80x126 pixel LCD driving technology based on PCF8811 design

This article introduces the main features and advantages of PCF8811, block diagram, and several typical application block diagrams.
PCF8811 is a low-power 80x126 pixel CMOS LCD controller from NXP, with 80 rows and 128 columns of output, display data RAM 80x128 bits, 8-bit parallel interface, 3/4-way SPI and high-speed I2C bus, suitable for battery-powered systems, mainly used in automotive displays, communication equipment, portable meters and POS terminals.

PCF8811: 80 x 128 pixels matrix LCD driver

The PCF8811 is a low-power CMOS1 LCD controller and driver, designed to drive a graphic display of 80 rows and 128 columns or a graphic display of 79 rows and 128 columns and an icon row of 128 symbols. All necessary functions for the display are provided in a single chip, including on-chip generation of the LCD supply and bias voltages, resulting in a minimum of external components and low power consumption. The PCF8811 can interface microcontrollers via a parallel bus, serial bus or I2C-bus interface.

PCF8811 main features and advantages:

Single-chip LCD controller and driver

80 row and 128 column outputs

Display data RAM 80 × 128 bit

128 icons (row 80 can be used for icons in extended command set and when icon rows are enabled)

Low power consumption; suitable for battery operated systems

Interfaces: an 8-bit parallel interface, 3 or 4-line Serial Peripheral Interface (SPI) and High-speed I2C-bus

On-chip:

Configurable voltage multiplier generating LCD supply voltage VLCD; an external VLCD is also possible

Linear temperature compensation of VLCD; 8 programmable temperature coefficients (extended command set); one fixed temperature coefficient which can be set as default by OTP programming (basic command set)

Generation of intermediate LCD bias voltage

Oscillator requires no external components

OTP calibration for VLCD and accurate frame frequency

External reset input pad

External clock input possible

Multiplex rate: 1:16 to 1 :80 in steps of 8 when no icon row is used; with the icon row, steps of 16 can be used

Logic supply voltage range VDD1 to VSS:

1.7 V to 3.3 V

High-voltage multiplier supply voltage range VDD2, VDD3 to VSS:

1.8 V to 3.3 V

Display supply voltage range VLCD to VSS:

3 V to 9 V

Programmable bottom row pads mirroring; for compatibility with both Tape Carrier Packages (TCP) and Chip-On-Glass (COG) applications (extended command set)

Status read, which allows for chip recognition and content checking of some registers

Start address line which allows, for instance, the scrolling of the displayed image

Programmable display RAM pointers for variable display sizes

Slim chip layout, suited for COG applications

Temperature range: Tamb = −40℃ to +85℃

CMOS compatible inputs

PCF8811 applications:

Automotive displays

Telecom equipment

Portable instruments

Point-of-sale terminals


Figure 1. PCF8811 Block Diagram

Figure 2. PCF8811 Application Block Diagram: Internal Charge Pump and Single Supply

Figure 3. PCF8811 application block diagram: internal charge pump and two discrete power supplies (VDD1 and VDD2)

Figure 4. PCF8811 application block diagram: external high voltage