PIC12C672-10/SM Microchip Technology, PIC12C672-10/SM Datasheet - Page 478

• Manufacturer Part Number: PIC12C672-10/SM
• Description: IC MCU OTP 2KX14 A/D 8-SOIJ
• Manufacturer: Microchip Technology
• Series: PIC® 12Cr

Specifications of PIC12C672-10/SM

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 10MHz
• Peripherals: POR, WDT
• Number Of I /o: 5
• Program Memory Size: 3.5KB (2K x 14)
• Program Memory Type: OTP
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 4x8b
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 8-SOIC (5.3mm Width), 8-SOP, 8-SOEIAJ
• For Use With: XLT08SO-1 - SOCKET TRANSITION 8SOIC 150/208AC164312 - MODULE SKT FOR PM3 16SOICISPICR1 - ADAPTER IN-CIRCUIT PROGRAMMING309-1048 - ADAPTER 8-SOIC TO 8-DIP309-1047 - ADAPTER 8-SOIC TO 8-DIPAC124001 - MODULE SKT PROMATEII 8DIP/SOIC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Connectivity: -
• Other names: PIC12C672-10/SMR; PIC12C672-10/SMR

PICmicro MID-RANGE MCU FAMILY
25.11
DS31025A-page 25-20
LCD Voltage Generation
Among the many ways to generate LCD voltage, two methods stand out above the crowd:
• resistor ladder
• charge pump.
The resistor ladder method, shown in
ages. This method uses inexpensive resistors to create the multi-level LCD voltages. Regardless
of the number of pixels that are energized the current remains constant. The voltage at point V3
is typically tied to V
The resistance values are determined by two factors: display quality and power consumption.
Display quality is a function of the LCD drive waveforms. Since the LCD panel is a capacitive
load, the waveform is distorted due to the charging and discharging currents. This distortion can
be reduced by decreasing the value of resistance. However, this change increases the power
consumption due to the increased current now flowing through the resistors. As the LCD panel
increases in size, the resistance value must be decreased to maintain the image quality of the
display.
Sometimes the addition of parallel capacitors to the resistance can reduce the distortion caused
by charging/discharging currents. The capacitors act as charge storage to provide current as the
display waveform transitions. In general, R is 1 k
200 k .
Figure 25-10: Resistor Ladder
Figure 25-11: Resistor Ladder with Capacitors
CC
, either internally or externally.
Figure
V
V
V
V
3
2
1
0
25-10, is most commonly used for higher V
V
V
V
V
3
2
1
0
+5V
to 50 k
R
R
R
and the potentiometer is 5 k
R
R
R
C
C
C
1997 Microchip Technology Inc.
CC
volt-
to