

4

NXP Semiconductors

33972

PIN CONNECTIONS

PIN CONNECTIONS

Figure 3. 33972 Pin Connections

Table 2. 33972 Pin Definitions

A functional description of each pin can be found in the Functional Pin Description section beginning on page 10.

Pin Number

Pin Name

Pin Function

Formal Name

Definition

1

GND

Ground

Ground

Ground for logic, analog, and switch to battery inputs.

2

SI

Input

SPI Slave In

SPI control data input pin from the MCU to the 33972.

3

SCLK

Input

Serial Clock

SPI control clock input pin.

4

CS

Input

Chip Select

SPI control chip select input pin from the MCU to the 33972. Logic [0}

allows data to be transferred in.

5–8

25–28

SP0–3

SP4–7

Input

Programmable

Switches 0–7

Programmable switch-to-battery or switch-to-ground input pins.

9–15,

18–24

SG0–6,

SG13–7

Input

Switch-to-Ground

Inputs 0–13

Switch-to-ground input pins.

16

VPWR

Input

Battery Input

Battery supply input pin. Pin requires external reverse battery

protection.

17

WAKE

Input/Output

Wake-up

Open drain wake-up output. Designed to control a power supply

enable pin.

29

INT

Input/Output

Interrupt

Open-drain output to MCU. Used to indicate an input switch change of

state.

30

AMUX

Output

Analog Multiplex Output Analog multiplex output.

31

VDD

Input

Voltage Drain Supply

3.3/5.0 V supply. Sets SPI communication level for the SO driver.

32

SO

Output

SPI Slave Out

Provides digital data from the 33972 to the MCU.

EP

Ground

Exposed Pad

It is recommended that the exposed pad is terminated to GND (pin 1)

and system ground, however, the device will perform as specified with

the exposed pad unterminated (floating).

SO

1

SP7

SP6

SP5

SP4

SG7

SG8

SG9

SG10

SG11

SG13

WAKE

SG12

INT

VDD

AMUX

GND

SP0

SP1

SP2

SP3

SG0

SG1

SG2

SG3

SG4

SG6

VPWR

SG5

CS

SI

SCLK

8

9

10

11

12

13

14

15

16

3

4

5

6

7

2

32

25

24

23

22

21

20

19

18

17

30

29

28

27

26

31

Exposed Pad

EK Suffix

Only

SO

1

SP7

SP6

SP5

SP4

SG7

SG8

SG9

SG10

SG11

SG13

WAKE

SG12

INT

VDD

AMUX

GND

SP0

SP1

SP2

SP3

SG0

SG1

SG2

SG3

SG4

SG6

VPWR

SG5

CS

SI

SCLK

8

9

10

11

12

13

14

15

16

3

4

5

6

7

2

32

25

24

23

22

21

20

19

18

17

30

29

28

27

26

31

EW Suffix

EK Suffix