MPR084Q Freescale Semiconductor, MPR084Q Datasheet - Page 8

• 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

MPR084
8
When performing read-after-write verification, remember to re-set the command byte’s address because the stored command
byte address will generally have been auto-incremented after the write
2.3.8
The application should use repeated starts to address the MPR084 to avoid bus confusion between I
once a master issues a start/repeated start condition, that master owns the bus until a stop condition occurs. If a master that does
not own the bus attempts to take control of that bus, then improper addressing may occur. An address may always be rewritten
to fix this problem. Follow I
2.3.9
The RST is an active-low software reset. This is implemented in the Configuration Register by activating the RST bit. When
asserted, the device clears any transaction to or from the MPR084 on the serial interface and configures the internal registers to
the same state as a power-up reset
The sensor controller is capable of operating down to 1.8 V, however, in order for the sensor controller to exit reset and startup
correctly the host system must initially provide 2.0 V to 3.6 V input to V
is required in applications that require regulated operation in the 1.8 V to 2.0 V range. In the case that the application uses an
unregulated battery, then the battery must initially provide at least 2.0 V to correctly power-up the sensor controller which limits
battery selection to the 2.0 V to 3.6 V range.
S
Operation with Multiple Master
Device Reset
acknowledge from MPR084
How command byte and data byte
SLAVE ADDRESS
map into MPR084's registers
2
C protocol for multiple master configurations.
R/W
Figure 13. Low Voltage (1.8 V - 2.0 V) Power-up Sequence
(Table
1
A
4). The MPR084 then waits for a START condition on the serial interface.
D15 D14 D13 D12 D11 D10 D9 D8
Figure 12. ‘n’ Data Bytes Received
Lower V
COMMAND BYTE
DD
Established Comms with
Apply 2.0V to V
Is Data valid? (0 x 40)
to the desired operating voltage
To Sensor Controller
i.e. Read from FIFO
Sensor Controller?
Idle Delay Loop
1.8 V to 2.0 V
True
acknowledge from
DD
MPR084
Max
DD
(Section
and then follow the process in
False
A
2.4).
D7 D6
D5 D4
DATA BYTE
n bytes
acknowledge from
D3 D2
Freescale Semiconductor
2
C masters.On a I
Figure
auto-increment memory
MPR084
D1 D0
13. This process
word address
A
Sensors
2
C bus,
P