MM5450

MM5450/5451 Micrel MM5450/5451 LED Display Driver General Description The MM5450 and MM5451 LED display drivers are monolithic MOS IC’s fabricated in an N-Channel, metal-gate process. The technology produces low-threshold, enhancement-mode, and ion-implanted depletion-mode devices. A single pin controls the LED display brightness by setting a reference current through a variable resistor connected to the supply. Features • • • • • • • • Continuous brightness control Serial data input No load signal requirement Enable (on MM5450) Wide power supply operation TTL compatibility 34 or 35 outputs, 15mA capability Alphanumeric capability Applications • • • • Industrial control indicator Relay driver Digital clock, thermometer, counter, voltmeter Instrumentation readouts Ordering Information Part Number MM5450BN MM5451BN MM5450BV MM5451BV Junction Temp. Range –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C Package 40-pin Plastic DIP 40-pin Plastic DIP 44-pin PLCC 44-pin PLCC Block Diagram VDD BRIGHTNESS CONTROL 19 20 OUT 34 24 OUT 1 18 35 OUTPUT BUFFERS 35 LATCHES DATA ENABLE/OUT 35 23 (See Note 1) SERIAL DATA 22 35-BIT SHIFT REGISTERS LOAD RESET CLOCK 21 1 Note 1: Pin 23 is Data Enable in MM5450 Pin 23 is Output 35 in MM5451 Figure 1. RESET (only available in die form) 870 01 Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com May 2000 1 MM5450/5451 MM5450/5451 OUTPUT BIT 13 OUTPUT BIT 14 OUTPUT BIT 15 OUTPUT BIT 16 OUTPUT BIT 17 OUTPUT BIT 18 OUTPUT BIT 19 OUTPUT BIT 20 OUTPUT BIT 21 OUTPUT BIT 22 OUTPUT BIT 23 Micrel Connection Diagram: Die OUTPUT BIT 12 OUTPUT BIT 11 OUTPUT BIT 10 OUTPUT BIT 9 OUTPUT BIT 8 OUTPUT BIT 7 V SS OUTPUT BIT 6 OUTPUT BIT 5 OUTPUT BIT 4 OUTPUT BIT 3 V SS OUTPUT BIT 24 OUTPUT BIT 25 OUTPUT BIT 26 OUTPUT BIT 27 OUTPUT BIT 28 MM5450/5451 DIE PINOUT OUTPUT BIT 29 V SS OUTPUT BIT 30 OUTPUT BIT 31 OUTPUT BIT 32 OUTPUT BIT 33 BRIGHTNESS CONTROL RESET OUTPUT BIT 34 OUTPUT BIT 35 ENABLE DATA CLK V DD OUTPUT BIT 1 OUTPUT BIT 2 Note: Die size is 0.106" x 0.099" Figure 2. Connection Diagram: Dual-in-line Package V SS OUTPUT BIT 17 OUTPUT BIT 16 OUTPUT BIT 15 OUTPUT BIT 14 OUTPUT BIT 13 OUTPUT BIT 12 OUTPUT BIT 11 OUTPUT BIT 10 1 2 3 4 5 6 7 8 9 MM5450BN 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 OUTPUT BIT 18 OUTPUT BIT 19 OUTPUT BIT 20 OUTPUT BIT 21 OUTPUT BIT 22 OUTPUT BIT 23 OUTPUT BIT 24 OUTPUT BIT 25 OUTPUT BIT 26 OUTPUT BIT 27 OUTPUT BIT 28 OUTPUT BIT 29 OUTPUT BIT 30 OUTPUT BIT 31 OUTPUT BIT 32 OUTPUT BIT 33 OUTPUT BIT 34 DATA ENABLE DATA IN CLOCK IN V SS OUTPUT BIT 17 OUTPUT BIT 16 OUTPUT BIT 15 OUTPUT BIT 14 OUTPUT BIT 13 OUTPUT BIT 12 OUTPUT BIT 11 OUTPUT BIT 10 1 2 3 4 5 6 7 8 9 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 OUTPUT BIT 18 OUTPUT BIT 9 10 OUTPUT BIT 8 11 OUTPUT BIT 7 12 OUTPUT BIT 6 13 OUTPUT BIT 5 14 OUTPUT BIT 4 15 OUTPUT BIT 3 16 OUTPUT BIT 2 17 OUTPUT BIT 1 18 BRIGHTNESS 19 CONTROL V DD 20 OUTPUT BIT 9 10 OUTPUT BIT 8 11 OUTPUT BIT 7 12 OUTPUT BIT 6 13 OUTPUT BIT 5 14 OUTPUT BIT 4 15 OUTPUT BIT 3 16 OUTPUT BIT 2 17 OUTPUT BIT 1 18 BRIGHTNESS 19 CONTROL V DD 20 Figure 3a, 3b. MM5450/5451 2 May 2000 MM5450/5451 Micrel Connection Diagram: Plastic Leaded Chip Carrier OUTPUT BIT 18 OUTPUT BIT 19 OUTPUT BIT 20 OUTPUT BIT 21 OUTPUT BIT 14 OUTPUT BIT 15 OUTPUT BIT 16 OUTPUT BIT 17 6 OUTPUT BIT 13 OUTPUT BIT 12 OUTPUT BIT 11 7 8 9 5 4 3 2 1 44 43 42 41 40 39 38 37 36 35 OUTPUT BIT 23 OUTPUT BIT 24 OUTPUT BIT 25 OUTPUT BIT 26 OUTPUT BIT 27 NC OUTPUT BIT 28 OUTPUT BIT 29 OUTPUT BIT 30 OUTPUT BIT 31 OUTPUT BIT 32 OUTPUT BIT 10 10 OUTPUT BIT 9 11 NC 12 OUTPUT BIT 8 13 OUTPUT BIT 7 14 OUTPUT BIT 6 15 OUTPUT BIT 5 16 OUTPUT BIT 4 17 18 OUTPUT BIT 3 MM5450BV OUTPUT BIT 22 V SS NC 34 33 32 31 30 29 19 OUTPUT BIT 2 20 OUTPUT BIT 1 21 BRIGHTNESS CONTROL 22 V DD 23 NC 24 CLOCK IN 25 DATA IN 26 DATA ENABLE 27 OUTPUT BIT 34 OUTPUT BIT 21 28 OUTPUT BIT 33 OUTPUT BIT 18 OUTPUT BIT 19 OUTPUT BIT 20 OUTPUT BIT 14 OUTPUT BIT 15 OUTPUT BIT 16 OUTPUT BIT 17 6 OUTPUT BIT 13 7 8 9 10 11 NC 12 13 14 15 16 17 18 5 4 3 2 1 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 OUTPUT BIT 23 19 20 21 22 24 25 26 27 28 Figure 4a, 4b. May 2000 3 OUTPUT BIT 22 V SS NC MM5450/5451 MM5450/5451 Micrel Absolute Maximum Ratings Voltage (any pin) ...................................... VSS to VSS +12V Power Dissipation (PD) +25°C ......................................................................... 1W +85°C .................................................................. 560mW Junction Temperature (TJ) ...................................... +150°C Storage Temperature (TS) ....................... –65°C to +150°C Lead Temperature (soldering, 10 sec.) ................... +300°C Operating Ratings Supply Voltage (VDD – VSS) ....................... +4.75V to +11V Ambient Temperature Range (TA) ............. –40°C to +85°C Electrical Characteristics 4.5V ≤ VDD ≤ 11V, VSS = 0V; TA = 25°C, bold values indicate –40°C ≤ TA ≤ +85°C; unless noted Symbol Parameter Power Supply Current Data Input Voltage VL VH Brightness Control Input Current Output Sink Current Condition –25°C to +85°C, excluding output loads –40°C to +85°C, excluding output loads logic-0 level, ±10µA input bias logic-1 level, 4.75V ≤ VDD ≤ 5.25V VDD > 5.25V Note 2 segment off, VOUT = 3.0V segment on, VOUT = 1.0V, Note 3 brightness input = 0µA brightness input = 100µA brightness input = 750µA Brightness Control Input Voltage Output Matching fC tH tL tDS tDH tDES Clock Input Frequency Clock Input High Time Clock Input Low Time Data Input Setup Time Data Input Hold Time Data Enable Input Setup Time Reset Pad Current Note 1: Note 2: Note 3: Note 4: Note 5: Note 6: Min Typ Max 8.5 10 Units mA mA V V V mA µA µA mA mA V % kHz ns ns ns ns ns µA –0.3 2.2 VDD–2 0 0.8 VDD VDD 0.75 10 0 2.0 15 3.0 2.7 10 4 25 4.3 input current = 750µA Note 1 Notes 5, 6 Notes 5, 6 Notes 5, 6 ±20 500 950 950 300 300 100 die 8 Output matching is calculated as the percent variation (IMAX + IMIN) ÷ 2. With a fixed resistor on the brightness input pin, some variation in brightness will occur among devices. Maximum brightness control input current can be 2mA providing it complies with Note 3 and the junction temperature equation. See Figures 7, 8 and 9 for recommended operating conditions and limits. Absolute maximum for each output should be limited to 40mA. VOUT should be regulated by the user. See Figures 8 and 9 for allowable VOUT vs. IOUT operation. AC input waveform specification for test purpose: tR ≤ 20ns, tF ≤ 20ns, f = 500kHz, 50% ± 10% duty cycle. Clock input rise and fall times must not exceed 300ns. MM5450/5451 4 May 2000 MM5450/5451 Micrel Functional Description The MM5450 and MM5451 were designed to drive either 4- or 5-digit alphanumeric LED displays with the added benefit of requiring minimal interface with the display or data source. Data is transferred serially via 2 signals; clock and serial data. Data transfer without the added inconvenience of an external load signal is accomplished by using a format of a leading “1” followed by the allowed 35 data bits. These 35 data bits are latched after the 36th has been transferred. This scheme provides non multiplexed, direct drive to the LED display. Characters currently displayed (thus, data output) changes only if the serial data bits differ from those previously transferred. Control of the output current for LED displays provides for the display brightness. To prevent oscillations, a 1nF capacitor should be connected to pin 19, brightness control. The block diagram is shown in Figure 1. For the MIC5450, the DATA ENABLE is a metal option and is used instead of the 35th output. The output current is typically 20-times greater that the current into pin 19, which is set by an external variable resistor. There is an external reset connection shown which is available on unpackaged (die) only. Figure 2 illustrates the die pad locations for bonding in “chip on board” applications. Figure 5 shows the input data format. A leading “1” is followed by 35 bits of data. After the 36th had been transferred, a LOAD signal is generated synchronously with the clock high state. This loads the 35 bits of data into the latches. The low side of the clock is used to generate a RESET signal which clears all shift registers for the next set of data. All shift registers are static master-slave, with no clear for the master portion of the first register, allowing continuous operation. CLOCK There must be a complete set of 36 clocks or the shift registers will not clear. When the chip first powers ON, an internal power ON reset signal is generated which resets all registers and all latches. The START bit and the first clock return the chip to its normal operation. Figure 3 and 4 show the pin-out of the MIC5450 and MIC5451. Bit 1 is the first bit following the start bit and it will appear on pin 18. A logical “1” at the input will turn on the appropriate LED. Figure 5 shows the timing relationships between data, clock and DATA ENABLE. A maximum clock frequency of 0.5MHz is assumed. For applications where a lesser number of outputs are used, it is possible to either increase the current per output, or operate the part at higher than 1V VOUT. The following equation can be used for calculations. TJ = (VOUT) (ILED) (No. of segments) (124°C/W) + TA where: TJ = junction temperature + 150°C max VOUT = the voltage at the LED driver outputs ILED = the LED current 124°C/W = thermal resistance of the package TA = ambient temperature The above equation was used to plot Figures 7–9. DATA 300 nS MIN DATA ENABLE 100 nS MIN Figure 5. 1 CLOCK START BIT 1 DATA BIT 35 BIT 36 36 37 LOAD (INTERNAL) RESET (INTERNAL) Figure 6. Input Data Format May 2000 5 MM5450/5451 MM5450/5451 Micrel Typical Performance Characteristics 110 T A = 85°C 100 90 OUTPUT CURRENT (mA) 2.5 VOUT = 1V TA = 85°C TJ = 150°C (MAX) 2.0 20 SE 80 70 60 50 40 30 20 10 0 0 5 10 15 20 25 30 34 VOUT = 1.5V S 30 VOUT (VO ) 1.5 G M EG M S 34 EG VOUT = 2V M 1.0 0.5 0 0 4 8 12 16 20 24 28 NUMBER OF SEGMENTS ILED (mA) Figure 7. 1.0 34 SEGMENTS VOUT = 1V 15 mA/SEGMENT 0.8 Figure 8. POWER DISSIPATION (W) 0.6 SAFE OPERATING AREA 0.4 0.2 0 0 20 40 60 80 100 TEMPERATURE (°C) Figure 9. Typical Applications RAW DC >9V 7V LM317 240 Ω ∆V – 5k 1k I 19 5V 20 LM324 + ∆V 1K 5V 20 1 2N2907 CD4046 (VCO) PIN 19 MM5450 MM74HC123 10 µS Q 19 MM5450 1 I 19 = Figure 11. Brightness Control Varying the Duty Cycle Figure 10. Typical Application of Constant Current Brightness Control MM5450/5451 6 May 2000 MM5450/5451 Micrel LED DISPLAY AM Typical Applications FM 34 MM5450 DISPLAY DRIVER KEYBOARD ELECTRONIC TUNING CONTROLLER PLL SYNTHESIZER STATION DETECT, ETC. Figure 12. Basic Electronically Tuned Radio System VLED = 3.0V VLED VLED VLED = 3.0V 9–16 2–8, 40 32–39 MM5450 24–31 18 21 22 19 CLOCK IN DATA IN BRIGHTNESS CONTROL 20 1 23 17 VDD 100k TYP. Figure 13. Duplexing 8 Digits with One MM5450. May 2000 7 MM5450/5451 MM5450/5451 Micrel Package Information 2.040 20 1 .100 .546 ±.010 .030 NOM 105°/90° 21 40 .075 .020 MIN .150 .060 ± .002 .125 MIN .625±.025 .010 .080 NOM .018 TYP .100 TYP 40-Pin Plastic DIP (N) TOP VIEW 0.045 0.045 0.050 TYP NON-ACCUM 0.015 0.094 DETAIL A 0.104 0.028 0.018 0.652 0.690 ±0.005 0.062 TYP 0.030 TYP SIDE VIEW BOTTOM VIEW 0.137 TYP 0.045 0.045 0.035 R ±0.010 DETAIL A 0.125 DIA x 0.005 DEEP 4 PLCS (EJECTOR PIN) 0.104 0.172 0.020 MIN 44-Pin PLCC (V) MICREL INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 TEL USA + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB http://www.micrel.com This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc. © 2000 Micrel Incorporated MM5450/5451 8 .610 ±.015 0.062 DIA x 0.020 DEEP May 2000