MSC5301B-01 Datasheet, PDF (10/15 Pages) OKI electronic componets – LCD COMMON/SEGMENT DRIVER WITH RAM

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MSC5301B-01
• BLK (Pin 37)
This is an input pin to control the LCD panel display.
When a "H" level is input (or when this pin is open), the segment output pins S0 - S63 come to
the levels V₂ - V₃ and the LCD panel is turned off. In addition, during this period, reading of
data from display RAM stops but writing into the display RAM of address and segment data
input from the SI pin is enabled.
When this pin is changed from "H" to "L" level, the frame synchronizing signal FRAM is output
within 2 cycles of an internal clock ff, and multiple chips are synchronized. Then, the display
RAM address is set to "0000". After 1/16 frame cycle from FRAM signal generation, the output
is applied from the "0001" data of the display RAM address to the segment driver. When the
power supply is turned on, keep this pin to "H" level (or leave open) until writing data to the
RAM is completed, because the display RAM contents are undefined at power-on. A pull-up
resistor (10 kW - 60 kW) and a Schmitt circuit are contained.
• POR (Pin 36)
This is a power-on-reset input pin. When a "H" level is input (or when this pin is open), the
common and segment outputs come to the static display-off state regardless of the BLK pin and
the segment output pins S0 - S63 become V₃ level and the common output pins C0 - C15 become
V₄ level.
When this pin changes from "H" to "L" level, the frame synchronizing signal FRAM is output
within 2 cycles of an internal clock ff, synchronized at multichip, and is moreover dynamic-
operated from the frame B . The display RAM address is set to "0000."
After 1/16 frame cycle from FRAM signal generation, the data at display RAM address "0001"
is output to the segment driver. However, because the BLK pin is usually at "H" level when
the power-on-reset is released, reading data from the display RAM stops and display-off
segment data is forcibly transferred to the segment output.
A pull-up resistor (10 kW - 60 kW) and a Schmitt are contained.
• C0 (Pin 12) - C15 (Pin 27)
These are 16-output pins of common driver which are used for LCD panel driving. The outputs
have 4 levels. V_DSP and GND levels are select levels. The V1 and V4 levels are non-select levels.
• S0 (Pin 47) - S63 (Pin 11)
These are 64-output pins of segment driver which are used for LCD panel driving. The outputs
have 4 levels. V_DSP and GND levels are used as display-on ones, which correspond to "1" of
the display RAM data. V₂ and V₃ levels are used as display-off ones, which correspond to "0"
of the display RAM data.
NOTES ON USE
Note the following when turning power on and off:
The LCD drivers of this IC require a high voltage. For this reason, if a high voltage is applied
to the LCD drivers with the logic power supply floating, excess current flows. This may
damage the IC. Be sure to carry out the following power-on and power-off sequences:
When turning power on:
First turn V_CC ON, next V_DSP, V₄, V₃, V₂, V₁ ON. Or both ON at the same time.
When turning power off:
First turn V_DSP, V₄, V₃, V₂, V₁ OFF, next V_CC OFF. Or both OFF at the same time.
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