Interface Selection Guide
Texas Instruments 4Q 2006
Design Considerations
Reliability
— Best-in-class, high voltage
and functional reliability with > 25 years.
Magnetic Immunity
— Immunity from
external magnetic fields to prevent data
corruption is a critical consideration for
industrial applications. 1E6 times higher
magnetic immunity than inductive couplers.
Signaling rate
— TI offers digital isolators
with the highest signaling rates of up to
150 Mbps.
Jitter
— To ensure signal integrity,
jitter reduction is a priority. ISO72xx products
offer the lowest jitter with 1-ns jitter at
150-Mbps PRBS NRZ data input.
Key Features
• 4000-V
peak
isolation
•
•
UL 1577, IEC 60747-5-2
(VDE 0884, Rev. 2)
•
•
IEC 61010-1 and CSA approved
•
•
50-kV/µs transient immunity
• Signaling rate 0 Mbps to 150 Mbps
•
•
Low propagation delay
•
•
Low pulse skew
(pulse-width distortion)
• Low-power sleep mode
• High-electromagnetic immunity
• Low-input current requirement of 10 µA
• Fail-safe output
Technical Information
The ISO72xx is a family of digital isolators
using the industry’s first application of digital
capacitive isolation technology. Digital buffers
capacitively couple data signals through a
silicone-dioxide (SiO
2
) insulation barrier which
provides galvanic isolation of up to 4000 V.
The device receives digital inputs and provides
clean digital outputs while preventing noise
currents and/or excessive voltages from
entering the local ground.
Recently introduced alternative isolation
techniques that use magnetic coupling may
still share the deficiencies of the older opto-
coupler solutions such as a restricted operating
temperature along with new concerns such as
the absence of a fail-safe output, an inability to
operate with DC-only signals and concerns
associated with susceptibility to external
magnetic fields and operating life under high-
voltage conditions. TI isolation solutions are
designed to eliminate such problems.
10
Digital Isolators
➔
Digital Isolators Selection Guide
Low-Power
Transient
Isolation
Sleep
Data Rate
Immunity
Supply
Device
Description Rating
(UL)
Mode
(Max)
(Min)
Voltage
Price*
ISO721
Single channel (TTL)
2500 V
RMS
No
100 Mbps
25 kV/µs
3.3 V, 5 V
1.65
ISO721M
Single channel (CMOS)
2500 V
RMS
Yes
150 Mbps
25 kV/µs
3.3 V, 5 V
1.65
ISO722
Single channel OUT EN (TTL)
2500 V
RMS
Yes
100 Mbps
25 kV/µs
3.3 V, 5 V
1.75
ISO722M
Single channel OUT EN (CMOS)
2500 V
RMS
Yes
150 Mbps
25 kV/µs
3.3 V, 5 V
1.75
ISO150
Dual channel bi-directional
1500 V
RMS
No
80 Mbps
1.6 kV/µs
5 V
8.10
ISO7220A
Dual channel uni-directional (TTL)
2500 V
RMS
No
1 Mbps
25 kV/µs
3.3 V, 5 V
1.10
ISO7220C
Dual channel uni-directional (TTL)
2500 V
RMS
No
25 Mbps
25 kV/µs
3.3 V, 5 V
2.00
ISO7220M
Dual channel uni-directional (CMOS)
2500 V
RMS
No
150 Mbps
25 kV/µs
3.3 V, 5 V
2.50
ISO7221A
Dual channel bi-directional (TTL)
2500 V
RMS
No
1 Mbps
25 kV/µs
3.3 V, 5 V
1.10
ISO7221C
Dual channel bi-directional (TTL)
2500 V
RMS
No
25 Mbps
25 kV/µs
3.3 V, 5 V
2.00
ISO7221M
Dual channel bi-directional (CMOS)
2500 V
RMS
No
150 Mbps
25 kV/µs
3.3 V, 5 V
2.50
*Suggested resale price in U.S. dollars in quantities of 1,000.
New products are listed in
bold red
.
Preview products are listed in
bold blue
.
Magnetic Flux Density vs. Frequency
100E-18
100E-12
100E-6
100E+0
100E+6
0.001
0.01
0.1
1
10
100
MHz
W
b
/m
ISO721
Inductive
IEC61000-4-9
IEC61000-4-8
2
ISO72
1
Isolato
rs
