MM5450/5451 Micrel MM5450/5451 LED Display Driver General Description Features 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. 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 Junction Temp. Range Package MM5450BN –40°C to +85°C 40-pin Plastic DIP MM5451BN –40°C to +85°C 40-pin Plastic DIP MM5450BV –40°C to +85°C 44-pin PLCC MM5451BV –40°C to +85°C 44-pin PLCC Block Diagram VDD 20 BRIGHTNESS CONTROL 19 OUT 34 OUT 1 24 18 35 OUTPUT BUFFERS 35 LATCHES LOAD DATA ENABLE/OUT 35 23 (See Note 1) SERIAL DATA 22 35-BIT SHIFT REGISTERS RESET CLOCK 21 1 RESET (only available in die form) 870 01 Note 1: Pin 23 is Data Enable in MM5450 Pin 23 is Output 35 in MM5451 Figure 1. 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 V SS Connection Diagram: Die OUTPUT BIT 18 OUTPUT BIT 19 OUTPUT BIT 20 OUTPUT BIT 21 OUTPUT BIT 22 OUTPUT BIT 23 Micrel OUTPUT BIT 13 OUTPUT BIT 14 OUTPUT BIT 15 OUTPUT BIT 16 OUTPUT BIT 17 MM5450/5451 OUTPUT BIT 12 OUTPUT BIT 24 OUTPUT BIT 25 OUTPUT BIT 26 OUTPUT BIT 11 OUTPUT BIT 10 OUTPUT BIT 27 OUTPUT BIT 28 OUTPUT BIT 9 OUTPUT BIT 8 OUTPUT BIT 7 OUTPUT BIT 29 MM5450/5451 DIE PINOUT V SS V SS OUTPUT BIT 6 OUTPUT BIT 5 OUTPUT BIT 4 OUTPUT BIT 30 OUTPUT BIT 31 OUTPUT BIT 3 OUTPUT BIT 33 OUTPUT BIT 32 OUTPUT BIT 34 OUTPUT BIT 35 ENABLE DATA CLK V DD BRIGHTNESS CONTROL RESET 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 1 40 OUTPUT BIT 18 V SS 1 40 OUTPUT BIT 17 2 39 OUTPUT BIT 19 OUTPUT BIT 17 2 39 OUTPUT BIT 16 3 38 OUTPUT BIT 20 OUTPUT BIT 16 3 38 OUTPUT BIT 15 4 37 OUTPUT BIT 21 OUTPUT BIT 15 4 37 OUTPUT BIT 14 5 36 OUTPUT BIT 22 OUTPUT BIT 14 5 36 OUTPUT BIT 13 6 35 OUTPUT BIT 23 OUTPUT BIT 13 6 35 OUTPUT BIT 12 7 34 OUTPUT BIT 24 OUTPUT BIT 12 7 34 OUTPUT BIT 11 8 33 OUTPUT BIT 25 OUTPUT BIT 11 8 33 OUTPUT BIT 10 9 32 OUTPUT BIT 26 OUTPUT BIT 10 9 32 OUTPUT BIT 9 10 31 OUTPUT BIT 27 OUTPUT BIT 9 10 31 OUTPUT BIT 8 11 30 OUTPUT BIT 28 OUTPUT BIT 8 11 30 OUTPUT BIT 7 12 29 OUTPUT BIT 29 OUTPUT BIT 7 12 29 OUTPUT BIT 6 13 28 OUTPUT BIT 30 OUTPUT BIT 6 13 28 OUTPUT BIT 5 14 27 OUTPUT BIT 31 OUTPUT BIT 5 14 27 OUTPUT BIT 4 15 26 OUTPUT BIT 32 OUTPUT BIT 4 15 26 OUTPUT BIT 3 16 25 OUTPUT BIT 33 OUTPUT BIT 3 16 25 OUTPUT BIT 2 17 24 OUTPUT BIT 34 OUTPUT BIT 2 17 24 OUTPUT BIT 1 18 23 DATA ENABLE OUTPUT BIT 1 18 23 BRIGHTNESS 19 CONTROL V DD 20 22 OUTPUT BIT 18 MM5450BN BRIGHTNESS 19 CONTROL V DD 20 22 DATA IN 21 CLOCK IN 21 Figure 3a, 3b. MM5450/5451 2 May 2000 MM5450/5451 Micrel OUTPUT BIT 20 OUTPUT BIT 21 OUTPUT BIT 22 3 OUTPUT BIT 19 OUTPUT BIT 17 4 OUTPUT BIT 18 OUTPUT BIT 16 5 V SS OUTPUT BIT 15 6 NC OUTPUT BIT 14 Connection Diagram: Plastic Leaded Chip Carrier 2 1 44 43 42 41 40 OUTPUT BIT 13 7 39 OUTPUT BIT 23 OUTPUT BIT 12 8 38 OUTPUT BIT 24 OUTPUT BIT 11 9 37 OUTPUT BIT 25 OUTPUT BIT 10 10 36 OUTPUT BIT 26 OUTPUT BIT 9 11 35 OUTPUT BIT 27 MM5450BV 34 NC OUTPUT BIT 8 13 33 OUTPUT BIT 28 OUTPUT BIT 7 14 32 OUTPUT BIT 29 OUTPUT BIT 6 15 31 OUTPUT BIT 30 OUTPUT BIT 5 16 30 OUTPUT BIT 31 29 OUTPUT BIT 32 7 39 OUTPUT BIT 23 8 38 9 37 10 36 11 35 NC 12 34 13 33 14 32 15 31 16 30 17 29 NC 12 OUTPUT BIT 4 17 OUTPUT BIT 13 18 19 20 21 OUTPUT BIT 33 OUTPUT BIT 22 2 1 44 43 42 41 40 22 CLOCK IN OUTPUT BIT 21 OUTPUT BIT 34 28 OUTPUT BIT 20 DATA ENABLE 27 OUTPUT BIT 19 DATA IN 26 OUTPUT BIT 18 3 25 NC 4 24 V DD BRIGHTNESS CONTROL OUTPUT BIT 17 5 23 V SS OUTPUT BIT 1 6 22 NC OUTPUT BIT 2 OUTPUT BIT 16 21 OUTPUT BIT 15 20 OUTPUT BIT 3 19 OUTPUT BIT 14 18 24 25 26 27 28 Figure 4a, 4b. May 2000 3 MM5450/5451 MM5450/5451 Micrel Absolute Maximum Ratings Operating 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 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 Condition Power Supply Current –25°C to +85°C, excluding output loads –40°C to +85°C, excluding output loads Data Input Voltage VL VH Min logic-0 level, ±10µA input bias logic-1 level, 4.75V ≤ VDD ≤ 5.25V VDD > 5.25V Brightness Control Input Current Note 2 Output Sink Current segment off, VOUT = 3.0V Typ Max Units 8.5 10 mA mA –0.3 2.2 VDD–2 0.8 VDD VDD V V V 0 0.75 mA 10 µA 10 4 25 µA mA mA 4.3 V segment on, VOUT = 1.0V, Note 3 brightness input = 0µA brightness input = 100µA brightness input = 750µA 0 2.0 15 Brightness Control Input Voltage input current = 750µA 3.0 Output Matching Note 1 ±20 % fC Clock Input Frequency Notes 5, 6 500 kHz tH Clock Input High Time Notes 5, 6 950 ns tL Clock Input Low Time Notes 5, 6 950 ns tDS Data Input Setup Time 300 ns tDH Data Input Hold Time 300 ns tDES Data Enable Input Setup Time 100 ns 8 µA Reset Pad Current die 2.7 Note 1: Output matching is calculated as the percent variation (IMAX + IMIN) ÷ 2. Note 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. Note 3: See Figures 7, 8 and 9 for recommended operating conditions and limits. Absolute maximum for each output should be limited to 40mA. Note 4: VOUT should be regulated by the user. See Figures 8 and 9 for allowable VOUT vs. IOUT operation. Note 5: AC input waveform specification for test purpose: tR ≤ 20ns, tF ≤ 20ns, f = 500kHz, 50% ±10% duty cycle. Note 6: Clock input rise and fall times must not exceed 300ns. MM5450/5451 4 May 2000 MM5450/5451 Micrel Functional Description There must be a complete set of 36 clocks or the shift registers will not clear. 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. 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. 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. 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. 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. 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. 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. TJ = (VOUT) (ILED) (No. of segments) (124°C/W) + TA 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. where: 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. ILED = the LED current TJ = junction temperature + 150°C max VOUT = the voltage at the LED driver outputs 124°C/W = thermal resistance of the package TA = ambient temperature The above equation was used to plot Figures 7–9. CLOCK DATA 300 nS MIN DATA ENABLE 100 nS MIN Figure 5. 1 36 37 CLOCK START BIT 1 BIT 35 BIT 36 DATA LOAD (INTERNAL) RESET (INTERNAL) Figure 6. Input Data Format May 2000 5 MM5450/5451 MM5450/5451 Micrel Typical Performance Characteristics 110 2.5 T A = 85°C TA = 85°C TJ = 150°C (MAX) VOUT = 1V 100 2.0 80 20 M M VOUT = 2V 50 G M EG 60 1.5 SE EG VOUT (VO ) 70 S 30 VOUT = 1.5V S 34 OUTPUT CURRENT (mA) 90 1.0 40 30 0.5 20 10 0 0 0 5 10 15 20 25 34 30 0 4 8 NUMBER OF SEGMENTS Figure 7. 12 16 20 24 28 ILED (mA) Figure 8. 1.0 34 SEGMENTS VOUT = 1V 15 mA/SEGMENT POWER DISSIPATION (W) 0.8 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 5V 240 Ω 1k ∆V I 19 – 20 5k LM324 2N2907 CD4046 (VCO) + I 19 = ∆V 1K 5V 20 1 PIN 19 MM74HC123 Q 19 MM5450 10 µS 1 MM5450 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 Typical Applications LED DISPLAY AM FM 34 MM5450 DISPLAY DRIVER ELECTRONIC TUNING CONTROLLER KEYBOARD PLL SYNTHESIZER STATION DETECT, ETC. Figure 12. Basic Electronically Tuned Radio System VLED = 3.0V VLED = 3.0V VLED 9–16 VLED 2–8, 40 32–39 24–31 MM5450 18 21 22 19 20 CLOCK IN DATA IN BRIGHTNESS CONTROL 1 23 17 VDD 100k TYP. Figure 13. Duplexing 8 Digits with One MM5450. May 2000 7 MM5450/5451 MM5450/5451 Micrel Package Information .080 NOM 2.040 20 1 .546 ±.010 .100 .030 NOM 105°/90° 21 .625±.025 40 .010 .075 .020 MIN .150 .060 ± .002 .018 TYP .100 TYP .125 MIN 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 0.062 TYP 0.652 0.030 TYP 0.690 ±0.005 SIDE VIEW BOTTOM VIEW 0.045 0.045 0.137 TYP 0.035 R ±0.010 .610 ±.015 0.062 DIA x 0.020 DEEP DETAIL A 0.125 DIA x 0.005 DEEP 4 PLCS (EJECTOR PIN) 0.020 MIN 0.104 0.172 44-Pin PLCC (V) MICREL INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB USA 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 May 2000