LC75847T Datasheet, PDF (12/27 Pages) Sanyo Semicon Device – 1/3, 1/4 Duty General-Purpose LCD Driver

LC75847T
Control Data Functions
1. P0 to P3: Segment output port/general-purpose output port switching control data.
These control data bits switch the S1/P1 to S8/P8 output pins between their segment output port and general-
purpose output port functions.
Control data
P0
P1
P2
P3
0
0
0
0
0
0
0
1
0
0
1
0
0
0
1
1
0
1
0
0
0
1
0
1
0
1
1
0
0
1
1
1
1
0
0
0
S1/P1
S1
P1
P1
P1
P1
P1
P1
P1
P1
S2/P2
S2
S2
P2
P2
P2
P2
P2
P2
P2
Note: Sn (n = 1 to 8): Segment output ports
Pn (n = 1 to 8): General-purpose output ports
S3/P3
S3
S3
S3
P3
P3
P3
P3
P3
P3
Output pin state
S4/P4 S5/P5
S4
S5
S4
S5
S4
S5
S4
S5
P4
S5
P4
P5
P4
P5
P4
P5
P4
P5
S6/P6
S6
S6
S6
S6
S6
S6
P6
P6
P6
S7/P7
S7
S7
S7
S7
S7
S7
S7
P7
P7
S8/P8
S8
S8
S8
S8
S8
S8
S8
S8
P8
Also note that when the general-purpose output port function is selected, the output pins and the display data will
have the correspondences listed in the tables below.
Output pin
S1/P1
S2/P2
S3/P3
S4/P4
S5/P5
S6/P6
S7/P7
S8/P8
Corresponding display data
1/3 duty
1/4 duty
D1
D1
D4
D5
D7
D9
D10
D13
D13
D17
D16
D21
D19
D25
D22
D29
For example, when 1/4 duty drive scheme is used, if the general-purpose output port function is selected for the
S4/P4 output pin, that output pin will output a high level (V_LCD) when the display data D13 is 1, and a low level
(V_SS) when the D13 is 0.
2. CT0 to CT2: Control data that sets the display contrast
This control data is used to set the display contrast.
CT0 to CT2: Display contrast setting (7 steps)
CT0 CT1
0
0
1
0
0
1
1
1
0
0
1
0
0
1
CT2
0
0
0
0
1
1
1
LCD drive 3/3 bias voltage power supply (V_LCD0) level
1.00 V_LCD = V_LCD – (0.05 V_LCD × 0)
0.95 V_LCD = V_LCD – (0.05 V_LCD × 1)
0.90 V_LCD = V_LCD – (0.05 V_LCD × 2)
0.85 V_LCD = V_LCD – (0.05 V_LCD × 3)
0.80 V_LCD = V_LCD – (0.05 V_LCD × 4)
0.75 V_LCD = V_LCD – (0.05 V_LCD × 5)
0.70 V_LCD = V_LCD – (0.05 V_LCD × 6)
Note that although the display contrast can be adjusted by operating the built-in display contrast adjustment circuit, it
is also possible to adjust the contrast by varying the voltage level on the LCD drive block power supply V_LCD pin.
However, V_LCD0 must always be greater than or equal to 2.7 V.
No. 7389-12/27