PT6575C LCD Driver IC DESCRIPTION The PT6575C is 1/3 duty and 1/4 duty general-purpose LCD driver that can be used for frequency display in electronic tuners under the control of a microcontroller. The PT6575C can drive an LCD with up to 420 segments directly. The PT6575C can also control up to 8 general-purpose output ports. APPLICATION • Electronic equipment with LCD Display FEATURES • Switching between 1/3 duty and 1/4 duty drive techniques under serial data control. • Switching between 1/2 bias and 1/3 bias drive techniques under serial data control. • Up to 318 segments for 1/3 duty drive and 420 segments for 1/4 duty drive can be displayed. • Serial interface for clock, Data Input, Data Output, Strobe pins. • Serial data control of the power-saving mode based backup function and all the segments forced off function. • Serial data control of switching between the segment output port and the general-purpose output port functions. • Serial data control of frame frequency for common and segment output waveforms. • High generality, since display data is displayed directly without decoder intervention. • Built-in display contrast adjustment circuit • Independent VLCD for the LCD driver block • The /INH pin can force the display to the off state. • RC oscillator circuit BLOCK DIAGRAM Tel: 886-66296288‧Fax: 886-29174598‧ http://www.princeton.com.tw‧2F, 233-1, Baociao Road, Sindian, Taipei 23145, Taiwan PT6575C APPLICATION CIRCUIT Note: *=When a capacitor except the recommended external capacitance (Cosc=1000pF) is connected the OSC pin, we recommend that applications connect the OSC pin with a capacitor in the range 220 to 2200pF. V1.0 2 PT6575C ORDER INFORMATION Valid Part Number PT6575C-TQ Package Type 120 Pins, TQFP Top Code PT6575C-TQ PIN CONFIGURATION V1.0 3 PT6575C PIN DESCRIPTION Pin Name I/O Active Handling when unused S1/P1 to S8/P8 S9 to S105 O - Open COM1 to COM3 COM4/S106 O - Open OSC I/O - VDD I H CE CL DI I GND I - /INH I L GND VLCD0 O - Open VLCD1 I - Open VLCD2 I - Open VDD - - - VLCD - - - VSS - - - V1.0 Function Segment outputs for displaying the display data transferred by serial data input. The pins S1/P1 to S8/P8 can be used as general-purpose output ports when so set up by the control data. Common driver outputs. The frame frequency is fO Hz. The COM4/S106 pin can be used as a segment output in 1/3 duty. Oscillator connection. An oscillator circuit is formed by connecting an external resistor and capacitor to this pin. Serial data transfer inputs. These pins are connected to the control microprocessor. CE: Chip enable CL: Synchronization clock DI: Transfer data Display off control input • /INH=low (VSS)…off S1/P1 to S8/P8=low (VSS) (These pins are forcibly set to the segment output port function and fixed at the VSS level) S9 to S105=low (VSS) COM1 to COM3=low (VSS) COM4/S106=low(Vss) • /INH=high (VDD)…on Note that serial data transfers can be performed when the display is forced off by this pin. LCD Drive 3/3 bias voltage (high level) supply. This level can be modified using the display contrast adjustment circuit. However, note that VLCD0 must be greater than or equal to 2.7V. Also, since this IC provides the built-in display contrast adjustment circuit, applications must not attempt to provide this level from external circuits. LCD drive 2/3 bias voltage (middle level) supply. It is possible to supply the 2/3 VLCD0 voltage to this pin externally. This pin must be shorted to VLCD2 if 1/2 bias is used. LCD drive 1/3 bias voltage (middle level) supply. It is possible to supply the 1/3 VLCD0 voltage to this pin externally. This pin must be shorted to VLCD1 if 1/2 bias is used. Logic block power supply. Provide a voltage in the range 2.7 to 6.0V. LCD driver block power supply. When VLCD0 is between 0.7VLCD and 0.95VLCD, supply a voltage in the range 4.0 to 6.0V. When VLCD0 and VLCD will be equal, supply a voltage in the range 2.7 to 6.0V. Ground pin. Connect to ground. Pin No. 1 to 8 9 to 105 109 to 107 106 116 118 119 120 117 112 113 114 110 111 115 4 PT6575C IMPORTANT NOTICE Princeton Technology Corporation (PTC) reserves the right to make corrections, modifications, enhancements, improvements, and other changes to its products and to discontinue any product without notice at any time. PTC cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a PTC product. No circuit patent licenses are implied. Princeton Technology Corp. 2F, 233-1, Baociao Road, Sindian, Taipei 23145, Taiwan Tel: 886-2-66296288 Fax: 886-2-29174598 http://www.princeton.com.tw V1.0 5