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SLLS868A – SEPTEMBER 2007 – REVISED DECEMBER 2007
QUAD DIGITAL ISOLATORS
1
•
FEATURES
1, 25, and 150-Mbps Signaling Rate Options
– Low Channel-to-Channel Output Skew;
1 ns Max
– Low Pulse-Width Distortion (PWD);
2 ns Max
– Low Jitter Content; 1 ns Typ at 150 Mbps
Typical 25-Year Life at Rated Working Voltage
(see application note
and
4000-V
peak
Isolation, 560-V
peak
Working Voltage
UL 1577 Certified
4 kV ESD Protection
Operate With 3.3-V or 5-V Supplies
•
•
•
•
•
•
High Electromagnetic Immunity
(see application report
–40°C to 125°C Operating Range
APPLICATIONS
Industrial Fieldbus
Computer Peripheral Interface
Servo Control Interface
Data Acquisition
•
•
•
•
•
DESCRIPTION
The ISO7240, ISO7241 and ISO7242 are quad-channel digital isolators with multiple channel configurations and
output enable functions. These devices have logic input and output buffers separated by TI’s silicon dioxide
(SiO
2
) isolation barrier. Used in conjunction with isolated power supplies, these devices block high voltage,
isolate grounds, and prevent noise currents from entering the local ground and interfering with or damaging
sensitive circuitry.
The ISO7240 has all four channels in the same direction while the ISO7241 has three channels the same
direction and one channel in opposition. The ISO7242 has two channels in each direction.
The A and C option devices have TTL input thresholds and a noise-filter at the input that prevents transient
pulses from being passed to the output of the device. The M option devices have CMOS Vcc/2 input thresholds
and do not have the input noise-filter or the additional propagation delay.
A periodic update pulse is sent across the barrier to ensure the proper dc level of the output. If this dc-refresh
pulse is not received, the input is assumed to be unpowered or not being actively driven, and the failsafe circuit
drives the output to a logic high state. (Contact TI for a logic low failsafe option).
These devices may be powered from either 3.3-V or 5-V supplies on either side in any 3.3-V / 3.3-V, 5-V / 5-V,
5-V / 3.3-V, or 3.3-V / 5-V combination. Note that the signal input pins are 5-V tolerant regardless of the voltage
supply level being used.
These devices are characterized for operation over the ambient temperature range of –40°C to 125°C.
ISO7240
V
CC1
GND1
IN
A
IN
B
IN
C
IN
D
NC
GND1
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
CC2
GND2
OUT
A
OUT
B
OUT
C
OUT
D
EN
GND2
V
CC1
GND1
IN
A
IN
B
IN
C
OUT
D
EN
1
GND1
1
2
3
4
5
6
7
8
ISO7241
16
15
14
13
12
11
10
9
V
CC2
GND2
OUT
A
OUT
B
OUT
C
IN
D
EN
2
GND2
V
CC1
GND1
IN
A
IN
B
OUT
C
OUT
D
EN
1
GND1
1
2
3
4
5
6
7
8
ISO7242
16
15
14
13
12
11
10
9
V
CC2
GND2
OUT
A
OUT
B
IN
C
IN
D
EN
2
GND2
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2007, Texas Instruments Incorporated
TI [ TEXAS INSTRUMENTS ]
