PCF8831 View Datasheet(PDF) - Philips Electronics
Part Name
Description
Manufacturer
PCF8831 Datasheet PDF : 28 Pages
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Philips Semiconductors
STN RGB - 160 output row driver
Preliminary specification
PCF8831
7 FUNCTIONAL DESCRIPTION
7.1 Row driver
The row driver comprises high voltage outputs, level
shifters and logic circuits.
The row driver power supplies are:
• VH for the top level of selecting pulses
• VL for the bottom level of selecting pulses
• VM for the non-selecting level when ROWRES2 = HIGH;
the non-selecting level goes to VSS when
ROWRES2 = LOW (active)
• VMH is an intermediate auxiliary supply
• VDD and VSS for the logic circuits.
7.2 80-bit shift register
Two shift registers of 80 bits each are contained in the
PCF8831 row driver. With ROWRES1, the complete shift
register will be reset at the next rising edge of RCLK. The
two shift registers can be configured for different
applications by row control signals R1F, SW1 and SW2.
7.3 Row control
Row control signals SW1, SW2 and R1F control the shift
direction through the register and the order of the register
(see Fig.2). Some switching combinations require the
order of one or both shift registers to be swapped as
shown by the example in Fig.3. All row control
combinations are shown in Table 1, these can be software
controlled when connected to the corresponding row
control signals of the PCF8832 column driver.
ndbook, full pagewidth
LCD ROW OUTPUTS
R0
R79
LCD ROW OUTPUTS
R80
R159
SW1
SW2
R1F
SW1 SW2
00
01
10
11
SHIFT REGISTER 1
SHIFT DIRECTION
SW1
SW2
R1F
SHIFT REGISTER 2
SHIFT DIRECTION
Fig.2 Shift directions; R1F = 1.
MGW630
handbook, full pagewidth
LCD ROW OUTPUTS
R79
R0
LCD ROW OUTPUTS
R159
R80
SW1
SW2
R1F
SHIFT REGISTER 1
SW1
SW2
R1F
SHIFT REGISTER 2
MGW631
Fig.3 Row swapping; SW1 = SW2 = 1.
2002 Aug 14
6
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