Datasheet: SD3502

DSH12206-13 | 1/2018

21

IR TRANSMITTER

As an IR Transmitter, the controller generates and streams a data modulated carrier via a GPIO port to an external IR LED driver,

or via up to 3 GPIO’s (16mA/pin) directly to an IR LED unit.

Figure 21: SD3502 with IR transmitter and receiver devices

Data is kept in a compact pre-scaled format and fetched from SRAM using DMA.

IR RECEIVE/LEARN

The controller listens via GPIO port P3.1 for signals received via an external IR Receiver device or circuit as shown in Figure 21.

The status is made available to the application via polling and via the interrupt system.

Incoming pre-scaled ‘base-band’ data is streamed into SRAM using DMA, and the carrier properties will be acquired in IR Learn

Mode.

LED CONTROLLER

A 4 channel PWM generator is fitted on GPIO port 0 pins 4 to 7. This hardware setup makes it easy to enable control and

dimming of your 4 channels current controlled LED supply via any Z-Wave home control network. Basic operation as well as

detailed fine tuning is available via the API.

Parameter

Value

Description

Pulse width resolution

16 bit

Frequency

488 Hz

No Channels

1-4

Pulse turn-on placement method Normal mode

All pulses start at the beginning of the period.

Skewed mode

Channels are started individually. Delay between starts

equals 25% of a period.

Pins

Port 0 pins 4-7

5 volt compliant 16mA GPIO drivers

KEYPAD SCANNER

The chip includes a key scanner to service up to 88 keys. 11 GPIO outputs and 8 GPIO inputs provide all the pull-up resistors and

Schmitt trigger inputs required by the full setup.

Parameter

Value/Description

Key array size

8 rows by 11 columns.

Number of concurrent key

press detections

Min 2, up to 8.

SD3502/IR

P3.4/IRTX0

P3.5/IRTX1

P3.1/IRRX

P3.6/IRTX2

IR LED

R

IR Receiver

OUT