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SP481E_07 Datasheet, PDF (4/11 Pages) Sipex Corporation – Enhanced Low Power Half-Duplex RS-485 Transceivers | |||
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RO 1
R
8 VCC
RE 2
7B
DE 3
6A
D
DI 4
SP485 5 GND
Top View
SP481E and SP485E
Pinout (Top View)
PIN FUNCTION
Pin 1 â RO â Receiver Output.
Pin 2 â RE â Receiver Output Enable Active LOW.
Pin 3 â DE â Driver Output Enable Active HIGH.
Pin 4 â DI â Driver Input.
Pin 5 â GND â Ground Connection.
Pin 6 â A â Driver Output/Receiver Input
Non-inverting.
Pin 7 â B â Driver Output/Receiver Input Inverting.
Pin 8 â Vcc â Positive Supply 4.75V<Vcc< 5.25V.
A
R
VOD
B
R VOC
Figure 1. RS-485 Driver DC Test Load Circuit
Receiver Test Point
Output
CRL
S1
1k
1k
VCC
S2
Figure 2. Receiver Timing Test Load Circuit
DI
A RDICFFL1
A
RO
B
B
CL2
15pF
Output
500
S1
VCC
Under
Test
CL
S2
Figure 3. RS-485 Driver/Receiver Timing Test Circuit Figure 4. RS-485 Driver Timing Test Load #2 Circuit
+3V
DI
0V
B
DRIVER
OUTPUT A
DIFFERENTIAL VO+
OUTPUT 0V
VA â VB VOâ
tSKEW = | tDPLH - tDPHL |
f = 1MHz; tR < 10ns; tF < 10ns
1.5V
tPLH
tPHL
VO 1/2VO
tDPLH
tDPHL
tR
1.5V
1/2VO
tF
Figure 5. Driver Propagation Delays
May11-2007
SP481E Low Power Half-Duplex RS485 Transceivers
4
© 2007 Sipex Corporation
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