MM58342

MM58342 High Voltage Display Driver February 1995 MM58342 High Voltage Display Driver General Description The MM58342 is a monolithic MOS integrated circuit utilizing CMOS metal gate low threshold P- and N-channel devices. It is available both in 28-pin molded dual-in-line packages or as dice. The MM58342 is particularly suited for driving high voltage (35V max) vacuum fluorescent (VF) displays (e.g., a 20-digit alphanumeric or dot matrix display). n Word processor text displays n Automotive dashboards Features n n n n n n n n n 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 Display blanking control input Simple to cascade Applications n n n n COPS™ or microprocessor-driven displays Instrumentation readouts Industrial control indicator Digital clock, thermostat, counter, voltmeter Block Diagram 00792501 FIGURE 1. © 2001 National Semiconductor Corporation DS007925 www.national.com MM58342 Absolute Maximum Ratings (Note 1) Molded DIP Package, Socket Mount Junction Temperature Lead Temperature (Soldering, 10 sec.) 1.83W (Note 3) 130˚C 260˚C 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 + |VDIS| Storage Temperature Power Dissipation at 25˚C Molded DIP Package, Board Mount 2.03W (Note 2) VDD + 0.3V to VSS −0.3V VDD to VDD −36.5V 36.5V −65˚C to +150˚C Operating Conditions Min Supply Voltage (VDD) VSS = 0V Display Voltage (VDIS) Temperature Range 4.5 −30 −40 5.5 −10 +85 V V ˚C Max Units Electrical Characteristics Symbol IDD IDIS Input Logic Levels DATA IN, CLOCK ENABLE, BLANK VIL VIH VOL VOH VOH IIN CIN Logic “0” Logic “1” Data Output Logic Levels Logic “0” Logic “1” Logic “1” Input Currents DATA IN, CLOCK ENABLE, BLANK Input Capacitance DATA IN, CLOCK ENABLE, BLANK Display Output Impedances ROFF Output Off (Figure 3) Parameter Power Supply Currents TA = −40˚C to +85˚C, VDD = 5V ± 0.5V, VSS = 0V unless otherwise specified Conditions VIN = VSS or VDD, VSS = 0V, VDIS Disconnected VDD = 5.5V, VSS = 0V, VDIS = −30V All Outputs Low Min Typ Max Units 150 10 µA mA 0.8 (Note 4) IOUT = 400 µA IOUT = −10 µA IOUT = −500 µA VIN = 0V or VDD VDD −0.5 2.8 −10 10 15 VDD = 5.5V, VSS = 0V VDIS = −10V VDIS = −20V VDIS = −30V 55 60 65 700 600 500 VDIS 250 300 400 800 750 680 VDIS + 2 2.4 0.4 V V V V V µA pF kΩ kΩ kΩ Ω Ω Ω V RON Output On (Figure 4) VDIS = −10V VDIS = −20V VDIS = −30V VDOL Display Output Low Voltage VDD = 5.5V, IOUT = Open Circuit, −30V ≤ VDIS ≤ −10V AC Electrical Characteristics Symbol fC tH tL tDS tDH Parameter Clock Input Frequency High Time Low Time Data Input Set-Up Time Hold Time TA = −40˚C to +85˚C, VDD = 5V ± 0.5V Conditions Min Typ Max 800 300 300 100 100 Units kHz ns ns ns ns (Notes 6, 7) www.national.com 2 MM58342 AC Electrical Characteristics Symbol tES tEH tCDO Parameter Enable Input Set-Up Time Hold Time Data Output Clock Low to Data Out Time TA = −40˚C to +85˚C, VDD = 5V ± 0.5V (Continued) Conditions Min 100 100 Typ Max Units ns ns 500 ns (Note 5) CL = 50 pF Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Note 2: Molded DIP Package, Board Mount, θJA = 52˚C/W, derate 19.2 mW/˚C above 25˚C. Note 3: Molded DIP Package, Socket Mount, θJA = 58˚C/W, derate 17.2 mW/˚C above 25˚C. Note 4: 74LSTTL VOH = 2.7V @ IOUT = −400 µA, TTL VOH = 2.4V @ IOUT = −400 µA. Note 5: For timing purposes, the signals ENABLE and BLANK can be considered to be totally independent of each other. Note 6: AC input waveform specification for test purposes: tr, tf ≤ 20 ns, f = 800 kHz, 50% ± 10% duty cycle. Note 7: Clock input rise and fall times must not exceed 5 µs. Connection Diagrams Dual-In-Line Package Plastic Chip Carrier 00792508 Top View Order Number MM58342V See NS Package Number V28B 00792502 Top View Order Number MM58342N See NS Package Number N28B 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 MM58342 uses three signals, DATA IN, CLOCK and ENABLE, where ENABLE acts as an external load signal. Display blanking can be achieved by means of the BLANKING CONTROL input, and a logic “1” will turn off all sections of the display. A block diagram of the MM58342 is shown in Figure 1. FIGURE 2. Figure 2 shows the pinout of the MM58342 device, where output 1 (pin 12) is equivalent to bit 1 (i.e., the first bit of data to be loaded into the shift register following ENABLE high). 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 MM58342, because external 3 www.national.com MM58342 Functional Description (Continued) 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 3, 4 show that this output impedance will remain constant for a fixed value of display voltage. Figure 5 demonstrates the critical timing requirements between CLOCK and DATA IN for the MM58342. To clear (reset) the display driver at power on or any time, the following flushing routine may be used. With the enable signal high, clock in 20 zeroes. Drive the enable signal low and the display will be blank. It is recommended to clear the driver at power on. In Figure 6, the ENABLE signal acts as an envelope, and only while this signal is at a logic “1” does the circuit accept CLOCK input signals. Data is transferred and shifted in the internal shift register on the rising clock edge, i.e., “0”–“1” transition. When the ENABLE signal goes low, the contents of the shift registers are latched, and the display will show new data. During data transfer, the display will show old data. DATA OUT is also provided on the MM58342 being output on the falling edge. At any time, the display may be blanked under processor control, using the BLANKING CONTROL input. Figure 7 shows a schematic diagram of a microprocessor-based system where the MM58342 is used to provide the grid drive for a 40-digit 2 line 5 x 7 multiplexed vacuum fluorescent (VF) display. The anode drive in this example is provided by another member of the high voltage display driver family, namely the MM58348, which does not require an extremely generated load signal. 00792503 FIGURE 3. Output Impedance Off 00792504 FIGURE 4. Output Impedance On Timing Diagrams 00792505 FIGURE 5. Clock and Data Timings www.national.com 4 MM58342 Timing Diagrams (Continued) 00792506 FIGURE 6. Timings (Data Format) Typical Application 00792507 FIGURE 7. Microprocessor-Controlled Word Processor 5 www.national.com MM58342 Physical Dimensions inches (millimeters) unless otherwise noted Molded Dual-In-Line Package (N) Order Number MM58342N NS Package Number N28B www.national.com 6 MM58342 High Voltage Display Driver Physical Dimensions inches (millimeters) unless otherwise noted (Continued) Plastic Chip Carrier (V) Order Number MM58342V NS Package Number V28A 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 AND GENERAL COUNSEL 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 Americas Email: support@nsc.com National Semiconductor Europe Fax: +49 (0) 180-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Français Tel: +33 (0) 1 41 91 8790 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 Asia Pacific Customer Response Group Tel: 65-2544466 Fax: 65-2504466 Email: ap.support@nsc.com National Semiconductor Japan Ltd. Tel: 81-3-5639-7560 Fax: 81-3-5639-7507 www.national.com 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.