PCA9540B_4

© NXP B.V. 2009. All rights reserved.

Product data sheet

Rev. 04 — 3 September 2009

5 of 22

NXP Semiconductors

PCA9540B

6.3 Power-on reset

lowered below 0.2 V to reset the device.

6.4 Voltage translation

Figure 7 shows the voltage characteristics of the pass gate transistors (note that the graph

was generated using the data specified in Section 10 “Static characteristics” of this

should be equal to, or lower than the lowest bus voltage. For example, if the main bus was

equal to or below 2.7 V to effectively clamp the downstream bus voltages. Looking at

Table 3.

Control register: Write—channel selection; Read—channel status

D7

D6

D5

D4

D3

B2

B1

B0

Command

XXXXX0

XXno channel selected

XXXXX

1

0

0

channel 0 enabled

XXXXX

1

0

1

channel 1 enabled

XXXXX1

1

X

no channel selected

00000000no channel selected;

power-up default state

(1) maximum

(2) typical

(3) minimum

Fig 7.

Pass gate voltage versus supply voltage

2.0

5.5

4.5

3.0

4.0

002aaa964

3.0

2.0

4.0

5.0

(V)

1.0

3.5

5.0

2.5

(1)

(2)

(3)