Transformer Driver for
Isolated RS-485 Interface
__________________Pin Configuration
TOP VIEW
+
D1 1
GND1 2
FS 3
MAX253
SD 4
8 D2
7 GND2
6 VCC
5 N.C.
DIP/SO/μMAX
_____________________Pin Description
PIN NAME
1
D1
2 GND1
3
FS
4
SD
5
N.C.
6
VCC
7 GND2
8
D2
FUNCTION
Open drain of N-channel transformer drive 1.
Ground. Connect both GND1 and GND2
to ground.
Frequency switch. If FS = VCC or open,
switch frequency = 350kHz; if VFS = 0V,
switch frequency = 200kHz.
Shutdown. Ground for normal operation,
connect high for shutdown.
Not internally connected.
5V supply voltage.
Ground. Connect both GND1 and GND2
to ground.
Open drain of N-channel transformer drive 2.
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