TMC2084-HT Standard Microsystems (SMSC), TMC2084-HT Datasheet - Page 67

• Manufacturer Part Number: TMC2084-HT
• Manufacturer: Standard Microsystems (SMSC)

Specifications of TMC2084-HT

• Number Of Transceivers: 1
• Operating Supply Voltage (max): 3.6V
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (min): 3V
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Compliant

Standalone Mode CircLink
Datasheet
4.1.5
SMSC TMC2084
Case Where Port A and B are Unused
Although both port A (PA7 - 0) and port B (PB7 - 0) are output-only ports, input buffers exist to send
(feedback) the states of the OUTPUT PORT to the host node. The OUTPUT PORT remains in its high-
impedance (floating) state during both reset (nRESET = Low) and the period from de-assertion of reset
(nRESET = High) to the first OUTPUT DATA packet received. Thus, the input node of the input buffer may
be placed in the open state (undefined) during the high-impedance state. This can cause a punch-through
current through the input buffer. To avoid this, either a pull-up or a pull-down resister should be added
externally to each pin of both ports A and B so that each added resister can define the input sate of the
corresponding input buffer during the high-impedance state.
Either a pull-up or a pull-down resister is required externally connected to each pin of both unused ports A
and B as described above.
TM
PA7, PB7
PA6, PB6
PA5, PB5
PA4, PB4
PA3, PB3
PA2, PB2
PA1, PB1
PA0, PB0
Controller
N o pul l - up/dow n r es i st er causes
t he i nput i t s open st at e dur i ng
H i - Z st at e.
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O ut put Buf f er
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DATASHEET
I nput buf f er
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Page 67
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←
←
PAD7-0
PB7-0
A pull-up or pull-
down resister is
needed for each pin.
A pull-up or pull-
down resister is
needed for each pin.
H
L
Revision 0.2 (10-23-08)