MM58248

MM58248 High Voltage Display Driver March 1991 MM58248 High Voltage Display Driver General Description The MM58248 is a monolithic MOS integrated circuit utilizing CMOS metal gate low threshold P- and N-channel devices It is available both in 40-pin molded dual-in-line packages or as dice The MM58248 is particularly suited for driving high voltage (60V max) vacuum fluorescent (VF) displays (e g a 5 x 7 dot matrix display) Features Y Y Y Y Y Y Y Y Applications Y Y Y Y Y Y COPSTM or microprocessor-driven display Instrumentation readouts Industrial control indicator Digital clock thermostat counter voltmeter Word processor text displays Automotive dashboards Direct interface to high voltage display Serial data input No external resistors required Wide display power supply operation LSTTL compatible inputs Software compatible with NS display driver family Compatible with alphanumeric or dot matrix displays No load signal required Block Diagram TL F 5599 – 1 FIGURE 1 COPSTM is a trademark of National Semiconductor Corporation C1995 National Semiconductor Corporation TL F 5599 RRD-B30M105 Printed in U S A Absolute Maximum Ratings If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Voltage at Any Input Pin Voltage at Any Display Pin VDD a lVDISl Storage Temperature Power Dissipation at a 25 C Molded DIP Package Board Mount Molded DIP Package Socket Mount VDD a 0 3V to VSS b 0 3V VDD to VDD b 62 5V 62 5V b 65 C to a 150 C 2 28W 2 05W Junction Temperature Lead Temperature (Soldering 10 seconds) 130 C 260 C Operating Conditions Min Supply Voltage (VDD) VSS e 0V Display Voltage (VDIS) Temperature Range 45 b 55 b 40 Max 55 b 25 a 85 Units V V C Molded DIP Package Board Mount iJA e 46 C W Derate 21 7 mW C above a 25 C Molded DIP Package Socket Mount iJA e 51 C W Derate 19 6 mW C above a 25 C DC Electrical Characteristics TA e b40 C to a 85 C VDD e 5V g 0 5V VSS e 0V unless otherwise specified Symbol IDD IDIS VIL VIH IIN CIN ROFF Input Logic Levels DATA IN CLOCK Logic ‘0’ Input Logic Levels DATA IN CLOCK Logic ‘1’ Input Currents DATA IN CLOCK Input Capacitance DATA IN CLOCK Display Output Impedances Output Off (Figure 3a) VDD e 5 5V VSS e 0V VDIS e b25V VDIS e b40V VDIS e b55V VDD e 5 5V VSS e 0V VDIS e b25V VDIS e b40V VDIS e b55V VDD e 5 5V IOUT e Open Circuit b 55V s VDIS s b 25V IOUT e b 400 mA TTL VOH e 2 4V IOUT e b 400 mA Parameter Power Supply Currents Conditions VIN e VSS or VDD VSS e 0V VDIS Disconnected VDD e 5 5V VSS e 0V VDIS e b55V All Outputs Low Min Typ Max 150 10 08 Units mA mA V V (Note 1) VIN e 0V or VDD 24 b 10 10 15 mA pF kX kX kX kX kX kX V 60 70 80 30 26 23 VDIS 400 550 650 40 37 34 VDIS a 4 RON Display Output Impedances Output on (Figure 3b) VDOL Display Output Low Voltage Note 1 74LSTTL VOH e 2 7V AC Electrical Characteristics TA e b40 C to a 85 C Symbol fC tH tL tDS tDH Parameter Clock Input Frequency Clock Input High Time Clock Input Low Time Data Input Setup Time Data Input Hold Time CL e 50 pF Conditions (Notes 2 3) VDD e 5V g 0 5V Min Typ Max 10 300 300 100 100 Units MHz ns ns ns ns Note 2 AC input waveform specification for test purposes tr tf s 20 ns f e 1 MHz 50% g 10% duty cycle Note 3 Clock input rise and fall times must not exceed 5 ms 2 Connection Diagrams Dual-In-Line Package Plastic Chip Carrier TL F 5599 – 2 Top View Order Number MM58248N See NS Package Number N40A TL F 5599 – 8 Top View Order Number MM58248V See NS Package Number V44A FIGURE 2 Functional Description This product is specifically designed to drive multiplexed or non-multiplexed high voltage alphanumeric or dot matrix vacuum fluorescent (VF) displays Character generation is done externally in the microprocessor with a serial data path to the display driver The MM58248 uses two signals DATA IN and CLOCK with a format of a leading ‘1’ followed by the 35 data bits hence allowing data transfer without an additional signal A block diagram of the MM58248 is shown in Figure 1 Figure 2 shows the pinout of the MM58248 device where output 1 (pin 18) is equivalent to bit 1 i e the first bit of data to be loaded into the shift register following the start bit A logic ‘1’ at the input will turn on the corresponding display digit segment dot output A significant reduction in discrete board components can be achieved by the use of the MM58248 because external pull-down resistors are not required Due to the nature of the output stage both its on and off impedance values vary as a function of the display voltage applied However Figures 3a and 3b show that this output impedance will remain constant for a fixed value of display voltage In Figure 5 a start bit of logic ‘1’ precedes the 35 bits of data each bit being accepted on the rising edge of CLOCK i e a ‘0’ – ‘1’ transition At the 36th clock a LOAD signal is generated synchronously with the high state of the clock thus loading the 35 bits of the shift register into the latches At the low state of the clock a RESET signal is generated clearing all bits of the shift register for the next set of data Hence a complete set of 36 clock pulses is needed for the MM58248 or the shift register will not clear To clear (reset) the display driver at ‘power on’ or any time the following flushing routine may be used Clock in 36 ‘‘zeroes’’ followed by a ‘‘one’’ (start bit) followed by 35 ‘‘zeroes’’ This procedure will completely blank the display It is recommended to clear the driver at power on Figure 4 demonstrates the critical timing requirements between CLOCK and DATA IN for the MM58248 Figure 6 shows a schematic diagram of a microprocessorbased system where the MM58248 is used to provide the anode drive for a 32-digit 5 x 7 dot matrix vacuum fluorescent (VF) display The grid drive in this example is provided by another member of the high voltage display driver family namely the MM58241 which has the additional features of a BLANKING CONTROL pin a DATA OUT pin and an ENABLE (external load signal) pin 3 Functional Description (Continued) TL F 5599 – 3 FIGURE 3a Output Impedance Off TL F 5599 – 4 FIGURE 3b Output Impedance On Timing Diagrams For the purposes of AC measurement VIH e 2 4V VIL e 0 8V TL F 5599 – 5 FIGURE 4 Clock and Data Timings TL F 5599 – 6 FIGURE 5 MM58248 Timings (Data Format) 4 Typical Applications TL F 5599 – 7 FIGURE 6 Microprocessor-Controlled Word Processor Physical Dimensions inches (millimeters) Molded Dual-In-Line Package (N) Order Number MM58248N NS Package Number N40A 5 MM58248 High Voltage Display Driver Physical Dimensions inches (millimeters) (Continued) Plastic Chip Carrier (V) Order Number MM58248V NS Package Number V44A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION As used herein 1 Life support devices or systems are devices or systems which (a) are intended for surgical implant into the body or (b) support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in a significant injury to the user National Semiconductor Corporation 1111 West Bardin Road Arlington TX 76017 Tel 1(800) 272-9959 Fax 1(800) 737-7018 2 A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness National Semiconductor Europe Fax (a49) 0-180-530 85 86 Email cnjwge tevm2 nsc com Deutsch Tel (a49) 0-180-530 85 85 English Tel (a49) 0-180-532 78 32 Fran ais Tel (a49) 0-180-532 93 58 Italiano Tel (a49) 0-180-534 16 80 National Semiconductor Hong Kong Ltd 13th Floor Straight Block Ocean Centre 5 Canton Rd Tsimshatsui Kowloon Hong Kong Tel (852) 2737-1600 Fax (852) 2736-9960 National Semiconductor Japan Ltd Tel 81-043-299-2309 Fax 81-043-299-2408 National does not assume any responsibility for use of any circuitry described no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications