PCA9600D NXP [NXP Semiconductors], PCA9600D Datasheet - Page 19

• Manufacturer Part Number: PCA9600D
• Description: Dual bidirectional bus buffer
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
PCA9600_4
Product data sheet
testing but it was not damaged. Whenever there is current flowing in any of these diodes it
is possible that there can be faulty operation of any IC. For that reason we put a
specification on the negative voltage that is allowed to be applied. It is selected so that, at
the highest allowed junction temperature, there will be a big safety factor that guarantees
the diode will not conduct and then we do not need to make any 100 % production tests to
guarantee the published specification.
For the PCA9600, in specific applications, there will always be transient overshoot and
ringing on the wiring that can cause these diodes to conduct. Therefore we designed the
IC to withstand those transients and as a part of the qualification procedure we made
tests, using DC currents to more than twice the normal bus sink currents, to be sure that
the IC was not affected by those currents. For example, the TX/TY and RX/RY pins were
tested to at least 80 mA which, from
functioning of the PCA9600 is not affected even by those large currents. The Absolute
Maximum (DC) ratings are not intended to apply to transients but to steady state
conditions. This explains why you will never see any problems in practice even if, during
transients, more than 0.3 V is applied to the bus interface pins of PCA9600.
Figure 22 “Diode characteristic curve”
DC specification was selected. The current at 25 C is near zero at 0.55 V. The PCA9600
is allowed to operate with +125 C junction and that would cause this diode voltage to
decrease by 100
publish 0.3 V just to have some extra margin.
Remark: You should not be concerned about the transients generated on the wiring by a
PCA9600 in normal applications and that is input to the TX/RX or TY/RY pins of another
PCA9600. Because not all ICs that may be driven by PCA9600 are designed to tolerate
negative transients, in
they can be managed if required.
Fig 22. Diode characteristic curve
2 mV = 200 mV. So for zero current we need to specify 0.35 V and we
diode current
Rev. 04 — 11 November 2009
(mA)
10
Section 10.2.1 “Example with questions and answers”
10
10
10
10
0
1
1
2
3
4
2.0
1.5
Figure
also explains how the general Absolute Maximum
1.0
22, would be more than 0.8 V. The correct
0.5
voltage (V)
002aaf063
Dual bidirectional bus buffer
0
PCA9600
© NXP B.V. 2009. All rights reserved.
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