± 18K ESD Protection, Full Fail-Safe RS-485 Transceiver
Description
The TP8485E are IEC61000 ESD protected, 3V~5.5V
powered transceivers that meet the RS-485 and RS-422
standards for balanced communication. Driver outputs
and receiver inputs are protected against ±18kV ESD
strikes without latch-up.
Transmitters in this family deliver exceptional differential
output voltages (2.5V min/5Vcc), into the RS-485 required
54Ω load, for better noise immunity, or to allow up to eight
120Ω terminations in “star” topologies. These devices
have very low bus currents so they present a true “1/8 unit
load” to the RS-485 bus. This allows up to 256
transceivers on the network without using repeaters.
Receiver (Rx) inputs feature a “Full Fail-Safe” design,
which ensures a logic high Rx output if Rx inputs are
floating, shorted, or on a terminated but undriven bus. Rx
outputs feature high drive levels - typically 25mA @ VOL
= 1V (to ease the design of optocoupled isolated
interfaces).
The TP8485E is available in an SOIC-8 and MSOP-8
package, and is characterized from –40° to 125°
C
C.
Hot Plug Circuitry - Tx and Rx Outputs Remain
Three-State During Power-up/Power-down
Data Rate: 300 bps to 250 kbps
Full Fail-safe (Open, Short, Terminated)
Receivers
Up to 256 Nodes on a Bus (1/8 unit load)
Wide Supply Voltage 3V to 5.5V
SOIC-8 Package for Backward Compatibility
Bus-Pin Protection:
– ±18 kV HBM protection
– ±13 kV IEC61000-4-2 Contact Discharge
– +4 kV IEC61000-4-4 Fast Transient Burst
Applications
E-Metering Networks
Industrial Automation
HVAC Systems
Process Control
DMX512-Networks
Battery-Powered Applications
3PEAK and the 3PEAK logo are registered trademarks of
3PEAK INCORPORATED. All other trademarks are the property of
their respective owners.
Pin Configuration
(Top View)
TP8485E
8-Pin SOIC/MSOP
-S and -V Suffixes
Exceptional Tx Drives Up To 256 Loads While
Still Delivering 2.5V VOD
100
Driver Output Current (mA)
90
80
+25
℃
70
RD=15Ω
60
50
+85
℃
R
RE
DE
D
1
8
VCC
B/Z
A/Y
GND
2
7
3
6
40
30
20
RD=54Ω
4
5
RD=20Ω
RD=100Ω
10
0
0.5
1
1.5
2
2.5
3
3.5
Differential Output Voltage (V)
www.3peakic.com.cn
Rev. A.01
1
TP8485E
± 18K ESD Protection, Full Fail-Safe RS-485 Transceiver
Order Information
Model Name
TP8485E
TP8485E
Order Number
TP8485E-SR
TP8485E-VR
Package
8-Pin SOIC
8-Pin MSOP
Transport Media, Quantity
Tape and Reel, 4,000
Tape and Reel, 3,000
Marking
Information
TP8485E
TP8485E
DRIVER PIN FUNCTIONS
INPUT
D
ENABLE
DE
OUTPUTS
A
B
NORMAL MODE
H
L
X
X
OPEN
H
H
L
OPEN
H
H
L
Z
Z
H
L
H
Z
Z
L
Actively drives bus High
Actively drives bus Low
Driver disabled
Driver disabled by default
Actively drives bus High
DESCRIPTION
RECEIVER PIN FUNCTIONS
DIFFERENTIAL
INPUT
V
ID
= V
A
– V
B
ENABLE
/RE
OUTPUT
R
NORMAL MODE
V
IT+
< V
ID
V
IT–
< V
ID
< V
IT+
V
ID
< V
IT–
X
X
Open, short, idle Bus
L
L
L
H
OPEN
L
H
?
L
Z
Z
?
Receive valid bus High
Indeterminate bus state
Receive valid bus Low
Receiver disabled
Receiver disabled
Indeterminate bus state
DESCRIPTION
2
Rev. A.01
www.3peakic.com.cn
TP8485E
± 18K ESD Protection, Full Fail-Safe RS-485 Transceiver
Absolute Maximum Ratings
V
DD
to GND.......................................................................................................................................-0.3V to +7V
Input Voltages
DI, DE, RE………………………………………………………………………….…………………….....-0.3V to (VCC + 0.3V)
Input/Output Voltages
A/Y, B/Z, A, B, Y, Z………………………………………………………………………..………………. -15V to +15V
A/Y, B/Z, A, B, Y, Z (Transient Pulse Through 100Ω,