SSD1859 Solomon Systech, SSD1859 Datasheet - Page 17

• Manufacturer Part Number: SSD1859
• Description: 128 x 80 STN LCD Segment / Common 4 G/S Drive
• Manufacturer: Solomon Systech

1. 3X, 4X, 5X and 6X DC-DC voltage converter
2. Bias Divider
3. Contrast Control
4. Bias Ratio Selection circuitry
5. Self adjust temperature compensation circuitry
Oscillator Circuit
This module is an On -Chip low power RC oscillator circuitry (Figure 5). The oscillator generates the
clock for the DC-DC voltage converter. This clock is also used in the Display Timing Generator.
LCD Driving Voltage Generator and Regulator
This module generates the LCD voltage needed for display output. It takes a single supply input and
generates necessary bias voltages. It consists of:
It consists of:
209 Bit Latch
A register carries the display signal information. In 128X81 display mode, data will be fed to the HV-
buffer Cell and level-shifted to the required level.
Level Selector
Level Selector is a control of the display synchronization.
Display voltage can be separated into two sets and used with different cycles. Synchronization is
important since it selects the required LCD voltage level to the HV Buffer Cell, which in turn outputs the
COM or SEG LCD waveform.
SSD1859
If the output op-amp buffer option in Set Power Control Register command is enabled, this circuit
block will divide the regulator output (V
The divider does not require external capacitors to reduce the external hardware and pin counts.
Software control of 64 voltage levels of LCD voltage.
Software control of 1/4 to 1/10 bias ratio to match the characteristic of LCD panel.
Provide 2 different compensation grade selections to satisfy the various liquid crystal temperature
grades. The grading can be selected by software control. Defaulted temperature coefficient (TC)
value is -0.05%/°C.
Rev 1.0
OSC1
P 17/48 Dec 2003
Internal resistor
Oscillation Circuit
Figure 5 - Oscillator Circuitry
Internal resistor
out
) to give the LCD driving levels (V
enable
OSC2
enable
Buffer
Oscillator
enable
L2
- V
(CL)
L5
).
Solomon Systech
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