays.
These devices have TTL input thresholds and
operate from 3-V to 5.5-V supplies. All inputs are 5-V
tolerant when supplied from a 3.3-V supply.