MM58348 High Voltage Display Driver General Description Applications The MM58348 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 MM58348 is particularly suited for driving high voltage (35V max) vacuum fluorescent (VF) displays (e.g., a 5 x 7 dot matrix display). Y Y Y Y Y Y COPSTM or microprocessor-driven displays Instrumentation readouts Industrial control indicator Digital clock, thermostat, counter, voltmeter Word processor text displays Automotive dashboards Features Y Y Y Y Y Y Y Y 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/5601 – 1 FIGURE 1 COPSTM is a trademark of National Semiconductor Corporation. C1995 National Semiconductor Corporation TL/F/5601 RRD-B30M105/Printed in U. S. A. MM58348 High Voltage Display Driver March 1991 Absolute Maximum Ratings Operating Conditions If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications. Supply Voltage (VDD) VSS e 0V Voltage at Any Input Pin Display Voltage (VDIS) Temperature Range Min VDD a 0.3V to VSS b 0.3V VDD to VDD b 36.5V 36.5V b 65§ C to a 150§ C Voltage at Any Display Pin VDD a lVDISl Storage Temperature Power Dissipation at 25§ C Molded DIP Package, Board Mount Molded DIP Package, Socket Mount *Molded DIP Package, Board Mount, Derate 21.7 mW§ C Above 25§ C **Molded DIP Package, Socket Mount, Derate 19.6 mW/§ C Above 25§ C Junction Temperature Lead Temperature (Soldering, 10 seconds) Max Units V V §C 4.5 5.5 b 30 b 10 b 40 a 85 2.28W* 2.05W** iJA e 46§ C/W iJA e 51§ C/W 130§ C 260§ 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 Parameter Power Supply Currents IDIS VIL VIH Conditions Min Input Logic Levels DATA IN, CLOCK Logic ‘0’ Logic ‘1’ IIN Input Currents DATA IN, CLOCK CIN Input Capacitance DATA IN, CLOCK ROFF Display Output Impedances Output Off (Figure 3a) RON Output On (Figure 3b) VDOL Display Output Low Voltage Note 1: 74LSTTL VOH e 2.7V @ Typ VIN e VSS or VDD, VDD e 5.5V, VSS e 0V, VDIS Disconnected VDD e 5.5V, VSS e 0V, VDIS e b30V, All Outputs Low Max Units 150 mA 10 mA 0.8 V 2.4 VIN e 0V or VDD VDD e 5.5V, VSS e 0V VDIS e b10V VDIS e b20V VDIS e b30V VDIS e b10V VDIS e b20V VDIS e b30V @ 10 mA 15 pF 250 300 400 800 750 680 kX kX kX X X X VDIS a 2 V 55 60 65 700 600 500 VDD e 5.5V, IOUT e Open Circuit, b 30V s VDIS s b 10V IOUT e b 400 mA, TTL VOH e 2.4V V b 10 VDIS IOUT e b 400 mA. AC Electrical Characteristic TA e b40§ C to a 85§ C, VDD e 5V g 0.5V Parameter Conditions fC Symbol Clock Input Frequency (Notes 2 and 3 ) Min Typ tH Clock Input High Time 300 ns tL Clock Input Low Time 300 ns tDS Data Input Set-Up Time 100 ns tDH Data Input Hold Time 100 ns Note 2: AC input waveform specification for test purpose: tr s 20 ns, 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 Max Units 1.0 MHz Connection Diagrams Plastic Chip Carrier Dual-In-Line Package TL/F/5601 – 2 Top View TL/F/5601 – 8 FIGURE 2 Top View Order Number MM58348V See NS Package Number V44A Order Number MM58348N See NS Package Number N40A Functional Description 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 use of the MM58348, because external pulldown 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, Figure 3a and 3b show that this output impedance will remain constant for a fixed value of display voltage. 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 MM58348 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 MM58348 is shown in Figure 1. Figure 2 shows the pinout of the MM58348 device, where output 1 (pin 18) is equivalent to bit 1, (i.e., the first bit of TL/F/5601 – 3 FIGURE 3a. Output Impedance Off TL/F/5601 – 4 FIGURE 3b. Output Impedance On 3 Functional Description (Continued) Figure 4 demonstrates the critical timing requirements between CLOCK and DATA IN for the MM58348. 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 to clear (reset) the display driver at ‘‘power on’’ or any time, the following flushing routine may be used. Clock in 36 ‘‘ze- roes’’, 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 6 shows a schematic diagram of a microprocessorbased system where the MM58348 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 MM58341, which has the additional features of a BLANKING CONTROL pin, a DATA OUT pin, and an ENABLE (external load signal) pin. Timing Diagrams TL/F/5601 – 5 For the purpose of AC measurement, VIH e 2.4V, VIL e 0.8V FIGURE 4. Clock and Data Timings TL/F/5601 – 6 FIGURE 5. MM58348 Timings (Data Format) 4 Typical Application TL/F/5601 – 7 FIGURE 6. Microprocessor-Controlled Word Processor Physical Dimensions inches (millimeters) Molded Dual-In-Line Package (N) Order Number MM58348N NS Package Number N40A 5 MM58348 High Voltage Display Driver Physical Dimensions inches (millimeters) (Continued) Plastic Chip Carrier (V) Order Number MM58348V 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. 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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.