CP2400AB Silicon Laboratories Inc, CP2400AB Datasheet - Page 85

• Manufacturer Part Number: CP2400AB
• Description: BOARD EVAL SPI LCD DRIVER CP2400
• Manufacturer: Silicon Laboratories Inc

Specifications of CP2400AB

• Main Purpose: LCD Development
• Embedded: No
• Utilized Ic / Part: CP2400
• Primary Attributes: I²C, SMBus Interfaces
• Secondary Attributes: Up to 128 segments
• Product: Microcontroller Accessories
• Core Processor: CP2400
• Clock Speed: 20 MHz
• Interface Type: SPI
• Timers: 2
• Operating Supply Voltage: 1.8 V to 3.6 V
• Cpu Core: CP2400
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant
• Other names: 336-1857

12.3. LCD Bias Generation and Contrast Adjustment
The LCD Bias voltages are generated using the on-chip charge pump with programmable output voltage. The
programmable output voltage allows software contrast control in 60 mV steps from 2.6 to 3.44 V. The LCD contrast
is controlled by the CONTRAST register.
Note: An external 4.7 µF decoupling capacitor is required (10 µF recommended) on the CAP pin to create a charge reservoir
Intermediate voltages used for 1/2 and 3/4 bias configurations are generated on-chip using a novel approach that
allows driving extra large LCD segments while maintaining ultra low power consumption. This eliminates the need
for off-chip biasing when driving a large LCD. The LCD drive capability can be set using the LCD0PWR register.
The highest power setting should be used for extra large LCDs (which require charging the largest capacitance)
and the lowest power setting should be used with small LCDs (smaller than 1 inch).
SFR Definition 12.2. CONTRAST: Contrast Adjustment
Address = 0x96
Name
Reset
Type
7:4
3:0
Bit
Bit
at the output of the charge pump.
CNTRST Contrast Adjustment.
Unused
Name
R/W
7
0
Read = 0000. Write = Don’t Care.
Selects the on-chip charge pump output voltage.
0000: 2.60 V
0001: 2.60 V
0010: 2.66 V
0011: 2.72 V
0100: 2.78 V
0101: 2.84 V
0110: 2.90 V
0111: 2.96 V
1000: 3.02 V
1001: 3.08 V
1010: 3.14 V
1011: 3.20 V
1100: 3.26 V
1101: 3.32 V
1110: 3.38 V
1111: 3.44 V
R/W
6
0
R/W
5
0
Rev. 1.0
R/W
4
0
Function
3
0
2
0
CNTRST
CP2400/1/2/3
R/W
1
0
0
0
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