SSD1811 View Datasheet(PDF) - Solomon Systech

Part Name

Description

Manufacturer

SSD1811

LCD Segment / Common Driver with Controller

Solomon Systech  

Oscillator Circuit

This module is an On-Chip low power RC oscillator circuitry (Figure 4). The oscillator generates the clock for the DC-DC

voltage converter. This clock is also used in the Display Timing Generator.

enable

Oscillation Circuit

Oscillator enable

(CLS)

enable

Buffer

(CL)

OSC1

Internal resistor

OSC2

Figure 4 Oscillator Circuitry

LCD Driving Voltage Generator and Regulator

This module generates the LCD voltage required for

display driving output. With reference to VDD, it takes a sin-

gle supply input, VSS, and generate necessary voltage lev-

els. This block consists of:

1. 2X, 3X and 4X DC-DC voltage converter

The built-in DC-DC voltage converter is used to gener-

ate the large negative voltage supply with reference to VDD

from the voltage input (VSS1). For every SSD181X mem-

ber, it is possible to produce 2X, 3X or 4X boosting from the

potential different between VSS1 - VDD.

Detail configurations of the DC-DC converter for differ-

ent boosting multiples are given in Figure 5.

2. Voltage Regulator (Voltages referenced to VDD)

The feedback gain control for LCD driving contrast

curves can be selected by IRS pin to either internal (IRS pin

= H) or external (IRS pin = L).

If internal resistor network is enabled, eight settings

can be selected through software command.

If external control is selected, external resistors are re-

quired to be connected between VDD and VF (R1), and be-

tween VF and VL6 (R2). See application circuit diagrams for

detail connections.

SOLOMON

VSS1 VEE

SSD181X Series

C3N C1P C1N C2P C2N

+

+

C1

C1

2X Boosting Configuration

VSS1 VEE

SSD181X Series

C3N C1P C1N C2P C2N

+

+

+

C1

C1

C1

3X Boosting Configuration

VSS1 VEE

SSD181X Series

C3N C1P C1N C2P C2N

+

++

+

C1

C1 C1

C1

4X Boosting Configuration

Remarks:

1. C1 = 0.47 - 1.0uF

2. Boosting input from V SS1.

3. VSS1 should be lower potential than or equal to VSS

4. All voltages are referenced to V DD

Figure 5 DC-DC Converter Configurations

Rev 3.1

08/2001

SSD181X Series

12

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