MPR084Q Freescale Semiconductor, MPR084Q Datasheet - Page 5

• Manufacturer Part Number: MPR084Q
• Description: IC CTLR TOUCH SENSOR PROX 16-QFN
• Manufacturer: Freescale Semiconductor
• Type: Capacitiver

Specifications of MPR084Q

• Number Of Inputs/keys: 8 Key
• Data Interface: I²C, Serial
• Voltage - Supply: 1.8 V ~ 3.6 V
• Current - Supply: 1.62mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-QFN Exposed Pad
• Output Type: Voltage
• Interface: I²C
• Input Type: Logic
• Supply Voltage: 3.3 V
• Dimensions: 5 mm L x 5 mm W x 1 mm H
• Supply Current: 41µA
• Ic Interface Type: I2C
• Supply Voltage Range: 1.8V To 3.6V
• Sensor Case Style: QFN
• No. Of Pins: 16
• Operating Temperature Range: -40°C To +85°C
• Filter Terminals: SMD
• Rohs Compliant: Yes
• For Use With: KITMPR084EVM - KIT EVAL 8-PAD TOUCH MPR084
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Sensors
Freescale Semiconductor
The remaining 5 connections are SCL, SDA, IRQ, ATTN, and SOUNDER. Depending on the specific application, each of these
control lines can be used by connecting them to a host system. In the most minimal system, the SCL and SDA must be connected
to a master I
in
Note that in this configuration the AD0 address line is tied high thus the slave address of the MPR084 0x5D. Alternatively the
address line can be pulled low if the host system needs the MPR084 to be on address 0x5C. This functionality can also be used
to incorporate two MPR084 devices in the same system.
2.3
The MPR084 uses an I
Sensor Controller are detailed in the following sections.
2.3.1
The MPR084 operates as a slave that sends and receives data through an I
line (SDA) and a serial clock line (SCL) to achieve bi-directional communication between master(s) and slave(s). A master
(typically a microcontroller) initiates all data transfers to and from the MPR084, and generates the SCL clock that synchronizes
the data transfer.
The MPR084 SDA line operates as both an input and an open-drain output. A pull-up resistor, typically 4.7k, is required on SDA.
The MPR084 SCL line operates only as an input. A pull-up resistor, typically 4.7k, is required on SCL if there are multiple
masters on the 2-wire interface, or if the master in a single-master system has an open-drain SCL output.
Each transmission consists of a START condition
R/W bit, a register address byte, one or more data bytes, and finally a STOP condition.
Figure
Serial Interface
Serial-Addressing
4.
SDA
SCL
t HD STA
2
C interface to communicate with the MPR084. All of the connections for the MPR084 are shown by the schematic
V DD
GND
1μF
CONDIT ION
V DD
ST ART
4.7k Ω
2
C Serial Interface. The I
ATTN
IRQ
SCL
SDA
SOUNDER
t LOW
Figure 4. Recommended System Connections Schematic
t R
t HIGH
1
2
3
4
5
6
7
8
t SU DAT
ATTN
IRQ
VDD
VSS
SCL
SDA
AD0
SOUNDER
Figure 5. Wire Serial Interface Timing Details
MPR084
t F
t HD DAT
2
C protocol implementation and the specifics of communicating with the Touch
(Figure
E1
E2
E3
E4
E5
E6
E7
E8
V DD
16
15
14
13
12
11
10
9
5) sent by a master, followed by the MPR084’s 7-bit slave address plus
t SU STA
780k Ω
REPEAT ED ST ART
780k Ω
CONDIT ION
780k Ω 780k Ω 780k Ω
2
C 2-wire interface. The interface uses a serial data
t HD STA
t SU STO
780k Ω 780k Ω 780k Ω
GND
CONDIT ION
ST OP
ELECTRODE
1
2
3
4
5
6
7
8
9
t BUF
8-TOUCH
ARRAY
E1
E2
E3
E4
E5
E6
E7
E8
GND
PAD
CONDIT ION
ST ART
MPR084
5