Rainbow Electronics MAX3033E - Manual (Page 8)

MAX3030E–MAX3033E
Detailed Description
The MAX3030E–MAX3033E are high-speed quad RS-
422 transmitters designed for digital data transmission
over balanced lines. They are designed to meet the
requirements of TIA/EIA-422-B and ITU-T V.11. The
MAX3030E–MAX3033E are available in two pinouts to
be compatible with both the 26LS31 and SN75174
industry-standard devices. Both are offered in 20Mbps
and 2Mbps baud rate. All versions feature a low-static
current consumption (I
CC < 100µA) that makes them
ideal for battery-powered and power-conscious appli-
cations. The 20Mbps version has a maximum propaga-
tion delay of 16ns and a part-to-part skew less than
5ns, allowing these devices to drive parallel data. The
2Mbps version is slew-rate-limited to reduce EMI and
reduce reflections caused by improperly terminated
cables.
Outputs have enhanced ESD protection providing
±15kV tolerance. All parts feature hot-swap capability
that eliminates false transitions on the data cable dur-
ing power-up or hot insertion.
±15kV ESD Protection
As with all Maxim devices, ESD-protection structures
are incorporated on all pins to protect against electro-
static discharges encountered during handling and
assembly. The driver outputs and receiver inputs have
extra protection against static electricity. Maxim’s engi-
neers developed state-of-the-art structures to protect
these pins against ESD of ±15kV without damage. The
ESD structures withstand high ESD in all states: normal
operation and power-down. After an ESD event, the
MAX3030E–MAX3033E keep working without latchup.
ESD protection can be tested in various ways; the
transmitter outputs of this product family are character-
ized for protection to ±15kV using the Human Body
Model. Other ESD test methodologies include
IEC10004-2 Contact Discharge and IEC1000-4-2 Air-
Gap Discharge (formerly IEC801-2).
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results.
Human Body Model
Figure 8 shows the Human Body Model, and Figure 9
shows the current waveform it generates when dis-
charged into low impedance. This model consists of a
100pF capacitor charged to the ESD voltage of interest,
which is then discharged into the test device through a
1.5k
Ω resistor.
±15kV ESD-Protected, 3.3V Quad
RS-422 Transmitters
8 _______________________________________________________________________________________
DI
V CC
GND
A
A
DO_-
DO_+
Figure 7. Power-Off Measurements
Test Circuits and
Timing Diagrams (continued)
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR Cs
100pF
R C
1M Ω
R D
1.5k Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
Figure 8. Human Body ESD Test Model
I
P
100%
90%
36.8%
t RL
TIME
t DL
CURRENT WAVEFORM
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
Ir
10%
0
0
AMPS
Figure 9. Human Body Current Waveform