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From : Andrew A. Kovalyov 2:5077/3.7 Птн 14 Фев 97 21:45
To : Dmitry Dolzhenko Вск 16 Фев 97 06:20
Subj : Шинные преобразователи уровня
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Здравствуйте Вам, Dmitry !
DD> Подскажите как правильно подключить субж 1488 и 1489. А то сколько
DD> схем столько и способов.
А так и включать. Самые обычные буфеpа, без хитpостей. Вот кусочек инфы.
Hадеюсь, она будет понятна...
=== Cut ===
1488, 75188
TTL to RS232 level shifter.
The outputs are at RS-232 levels, and sometimes are connected to ground
through a small capacitor (up to 470 pF) to reduce slew-rate.
Note that 1B is missing (and can be taken to be 1 at all times).
Usually VDD=+12 and VEE=-12.
+----------+ +-------------+
VEE |1 +--+ 14| VDD | A | B | Y |
1A |2 13| 4A |---+---+-----|
1Y |3 12| 4B | 0 | 0 | VDD |
2A |4 1488 11| 4Y | 0 | 1 | VDD |
2B |5 10| 3A | 1 | 0 | VDD |
2Y |6 9| 3B | 1 | 1 | VEE |
GND |7 8| 3Y +-------------+
+----------+
1489, 75189
RS232 to TTL level shifter.
A inputs are RS232-level inputs, C inputs are response control, a TTL
signal which could be used to adjust threshhold and hysteresis but is
generally unnecessary and unused. It is often tied through a 300 - 470 pF
capacitor to ground.
+----------+
1A |1 +--+ 14| VCC
1C |2 13| 4A
1Y |3 12| 4C
2A |4 1489 11| 4Y
2C |5 10| 3A
2Y |6 9| 3C
GND |7 8| 3Y
+----------+
=== Cut ===
Спи спокойно, Dmitry.
* Origin: ---═══< AK Laboratory >═══--- (2:5077/3.7)
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