Linear Technology LTM2882-3 RS232 µModule Isolator Demo Board (3.3V Supply) DC1554A-A DC1554A-A Datenbogen
Produktcode
DC1554A-A
LTM2882
12
2882fd
Channel Timing Uncertainty
Multiple channels are supported across the isolation bound-
Multiple channels are supported across the isolation bound-
ary by encoding and decoding of the inputs and outputs.
The technique used assigns T1IN/R1IN the highest priority
such that there is no jitter on the associated output chan-
nels T1OUT/R1OUT, only delay. This preemptive scheme
will produce a certain amount of uncertainty on T2IN/
R2IN to T2OUT/R2OUT and DIN to DOUT. The resulting
pulse width uncertainty on these low priority channels is
typically ±6ns, but may vary up to about 40ns.
Half-Duplex Operation
The DE pin serves as a low-latency driver enable for half-
The DE pin serves as a low-latency driver enable for half-
duplex operation. The DE pin can be easily driven from
the logic side by using the uncommitted auxiliary digital
channel, DIN to DOUT. Each driver is enabled and disabled
in less than 2µs, while each receiver remains continuously
active. This mode of operation is illustrated in Figure 6.
applicaTions inForMaTion
Figure 6. Half-Duplex Configuration Using D
OUT
to Drive DE
2882 F06
ON
DIN
T1IN
R1OUT
T2IN
R2OUT
DE
DOUT
T1OUT
R1IN
T2OUT
R2IN
LTM2882
3.3V (LTM2882-3)
5V (LTM2882-5)
V
L
V
CC
V
CC2
GND
GND2
ISOLA
TION BARRIER
T
X
R
X
Driver Overvoltage and Overcurrent Protection
The driver outputs are protected from short-circuits to
The driver outputs are protected from short-circuits to
any voltage within the absolute maximum range of ±15V
relative to GND2. The maximum current is limited to no
more than 70mA to maintain a safe power dissipation and
prevent damaging the LTM2882.
Receiver Overvoltage and Open Circuit
The receiver inputs are protected from common mode
The receiver inputs are protected from common mode
voltages of ±25V relative to GND2.
Each receiver input has a nominal input impedance of 5kΩ
Each receiver input has a nominal input impedance of 5kΩ
relative to GND2. An open circuit condition will generate a
logic high on each receiver’s respective output pin.
RF, Magnetic Field Immunity
The LTM2882 has been independently evaluated and has
The LTM2882 has been independently evaluated and has
successfully passed the RF and magnetic field immunity
testing requirements per European Standard EN 55024,
in accordance with the following test standards:
EN 61000-4-3
EN 61000-4-3
Radiated, Radio-Frequency,
Electromagnetic Field Immunity
EN 61000-4-8
Power Frequency
Magnetic Field Immunity
EN 61000-4-9
Pulsed Magnetic Field Immunity
Tests were performed using an unshielded test card de-
signed per the data sheet PCB layout recommendations.
Specific limits per test are detailed in Table 1.
Table 1
TEST
FREQUENCY
FIELD STRENGTH
EN 61000-4-3, Annex D
80MHz to 1GHz
10V/m
1.4MHz to 2GHz
3V/m
2GHz to 2.7GHz
1V/m
EN 61000-4-8, Level 4
50Hz and 60Hz
30A/m
EN 61000-4-8, Level 5
60Hz
100A/m*
EN 61000-4-9, Level 5
Pulse
1000A/m
*Non IEC Method