ISO7420_15 Datasheet, PDF (1/28 Pages) Texas Instruments – ISO742x Low-Power Dual-Channel Digital Isolators

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ISO7420, ISO7420M, ISO7421
SLLS984I – JUNE 2009 – REVISED JULY 2015
ISO742x Low-Power Dual-Channel Digital Isolators
1 Features
•1 Highest Signaling Rate: 1 Mbps
• Low Power Consumption, Typical I_CC per Channel
(3.3-V operation):
– ISO7420: 1.1 mA, ISO7421: 1.5 mA
• Low Propagation Delay – 9 ns Typical
• Low Skew – 300 ps Typical
• Wide T_A Range: –40°C to 125°C (M-Grade)
• 50-kV/μs Transient Immunity, Typical
• Over 25-Year Isolation Integrity at Rated Voltage
• Operates From 3.3-V and 5-V Supply and Logic
Levels
• 3.3-V and 5-V Level Translation
• Narrow Body SOIC-8 Package
• Safety and Regulatory Approvals:
– 4242 V_PK 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
• Optocoupler Replacement in:
– Industrial Fieldbus
– Profibus
– Modbus
– DeviceNet™ Data Buses
– Servo Control Interface
– Motor Control
– Power Supplies
– Battery Packs
3 Description
The ISO7420, ISO7420M and ISO7421 provide
galvanic isolation up to 2500 V_RMS for 1 minute per
UL. These digital isolators have two isolated
channels. Each isolation 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. The suffix M indicates wide
temperature range (–40°C to 125°C).
These devices have TTL input thresholds and require
two supply voltages, 3.3 or 5 V, or any combination.
All inputs are 5-V tolerant when supplied from a 3.3-V
supply.
Note: The ISO7420 and ISO7421 are specified for
signaling rates up to 1 Mbps. Due to their fast
response time, under most cases, these devices will
also transmit data with much shorter pulse widths.
Designers should add external filtering to remove
spurious signals with input pulse duration <20 ns if
desired.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
ISO7420
ISO7420M
SOIC (8)
4.90 mm × 3.91 mm
ISO7421
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Simplified Schematic
V_CCI
V_CCO
Isolation
Capacitor
INx
OUTx
GNDI
GNDO
V_CCI and GNDI are supply and ground connections respectively for the input channels.
V_CCO and GNDO are supply and ground connections respectively for the output channels.
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. UNLESS OTHERWISE NOTED, this document contains PRODUCTION
DATA.