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). Applications n n n n COPS™ or microprocessor-driven displays Instrumentation readouts Industrial control indicator Digital clock, thermostat, counter, voltmeter 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 Block Diagram 00792501 FIGURE 1. © 2001 National Semiconductor Corporation DS007925 www.national.com MM58342 High Voltage Display Driver February 1995 MM58342 Absolute Maximum Ratings Molded DIP Package, Socket Mount (Note 1) 1.83W (Note 3) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Junction Temperature 130˚C Lead Temperature (Soldering, 10 sec.) 260˚C Voltage at Any Input Pin Operating Conditions Voltage at Any Display Pin VDD + 0.3V to VSS −0.3V VDD to VDD −36.5V VDD + |VDIS| Electrical Characteristics Symbol Units VSS = 0V 4.5 5.5 V Display Voltage (VDIS) −30 −10 V Temperature Range −40 +85 ˚C −65˚C to +150˚C Power Dissipation at 25˚C Molded DIP Package, Board Mount Max Supply Voltage (VDD) 36.5V Storage Temperature Min 2.03W (Note 2) TA = −40˚C to +85˚C, VDD = 5V ± 0.5V, VSS = 0V unless otherwise specified Parameter Conditions Min Typ Max Units Power Supply Currents IDD VIN = VSS or VDD, VSS = 0V, VDIS Disconnected 150 µA IDIS VDD = 5.5V, VSS = 0V, VDIS = −30V All Outputs Low 10 mA Input Logic Levels DATA IN, CLOCK ENABLE, BLANK VIL Logic “0” VIH Logic “1” 0.8 (Note 4) 2.4 V V Data Output Logic Levels VOL Logic “0” IOUT = 400 µA VOH Logic “1” IOUT = −10 µA VDD −0.5 V 2.8 V 0.4 VOH Logic “1” IOUT = −500 µA IIN Input Currents DATA IN, CLOCK ENABLE, BLANK VIN = 0V or VDD CIN Input Capacitance DATA IN, CLOCK ENABLE, BLANK ROFF RON VDOL −10 V 10 µA 15 pF Display Output Impedances VDD = 5.5V, VSS = 0V Output Off (Figure 3) VDIS = −10V 55 250 kΩ VDIS = −20V 60 300 kΩ VDIS = −30V 65 400 kΩ Output On (Figure 4) Display Output Low Voltage VDIS = −10V 700 800 Ω VDIS = −20V 600 750 Ω VDIS = −30V 500 680 Ω VDIS + 2 V Max Units 800 kHz VDD = 5.5V, IOUT = Open Circuit, −30V ≤ VDIS ≤ −10V AC Electrical Characteristics Symbol TA = −40˚C to +85˚C, VDD = 5V ± 0.5V Parameter Clock Input VDIS Conditions Min Typ (Notes 6, 7) fC Frequency tH High Time 300 ns Low Time 300 ns tL Data Input tDS Set-Up Time 100 ns tDH Hold Time 100 ns www.national.com 2 Symbol TA = −40˚C to +85˚C, VDD = 5V ± 0.5V (Continued) Parameter Enable Input Conditions Min Typ Max Units (Note 5) tES Set-Up Time 100 ns tEH Hold Time 100 ns Data Output tCDO CL = 50 pF 500 Clock Low to Data Out Time ns 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 Plastic Chip Carrier Dual-In-Line Package 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 AC Electrical Characteristics MM58342 Functional Description 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. (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 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: [email protected] www.national.com National Semiconductor Europe Fax: +49 (0) 180-530 85 86 Email: [email protected] 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: [email protected] National Semiconductor Japan Ltd. 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