NXP Semiconductors PCA9846PW-ARD, User Manual, Page: 9 / 27

NXP Semiconductors
UM11759
PCA9846PW-ARD evaluation board
Ref Des Test point / jumper label Description
TP5 SDA-ARD I
2
C SDA line, Arduino port
TP7 SCL-ARD I
2
C SCL line, Arduino port
TP9 3V3 VCC_3V3 rail
TP10 5V0 VCC_5V0 rail
TP11 3V3_MAIN VCC_3V3_MAIN rail
TP12 5V0_MAIN VCC_5V0_MAIN rail
TP13 LDOOUT1 VCC_LDOOUT1 rail
TP15 GND Ground
TP16 GND Ground
TP17 SDA-CH2 I
2
C SDA line, channel 2
TP18 SCL-CH2 I
2
C SCL line, channel 2
TP19 SDA-CH3 I
2
C SDA line, channel 3
TP20 SCL-CH3 I
2
C SCL line, channel 3
TP21 SDA-CH4 I
2
C SDA line, channel 4
TP22 SCL-CH4 I
2
C SCL line, channel 4
TP23 1V8 VCC_1V8 rail
TP24 2V5 VCC_2V5 rail
TP25 3V6 VCC_3V6 rail
Table 3. PCA9846PW-ARD test points
...continued
4.2.3 I
2
C bus switch/repeater
Figure 3 shows the PCA9846 I
2
C-bus switch/repeater (U11) section. From the Arduino
port, the I
2
C (SDA, SCL) lines go to the DUT through the level translator PCA9617A (U7).
The level shifter U7 assures the separation between the logic level of the Arduino port
(3.3 V) and the selected logic level of the PCA9846 (VCC_LDOOUT1). The I
2
C interface
of U11 is pin 14 for SCL, and pin 15 for SDA. The I
2
C-bus pullup resistors are R56 and
R57. The pin 3 of the DUT is RESET input (active low), and is driven by the onboard
switch SW1. SW1 resets the internal state machine of PCA9846, meaning all channels
are deselected. The address pins A0 and A1 are controlled by the jumper headers
J12 and J13. Refer to PCA9846 data sheet
[1]
for more details about the hardware
address selection. The default selected address is “00”, which corresponds to 0xE2h
for the 8-bit I
2
C-bus address. The VDD1 pin (logic level power supply) is connected to
VCC_LDOOUT1 (the programmable voltage regulator), and the VDD2 pin (core logic
power supply) is connected to VCC_1V8 voltage rail, provided by the LDO regulator U15.
UM11759 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2022. All rights reserved.
User manual Rev. 1 — 6 June 2022
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