PIC16F876A-E/SS Microchip Technology, PIC16F876A-E/SS Datasheet - Page 477

• Manufacturer Part Number: PIC16F876A-E/SS
• Description: 28 PIN, 14KB ENH FLASH, 368 RAM, 22 I/O,
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F876A-E/SS

• Rohs Compliant: YES
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Size: 14KB (8K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 368 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 5x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 28-SSOP
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 368 B
• Interface Type: I2C, SPI, USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 22
• Number Of Timers: 1 x 16 bit
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DM163022, DV164120
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 5 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

1997 Microchip Technology Inc.
Note:
COM0 - SEGx [ON] =
COM0 - SEGx [OFF] =
V
V
D = V
Refer to Figure 25-6
RMS
RMS
V
[ON] =
[OFF] =
RMS
RMS
[ON]
[OFF]
The next example is for Figure 25-6 which is a 1/4 MUX, 1/3 BIAS waveform. For this example,
the values 3, 2, 1 and 0 will be assigned to V
DC voltage, RMS voltage and discrimination ratio calculations are shown in
Example 25-4:
As shown in these examples, static displays have excellent contrast. The higher the multiplex
ratio of the LCD, the lower the discrimination ratio, and therefore, the lower the contrast of the
display.
Table 25-5
and BIAS.
As the multiplex of the LCD panel increases, the discrimination ratio decreases. The contrast of
the panel will also decrease, so to provide better contrast the LCD voltages must be increased
to provide greater separation between each level.
Table 25-5: Discrimination Ratio vs. MUX and Bias
1/2 MUX
1/3 MUX
1/4 MUX
STATIC
V
V
= 3
shows the V
1
3 - 3 + 1 - 1 + 1 - 1 + 1 - 1
1 - 1 - 1 + 1 - 1 + 1 - 1 + 1
(1)
(3)
2
2
V
V
Discrimination Ratio Calculation 1/4 MUX
+ (-1)
+ (-3)
0.333
0.333
0.333
V
= 1.732
OFF
0
OFF
2
2
+ (-1)
+ (1)
, V
ON
2
1/3 BIAS
2
+ (-1)
and discrimination ratios of the various combinations of MUX
0.745
0.638
0.577
+ (1)
V
1
ON
2
2
8
8
+ (-1)
+ (1)
3
2
2.236
1.915
1.732
, V
2
+ (-1)
D
+ (1)
2
, V
V
V
DC
DC
1
Section 25. LCD
2
2
, and V
+ (-1)
= 0
= 0
+ (1)
2
2
0
+ (-1)
+ (1)
respectively. The frame equation,
2
2
=
DS31025A-page 25-19
=
Example
3
V
V
25-4.
25