3PEAK
Features
TPT485N
± 18K ESD Protection, Bus-Polarity Correcting RS-485 Transceiver
Description
The TPT485N is a low-power RS-485 transceiver with
automatic bus-polarity correction and transient protection.
Upon hot plug-in, the device detects and corrects the
bus polarity within the first 100 ms of bus idling. On-chip
transient protection protects the device against IEC61000
ESD and EFT transients. This device has robust drivers
and receivers for demanding industrial applications. The
bus pins are robust to electrostatic discharge (ESD)
events, with high levels of protection to Human-Body
Model (HBM), Air-Gap Discharge, and Contact Discharge
specifications. The device combines a differential driver
and a differential receiver, which operate together from a
single 5-V power supply. The driver differential outputs
and the receiver differential inputs are connected
internally to form a bus port suitable for half-duplex
(two-wire bus) communication. The device features a
wide common-mode voltage range making the device
suitable for multi-point applications over long cable runs.
Exceeds Requirements of EIA-485 Standard
Bus-Polarity Correction within 100 ms (t
FS
)
Data Rate: 300 bps to 500 kbps
Works with Two Configurations:
– Failsafe Resistors Only
– Failsafe and Differential Termination Resistors
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
– ±12 kV IEC61000-4-2 Contact Discharge
Applications
E-Metering Networks
HVAC Systems
DMX512-Networks
The TPT485N is available in SOP8 package, and is
characterized from –40° to 125°
C
C.
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)
TP485E
8-Pin SOIC/MSOP
TPT485N
-S and -V Suffixes
Automatic Bus-polarity Correction With/
Without Pull-up and Pull-down Resistor
Vcc
Vcc
R
RE
DE
D
1
8
VCC
B/Z
A/Y
0.1μF
RxD
R
Vcc
2
7
MCU
DIR
RE
DE
D
TP485E
TPT485N
A
B
GND
3
6
TxD
4
5
GND
www.3peakic.com.cn
Rev. 0
1
TPT485N
± 18K ESD Protection, Bus-Polarity Correcting RS-485 Transceiver
Revision History
Date
Revision
Notes
201811/29
2019/04/10
2019/09/08
2019/09/26
Rev. Pre 0
Rev. Pre 0.1
Rev. Pre 0.2
Rev. 0
Initial Definition
Update package information
Update ESD information
Final version
Order Information
Model Name
TPT485N
Order Number
TPT485N-SO1R
Package
8-Pin SOP
Transport Media, Quantity
Tape and Reel
4,000
Marking
Information
T485N
Pin Configuration and Functions
Pin No.
1
2
3
4
5
6
7
8
Pin Name
R
DE
/RE
D
GND
A
B
V
CC
I/O
Digital output
Digital input
Digital input
Digital input
Ground
Bus input/output
Bus input/ouput
Power
Description
Receiver data output.
Driver Enable, active high.
Receiver Enable, active low.
Driver data input.
Ground.
Bus I/O port, A
Bus I/O port, B
Power Supply.
2
Rev. 0
www.3peakic.com.cn
TPT485N
± 18K ESD Protection, Bus-Polarity Correcting RS-485 Transceiver
Function Table
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
POLARITY-CORRECTING MODE
(1)
H
L
X
X
OPEN
(1)
H
H
L
OPEN
H
L
H
Z
Z
L
H
L
Z
Z
H
Actively drives bus Low
Actively drives bus High
Driver disabled
Driver disabled by default
Actively drives bus Low
DESCRIPTION
The polarity-correcting mode is entered when V
ID
< V
IT–
and t > t
FS
and DE = low. This state is latched when /RE turns from Low to
High.
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
H
Receive valid bus High
Indeterminate bus state
Receive valid bus Low
Receiver disabled
Receiver disabled
Out of polarity correction time
POLARITY-CORRECTING MODE
(1)
V
IT+
< V
ID
V
IT–
< V
ID
< V
IT+
V
ID
< V
IT–
X
X
Open, short, idle Bus
(1)
L
L
L
H
OPEN
L
L
?
H
Z
Z
H
Receive valid bus Low
Indeterminate bus state
Receive polarity corrected bus High
Receiver disabled
Receiver disabled
Out of polarity correction time
DESCRIPTION
The polarity-correcting mode is entered when V
ID
< V
IT–
and t > t
FS
and DE = low. This state is latched when /RE turns from Low to
High.
www.3peakic.com.cn
Rev. 0
3
TPT485N
± 18K ESD Protection, Bus-Polarity Correcting 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, B ….......................………………………………………...………………….…... -15V to +15V
A, B (Transient Pulse Through 100Ω,Note 1)……………………………………...………….……….….… ±100V
R……………………………………………………………………………………...…………………….…..…. -0.3V to (VCC +0.3V)
Short Circuit Duration A, B …………………………………………………………………………….…….. Continuous
ESD Rating……………………………………………………………………………………………………..… See Specification Table
Recommended Operating Conditions
Note 2
Supply Voltage………………………………………………………………………………….………..……. 3V to 5.5V
Temperature Range……………………………………………………………………………………...…… -40° to +125°
C
C
Bus Pin Common Mode Voltage Range ……………………………………………………………..…….. -7V to +12V
Thermal Resistance, ΘJA (Typical)
8-Pin SOIC Package ……………………………………………………………….…………………...…… 136°
C/W
Maximum Junction Temperature (Plastic Package) …………………………………………...…………. +150°
C
Maximum Storage Temperature Range ………………………………………………………..………….. -65° to +150°
C
C
Note 1:
Tested according to TIA/EIA-485-A, Section 4.2.6 (±100V for 15μs at a 1% duty cycle).
Note 2:
Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact
product reliability and result in failures not covered by warranty.
ESD Rating
Value
Contact Discharge, per IEC 61000-4-2
Bus Pin
Bus Pin
HBM, per ANSI/ESDA/JEDEC JS-001 / ANSI/ESD STM5.5.1
All Pin Except Bus Pin
CDM, per ANSI/ESDA/JEDEC JS-002
4
1500
kV
V
12
18
Unit
kV
kV
4
Rev. 0
www.3peakic.com.cn
TPT485N
± 18K ESD Protection, Bus-Polarity Correcting RS-485 Transceiver
Electrical Characteristics
Test Conditions: VCC = 5V, Over operating free-air temperature range
Parameter
Conditions
RL = 60 Ω,
-7V≤V test ≤12V
RL = 54 Ω (RS-485)
RL = 100 Ω (RS-485)
See Figure 1B
See Figure 1A
Min
1.5
1.65
2.0
Type
3.3
3.3
4.4
Max
Units
|V
OD
|
Driver differential-output voltage
magnitude
V
⊿|V
OD
|
V
OC(SS)
⊿V
OC
V
OC(PP)
V
IT+
Change in magnitude of driver
differential-output voltage
Steady-stage common-mode
output voltage
Change in differential driver
common-mode output voltage
Peak-to-peak driver common-
mode output voltage
Positive-going receiver differential-
input voltage threshold
Negative-going receiver
differential-input voltage threshold
Receiver differential-input voltage
threshold hysteresis (V
IT
+ – V
IT–
)
Logic Input High Voltage
Logic Input Low Voltage
Receiver high-level output voltage
Receiver low-level output voltage
Driver input, driver enable and
receiver enable input current
Receiver high-impedance output
current
Driver short-circuit output current
Bus input current(driver disabled)
RL = 54 Ω, CL=50pF
See Figure 1A
-50
50
mV
V
1
Center of two 27-Ω
load resistors
See Figure 1A
-50
V
CC
/2
3
50
mV
600
100
mV
V
IT-
-100
mV
V
HYS(1)
V
IH
V
IL
V
OH
V
OL
I
I
30
DI, DE, RE
DI, DE, RE
I
OH
= -8 mA
I
OL
= 8 mA
-5
4.0
0.2
0.4
5
2
0.8
mV
V
V
V
V
μA
μA
mA
μA
I
OZ
|I
OS
|
I
I
VO = 0 V or VCC, /RE at VCC
│I
OS
│ with V
A
or V
B
from –7 to +12 V
V
CC
= 4.5 to 5.5 V or
V
CC
= 0 V, DE at 0 V
Driver and receiver
enabled
Driver enabled,
receiver disabled
VI= 12 V
VI= -7 V
DE = VCC, /RE =
GND, No LOAD
DE = VCC, /RE =
V
CC
, No LOAD
DE = GND, /RE =
V
CC
, No LOAD
DE = GND, /RE =
V
CC
, D= V
cc
No
LOAD
1
95
55
-90
755
85
950
560
750
μA
I
CC
Supply current(quiescent)
Driver disabled,
receiver enabled
Driver and receiver
disabled
550
700
0.1
2
Note: V
IT-
can meet -100mV spec in 25C 5V
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Rev. 0
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