UM10729
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© NXP Semiconductors B.V. 2017. All rights reserved.
User manual
Rev. 2 — 1 August 2017
9 of 24
NXP Semiconductors
UM10729
PCA9955A/B demonstration board OM13483
Table 1.
Jumper settings for test and evaluation
Jumper
Default setting Comment
J1
(3-pin)
1-2
(V
DD
= +5 V)
This jumper is used to select V
DD
for PCA9955A/B.
1-2:
5 V
2-3:
3.3 V
J2
(3
2-pin)
1-2
(REXT = 1 k
,
57 mA at max.)
This 3
2 jumper is used to select REXT (pin 1) value for PCA9955A/B.
1-2:
select REXT = 1 k
and maximum output current is 57.3 mA
3-4:
select REXT = 1.5 k
and maximum output current is 38.25 mA
5-6:
select REXT = 2 k
and maximum output current is 28.6 mA
J3
(2-pin)
Short
Short:
external 1.1 k
pull-up resistor for SDA on PCA9955A/B.
Open:
no external pull-up resistor for SDA on PCA9955A/B.
Remark:
No external pull-up resistor required for PCU9955A.
J4
(2-pin)
Short
Short:
external 1.1 k
pull-up resistor for SCL on PCA9955A/B.
Open:
no external pull-up resistor for SCL on PCA9955A/B.
Remark:
No external pull-up resistor required for PCU9955A.
J5
(2-pin)
Short
Short:
connect V
DD
(pin 28) to PCA9955A/B.
Open:
connect current meter to measure the I
DD
on PCA9955A/B.
J6
(2-pin)
Open
Short:
force RESET (pin 25) to GND.
Open:
10 k
pull-up RESET (pin 25) to V
DD
.
J7
(4
2-pin)
This 4
2 jumper is used to select quinary input value for AD0 (pin 2).
Open:
floating
1-2:
select V
DD
3-4:
select pull-up with 31.6 k
5-6:
select pull-down with 34.8 k
7-8:
select GND
J8
(3-pin)
1-2
This jumper is used to select bus mode.
1-2:
select normal I
2
C or SPI addressable bus mode
2-3:
select SPI daisy-chain bus mode
J9
(5
2-pin)
This 5
2 jumper is used to select quinary input value for AD1 (pin 3).
Open:
floating
1-2:
select V
DD
3-4:
select pull-up with 31.6 k
5-6:
select pull-down with 34.8 k
7-8:
select GND
9-10:
SDO (Serial Data Out) for SPI addressable mode or last slave device in SPI
daisy-chain
J10
(5
2-pin)
This 5
2 jumper is used to select quinary input value for AD2 (pin 4).
Open:
floating
1-2:
select V
DD
3-4:
select pull-up with 31.6 k
5-6:
select pull-down with 34.8 k
7-8:
select GND
9-10:
CSN (Chip Select) for SPI bus mode
J11
(2-pin)
Short
Short:
force OE (pin 5) to GND, to enable LEDs output.
Open:
10 k
pull-up OE (pin 5) to V
DD
when applying external clock for blinking/dimming on
TP4 (test point).