Cypress Semiconductor CY3280-MBR3 データシート

Document Number: 001-85330 Rev. *G 

Page 15 of 37

If the buzzer is not currently active, the buzzer output starts on 

each trigger event. 

■

When the buzzer is enabled, the buzzer output toggles between 

a Logic HIGH state and a Logic LOW state, to drive the buzzer 

when active. When the buzzer is inactive, the buzzer output 

maintains a Logic HIGH state.

■

The buzzer ON Time has a range of (1 to 127) × 100 ms.

This feature generates a pulse signal on any change in the 

CapSense sensors' status.

■

The host interrupt is an active LOW pulse signal generated on 

the HI pin during any change in the sensor status or slider 

position.

■

The duration of the active LOW host interrupt pulse is T

HI

 (refer 

to 

■

The minimum time between two HI pulses is equal to one 

refresh interval.

■

The host interrupt pin has the open-drain low-drive mode.

■

This pin is powered by V

DDIO

 in CY8CMBR3108. This allows 

communication with a host processor at voltage levels lower 

than the chip V

DD

. 

■

Only one pin can be configured as the host interrupt on devices 

that have a host interrupt functionality on multiple pins.

■

Allows to read both current status (CS) and latch status (LS) 

to avoid missing button touches.

■

CS and LS can be read through registers, BUTTON_STAT, and 

LATCHED_BUTTON_STAT respectively.

 explains the various combinations of CS and LS.

Some of the applications use analog voltage as an effective 

method to indicate the sensor status to the host controller. A 

simple external resistor network can be used with GPOs of 

CY8CMBR3xxx to generate analog voltage output upon touch 

detection for such applications. 
The CY8CMBR3xxx GPOs support the open-drain low-drive 

mode. In this mode, the sensor “touch” state is indicated by a 

logic LOW signal on the GPO and a "no touch" state is indicated 

by the HIGH-Z signal. With the external resistor shown in 

, when a sensor is touched, the respective GPO is driven to a 

logic LOW signal. This forms a simple voltage divider and 

produces a voltage output. All the other GPOs are in HIGH-Z 

states because their respective sensors are in the "no touch" 

state. 

The output analog voltage can be calculated based on the 

following equation:

Here, Rn represents the series resistor value of any given GPO.

BUZ

Buzzer ON Tim e

CSx

Sensor 

Activated

Sensor 

Re‐activated

HI

CSx

Sensor 

Activated

T

HI

Sensor 

Deactivated

0

0

CSx is not touched during the current I

2

C read

Host has already acknowledged any previous CSx touch in 

the previous I

2

C read

0

1

CSx was touched before the current I

2

C read

This CSx touch was missed by the host

R

0

GPO0

GPO1

GPO2

GPO3

GPO4

GPO5

GPO6

GPO7

CS0

CS1

CS2

CS3

CS4

CS5

CS6

CS7

R

1

R

2

R

3

R

4

R

5

R

6

R

7

V

OUT

CY8CMBR3xxx

CS0

CS1

CS2

CS3

CS4

CS5

CS6

CS7

R