SCD4485 Rev F
FEATURES
❑Radiation Performance
- Total dose > 100 krad (Si)
❑Designed for RS485 and RS422 Interface Applications
❑Single +5V supply
❑+5V to -7V Bus common mode range source output
❑Driver maintains high impedance in three-state or with the power off
❑Combined Impedance of a driver output and receiver allows up to 32 transceivers on the bus
❑200 mV typical input hysteresis
❑Serial data rate 500KHz maximum
❑Voltage source output
❑Receiver output Hi for VIN Diff = 0V
❑< 5ns skew between BUS and BUSN complementary outputs
❑0.63"sq. x 0.125"ht, 18 lead, hermetic flat package
❑Monolithic construction
❑Designed for commercial, industrial and aerospace applications
❑Plainview is a Class H & K MIL-PRF-38534 manufacturer
❑Aeroflex Plainview’s Radiation Hardness Assurance Plan is Certified by DLA Land and Maritime.
GENERAL DESCRIPTION
The Aeroflex-Plainview DRS4485 is a monolithic dual bus/line transceiver designed for multipoint data
transmission standard RS485 applicatons. The DRS4485 meets TIA/EIA -485 requirements. The receiver has a
fail-safe feature which guarantees a high output state when the BUS is open or shorted.
DRS4485 Dual RS485 Interface Transceiver
Standard Products
June 1, 2011
Radiation Tolerant
BUS
BUSN
DI
DE
FIGURE 1 – SCHEMATIC
Rx O
UT
Rx E
N
Rx
D
R
V
CC
GND
Channel 1 or 2
www.aeroflex.com/RadHard
2
SCD4485 Rev F 6/1/2011 Aeroflex Plainview
ABSOLUTE MAXIMUM RATINGS
Operating Case Temperature -55•C to +125•C
Storage Case Temperature -65•C to +150•C
Power Supply Voltages (VCC) +12VDC
Control Input Voltage -0.5 VDC to Vcc + 0.5VDC
Driver Input Voltage -0.5 VDC to Vcc + 0.5VDC
Driver Output Voltage ±5V
Receiver Input Voltage ±5V
Receiver Output Voltages -0.5 VDC to Vcc + 0.5VDC
ELECTRICAL CHARACTERISTICS 1/ 2/
Parameter Condition Symbol Min Typ Max Unit
Differential driver output voltage (unloaded) IO = 0 VOD1 2.5 3.0 5 Vp-p
Differential driver output voltage (with load)
See Figure 2
VOD2 2.5 3.0 5 Vp-p
Change in magnitude of driver differential
output Voltage for complementary states ΔVOD - - 0.2 Vp-p
Driver common mode output voltage VOC -2.553 V
Change in magnitude of driver
common-mode output Voltage for
complementary states
Δ|VOC --0.2V
Input high voltage
DE, DI, RE
VIH 2.4 - - V
Input low voltage VIL -0.8V
Input current IIN ±1 ±2 µA
Differential input threshold voltage for
receiver -6.5V ≤VCM ≤+5V VTH -0.5 -0.2 -0.1 V
Receiver input hysteresis 3/VCM = 0 ΔVTH - 160 400 mV
Receiver output high voltage IO = -0.4mA VOH 4.0 - - V
Receiver output low voltage IO = 0.4mA VOL --0.5V
Receiver input differential resistance 3/-
RINDIFF 30K - - Ω
Receiver input common-mode resistance 3/- RINCM 8K - - Ω
Driver short-circuit current - IOS 50 80 140 mA
Receiver short-circuit current V
OH to GND or VOL to Vcc IOSR 75085mA
STATIC DC POWER SUPPLY CURRENTS
Input
Conditions
Driver Output
Conditions Sym Min Typ Max Unit
Channel Conditions
Channel 1 Channel 2
DE DI RE Output
State
Output
Load Driver Receiver Driver Receiver
0V X 5V HiZ XICC1 -1016
mA Disabled Disabled Disabled Disabled
5V X 0V LoZ NL ICC2 -2940
mA Enabled Enabled Disabled Disabled
5V X 0V LoZ 60 ΩICC3 -5065
mA Enabled Enabled Disabled Disabled
DE=Driver En, DI=Driver In, RE=Receiver En X=HiLo. 0V=GND. 5V=VDC. HiZ=high impedance. LoZ=low impedance. NL=No Load
3
SCD4485 Rev F 6/1/2011 Aeroflex Plainview
SWITCHING CHARACTERISTICS 1/ 2/
Parameter Condition Symbol Min Typ Max Unit
Driver input to output delay
RDIFF = 60Ω
See test ckt
Figure 2
tPLH - 125 200 nS
Driver input to output delay tPHL - 80 150 nS
Driver output to output delay tSKEW -415 nS
Driver rise or fall time tr, tf- 100 150 nS
Driver Output enable delay tZH - 160 250 nS
Driver Output disable delay tLZ - 220 350 nS
Receiver input to output delay
IO = 0
See test ckt
Figure 2
CL = 15pF
tPLH - 80 150 nS
tPHL - 90 150 nS
Receiver rise or fall time tr, tf-2650 nS
Receiver enable delay tZL - 90 150 nS
Receiver disable delay tZH - 120 150 nS
Notes:
1. Min/Max values are for VCC = +5V ±5%, TC = -55°C to +125°C. Typical values are measured at VCC = +5V and TC = +25•C.
2. Current measurements are for both channels.
3. Not tested, guaranteed by design to the specified limits.
DRIVER FUNCTION TABLE
Inputs Outputs
DI DE BUS BUSN
HH/OPENH L
LH/OPENL H
X L OFF HiZ OFF HiZ
RECEIVER FUNCTION TABLE
DIFF Input RE Output
> -100mV L H
< -500mV L L
XH/OPENH
OPEN X H
SHORT X H
+
–
R
R
BUS
BUSN
DI
DE
Voc
VODIFF CDIFF
CSHLD
CSHLD
RX OUT
CL
RE
IOUT
FIGURE 2 – DRIVER/RECEIVER TIMING TEST CIRCUIT (Channel 1 or 2)
15pF
1500pF
1500pF
200pF
30Ω
30Ω
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SCD4485 Rev F 6/1/2011 Aeroflex Plainview
FIGURE 3 – DRIVER SWITCHING WAVEFORMS
FIGURE 3A – TYPICAL DRIVER OUTPUTS
DI
DI
3V
1.5V
t
PLH
t
r
t
SKEW
1/2 V
O
V
OC
80%
10%
0V
V
BUSN
V
BUS
V
O
–V
O
0V, VO
DIFF
90%
1.5V
t
PHL
t
SKEW
1/2 V
O
20%
t
f
VO
DIFF
= V
BUS
– V
BUSN
V
BUS
V
BUSN
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SCD4485 Rev F 6/1/2011 Aeroflex Plainview
FIGURE 4 – RECEIVER SWITCHING WAVEFORMS
FIGURE 4A – TYPICAL RECEIVER OUTPUTS
1.5V
t
PHL
–V
OD2
0V
1.5V
t
PLH
V
OD2
V
OL
V
OH
Rx Out
0V, VO
DIFF
VO
DIFF
6
SCD4485 Rev F 6/1/2011 Aeroflex Plainview
4X R.020
DRS4485
88379
9
1018
MADE IN THE USA
Pin # Function Pin # Function
1 DRIVER ENABLE 1 10 VCC
2 RECEIVER ENABLE 1 11 GROUND
3 RECEIVER OUT 1 12 BUS 2
4 CASE_GND 13 BUSN 2
5 DRIVER IN 1 14 DRIVER IN 2
6 BUSN 1 15 NC_GND
7 BUS 1 16 RECEIVER OUT 2
8 GROUND 17 RECEIVER ENABLE 2
9 VCC 18 DRIVER ENABLE 2
PIN # vs FUNCTION TABLE
PACKAGE CONFIGURATION OUTLINE
7
PLAINVIEW, NEW YORK
Toll Free: 800-THE-1553
Fax: 516-694-6715
SE AND MID-ATLANTIC
Tel: 321-951-4164
Fax: 321-951-4254
INTERNATIONAL
Tel: 805-778-9229
Fax: 805-778-1980
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Tel: 949-362-2260
Fax: 949-362-2266
NORTHEAST
Tel: 603-888-3975
Fax: 603-888-4585
CENTRAL
Tel: 719-594-8017
Fax: 719-594-8468
www.aeroflex.com info-ams@aeroflex.com
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attributes represented by the se three icons :
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Aeroflex Microelectronic Solutions reserves the right to
change at any time without notice the specifications, design,
function, or form of its products described herein. All
parameters must be validated for each customer's application
by engineering. No liability is assumed as a result of use of
this product. No patent licenses are implied.
SCD4485 Rev F 6/1/2011
EXPORT CONTROL: EXPOR T WARNING:
This product is controlled for export under the International Traffic in
Arms Regulations (ITAR). A license from the U.S. Department of
State is required prior to the export of this product from the United
States.
Aeroflex’s military and space products are controlled for export under
the International Traffic in Arms Regulations (ITAR) and may not be
sold or proposed or offered for sale to certain countries. (See ITAR
126.1 for complete information.)
ORDERING INFORMATION
Model DSCC SMD # Screening Case
DRS4485-7 Commercial Flow, +25°C testing only
Flat Pack
DRS4485-S - Military Temperature, -55°C to +125°C
Screened in accordance with the individual Test Meth ods
of MIL-STD-883 for Space Applications
DRS4485-201-1S
DRS4485-201-2S
5962-0922601KXC
5962-0922601KXA In accordance with DSCC SMD
