SLLS216A - MAY 1995 - REVISED JANUARY 1996
LocalTalk and AppleTalk are trademarks of Apple Computer, Inc. LinBiCMOS is a trademark of Texas Instruments Incorporated.
The SN75LBC775 is a low-power LinBiCMOSTM device that incorporates the drivers and receivers for an AppleTalk or a LocalTalk interface and a switched-capacitor voltage converter for a single 5-V supply operation. LocalTalk uses a hybrid of RS-422 with the transceiver connected to the network through a small isolation transformer. The AppleTalk mode provides point-to-point communications and uses the same differential driver and receiver as LocalTalk with the addition of a hybrid RS-423, single-ended handshake driver (HSK) and receiver. In the AppleTalk mode, the port connects directly to the receiver with no isolation transformer.
While the device power is turned off (VCC = 0) or disabled in the LocalTalk mode, the outputs are in a high-impedance state. When the driver enable (DEN\) terminal is high, both the differential and serial driver outputs are in a high-impedance state.
The receiver output can be disabled and becomes a high impedance when the REN terminal is low.
A switched-capacitor voltage converter generates the negative voltage required from a single 5-V supply using two 22-uF capacitors. One capacitor is between the C+ and C- terminals and the second is between VSS and ground.
The SN75LBC775 is characterized for operating over the temperature range of 0°C to 70°C.
View more information about generic part numbers:SN75LBC775
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