CAP1214 datasheet(25/107 Pages) MICROCHIP

25 / 107 page

Multiple Channel Capacitive Touch Sensor and LED Driver

Datasheet

SMSC CAP1214

Revision 1.0 (08-30-10)

DATASHEET

5.2

RESET Pin

The RESET pin is an active high reset that is driven from an external source. The pin contains an

internal delay timer (tRST_FILT) that will block errant glitches on the RESET pin. The RESET pin must

be driven high or low longer than this time before the CAP1214 will react to the pin state.

While the RESET pin is held high, all the internal blocks will be held in reset including the SMBus. All

configuration settings will be reset to default states and all readings will be cleared. Furthermore, the

device will be held in Deep Sleep that can only be removed by driving the RESET pin low.

Once the RESET pin is pulled low, the CAP1214 will begin operation as if a power-on-reset had

occurred. When this happens, the RESET bit will be set and an interrupt will be generated.

5.3

LED Drivers

The CAP1214 contains eleven (11) LED Drivers. Each LED Driver is controlled independently of the

others. LED drivers 1 - 8 can be configured to operate with either push-pull or open-drain drive (see

Section 6.44, "LED / GPIO Output Type Register") and may also be configured to operate as GPIOs

(see Section 6.43, "LED / GPIO Direction Register"). LED drivers 9 - 11 will only operate as open-drain

drivers.

LEDs 1 - 7 and 9 and 10 may be linked to the corresponding Capacitive Touch Sensor input (see

Section 6.50, "Sensor LED Linking Register") so they can be actuated by a touch. When not linked to

sensor inputs, LEDs can be actuated by the host (see Section 6.46, "LED Output Control Registers").

When actuated, the LED drivers operate using one of the following behaviors (see Section 6.51, "LED

Behavior Registers"):

1. Direct - The LED is configured to be on or off when the corresponding input stimulus is on or off

(or inverted). The brightness of the LED can be programmed from full off to full on (default).

Additionally, the LED contains controls to individually configure ramping on, off, and turn-off delay.

2. Pulse 1 - The LED is configured to “Pulse” (transition ON-OFF-ON) a programmable number of

times with programmable rate and min / max brightness. The LED can be configured to be actuated

upon a touch detection (or when hosts sets drive bit) or release detection (or when host clears

drive bit) (see Section 6.52, "LED Pulse 1 Period Register").

3. Pulse 2 - The LED is configured to “Pulse” while actuated and then “Pulse” a programmable

number of times with programmable rate and min / max brightness when the sensor is released.

4. Breathe - The LED is configured to transition ON-OFF-ON (i.e. to “Breathe”) continuously (or with

a programmed off delay) with a programmable rate and min / max brightness.

When an LED is not linked to a sensor and is actuated by the host, there’s an option to assert the

ALERT pin when the LED has completed its behavior (see Section 6.55, "LED Configuration Register").

LED11 operates differently than the other LED outputs in several ways. It is configured to drive up to

two external LED channels simultaneously. It is not automatically disabled during the Sleep or Deep

Sleep states of operation (see Section 6.1, "Main Status Control Register"). It allows for different

behaviors when the device is in Fully Active state versus when the device is in Sleep or Deep Sleep

state. It can drive at a different PWM frequency.

5.3.1

Linking LEDs to Capacitive Touch Sensors

LEDs 1 - 7 can be optionally linked to Capacitive Touch Sensors 1-7 so that when the sensor detects

a button press, the corresponding LED will be actuated at one of the programmed responses.

LEDs 9 and 10 may be optionally linked to the Grouped Sensors to indicate a slide / tap / press and

hold in the “Up” or “Down” directions.

CAP1214 датащи(PDF) 25 Page - Microchip Technology

CAP1214 датащи(HTML) 25 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL