M5450 M5451 LED DISPLAY DRIVERS FEATURES SUMMARY ■ M5450 34 OUTPUTS/15mA SINK ■ M5451 35 OUTPUTS/15mA SINK ■ CURRENT GENERATOR OUTPUTS (NO EXTERNAL RESISTORS REQUIRED) ■ CONTINUOUS BRIGHTNESS CONTROL ■ SERIAL DATA INPUT ■ ENABLE (ON M5450) ■ WIDE SUPPLY VOLTAGE OPERATION ■ TTL COMPATIBILITY Figure 1. Packages 40 1 PDIP40 (Plastic Package) Application Examples: ■ MICROPROCESSOR DISPLAYS ■ INDUSTRIAL CONTROL INDICATOR ■ RELAY DRIVER ■ INSTRUMENTATION READOUTS PLCC44 (Plastic Chip Carrier) DESCRIPTION The M5450 and M5451 are monolithic MOS integrated circuits produced with an N-channel silicon gate technology. They are available in 40-pin dual in-line plastic packages. A single pin controls the LED display brightness by setting a reference current through a variable resistor connected to VDD or to a separate supply of 13.2V maximum. REV. 2 April 2004 1/12 M5450, M5451 OUTPUT BIT 20 OUTPUT BIT 21 OUTPUT BIT 22 41 40 1 OUTPUT BIT 19 VSS N.C 2 42 OUTPUT BIT 17 3 OUTPUT BIT 18 OUTPUT BIT 16 4 43 OUTPUT BIT 15 5 44 OUTPUT BIT 14 6 Figure 2. Pin Connection 7 34 OUTPUT BIT 24 OUTPUT BIT 11 9 37 OUTPUT BIT 25 OUTPUT BIT 11 8 33 OUTPUT BIT 25 OUTPUT BIT 10 10 36 OUTPUT BIT 26 OUTPUT BIT 9 11 35 OUTPUT BIT 27 OUTPUT BIT 10 9 32 OUTPUT BIT 26 N.C. 12 34 N.C. OUTPUT BIT 9 10 31 OUTPUT BIT 27 OUTPUT BIT 8 13 33 OUTPUT BIT 28 OUTPUT BIT 8 11 30 OUTPUT BIT 28 OUTPUT BIT 7 14 32 OUTPUT BIT 29 OUTPUT BIT 6 15 31 OUTPUT BIT 30 OUTPUT BIT 7 12 29 OUTPUT BIT 29 OUTPUT BIT 5 16 30 OUTPUT BIT 31 OUTPUT BIT 6 13 28 OUTPUT BIT 30 OUTPUT BIT 4 17 29 OUTPUT BIT 32 OUTPUT BIT 5 14 27 OUTPUT BIT 31 OUTPUT BIT 4 15 26 OUTPUT BIT 32 OUTPUT BIT 3 16 25 OUTPUT BIT 33 OUTPUT BIT 2 17 24 OUTPUT BIT 1 18 23 OUTPUT BIT 34 DATA ENABLE FOR M5450 OUTPUT BIT 35 FOR M5451 BRIGHTNESS CONTROL 19 22 DATA IN V DD 20 21 CLOCK IN 28 OUTPUT BIT 24 OUTPUT BIT 12 OUTPUT BIT 33 38 27 8 OUTPUT BIT 34 OUTPUT BIT 23 OUTPUT BIT 12 26 39 OUTPUT BIT 23 25 7 35 24 OUTPUT BIT 13 6 DATA IN OUTPUT BIT 35 OUTPUT BIT 22 OUTPUT BIT 13 CLOCK IN 36 23 5 N.C OUTPUT BIT 21 OUTPUT BIT 14 22 37 VDD 4 21 OUTPUT BIT 20 OUTPUT BIT 15 BRIGHTNESS CONTROL 38 20 3 OUTPUT BIT 1 OUTPUT BIT 19 OUTPUT BIT 16 19 OUTPUT BIT 18 39 18 40 2 OUTPUT BIT 3 1 OUTPUT BIT 2 V SS OUTPUT BIT 17 Figure 3. Block Diagram VDD BRIGTHNESS CONTROL 20 OUTPUT BIT 34 OUTPUT BIT 1 24 18 100kΩ 19 35 OUTPUT BUFFERS LOAD 35 LATCHES DATA ENABLE (M5450) OUTPUT35 (5451) 23 SERIAL DATA 22 CLOCK 21 35-BIT SHIFT REGISTER RESET 1 2/12 M5450, M5451 Table 1. Absolute Maximum Ratings Symbol VDD VI VO(off) IO PTOT Tj Parameter Value Unit Supply Voltage – 0.3 to 15 V Input Voltage – 0.3 to 15 V Off State Output Voltage 15 V Output Sink Current 40 mA Total Package Power Dissipation at 25°C 1 W Total Package Power Dissipation at 85°C 560 mW Junction Temperature 150 °C – 25 to 85 °C – 65 to 150 °C TOP Operating Temperature Range TSTG Storage Temperature Range Note: Stresses above those listed under "Absolute Maximum Ratings" may causes permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. FUNCTIONAL DESCRIPTION Both the M5450 and the M5451 are specially designed to operate 4 or 5-digit alphanumeric displays with minimal interface with the display and the data source. Serial data transfer from the data source to the display driver is accomplished with 2 signals, serial data and clock. Using a format of a leading "1" followed by the 35 data bits allows data transfer without an additional load signal. The 35 data bits are latched after the 36th bit is complete, thus providing non-multiplexed, direct drive to the display. Outputs change only if the serial data bits differ from the previous time. Display brightness is determined by control of the output current LED displays. A 1nF capacitor should be connected to brightness control, pin 19, to prevent possible oscillations. A block diagram is shown in Figure 3. For the M5450 a DATA ENABLE is used instead of the 35th output. The DATA ENABLE input is a metal option for the M5450. The output current is typically 20 times greater than the current into pin 19, which is set by an external variable resistor. There is an internal limiting resistor of 400W nominal value. Figure 4 shows the input data format. A start bit of logical "1" precedes the 35 bits of data. At the 36th clock a LOAD signal is generated synchronously with the high state of the clock, which loads the 35 bits of the shift registers into the latches. At the low state of the clock a RESET signal is generated which clears all the shift registers for the next set of data. The shift registers are static master-slave configurations. There is no clear for the master portion of the first shift register, thus allowing continuous operation. There must be a complete set of 36 clocks or the shift registers will not clear. When power is first applied to the chip 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. 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 relationship between Data, Clock and DATA ENABLE. A max 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) + (VDD × 7mA)] (124°C/W) + Tamb where : Tj = junction temperature (150°C max) VOUT = the voltage at the LED driver outputs ILED = the LED current 124°C/W = thermal coefficient of the package Tamb = ambient temperature The above equation was used to plot Figure 6, Figure 7 and Figure 8. 3/12 M5450, M5451 Table 2. Static Electrical Characteristics (Tamb within operating range, VDD = 4.75V to 13.2V, VSS = 0V, unless otherwise specified) Symbol Parameter Test Conditions VDD Supply Voltage IDD Supply Current VDD = 13.2V VI Input Voltage Logical "0" Level ± 10µA Input Bias Min. 4.75 ≤ VDD ≤ 5.25 Logical "1" Level VDD > 5.25 Max. Unit 4.75 13.2 V 7 mA - 0.3 0.8 V 2.2 VDD V VDD - 2 VDD V IB Brightness Input Current (note 2) 0 0.75 VB Brightness Input Voltage (pin 19) Input Current = 750µA, Tamb = 25°C 3 4.3 VO(off) IO Off State Out. Voltage 13.2 V 10 µA 10 µA VO = 3V VO = 1V (note 4) Segment ON Brightness In. = 0µA fclock IO Note: 1. 2. 3. 4. mA V Out. Sink Current (note 3) Segment OFF 0 Brightness In. = 100µ 2 27 4 mA Brightness In. = 750µA 12 15 25 mA 0.5 MHz ± 20 % Input Clock Frequency 0 Output Matching (note 1) Output matching is calculated as the percent variation from I MAX + IMIN/2. With a fixed resistor on the brightness input some variation in brightness will occur from one device to another. Absolute maximum for each output should be limited to 40mA. The VO voltage should be regulated by the user. See Figure 7 and Figure 8 for allowable VO versus IO operation. Figure 4. Input Data Format 1 36 CLOCK START DATA LOAD (INTERNAL) RESET (INTERNAL) 4/12 Typ. BIT 1 BIT 34 BIT 35 M5450, M5451 Figure 5. Figure 6. 1.0 Ptot (W) 15mA/segment 34 segments VO = 1V CLOCK 0.8 0.6 DATA 0.4 300ns (min.) SAFE OPERATING AREA 0.2 DATA ENABLE T amb (˚C) 100ns (min.) 20 0 Figure 7. 3.2 40 60 80 100 Figure 8. I0 (mA) VO (V) 105 20 segments 30 segments 34 segments 2.8 2.4 Tamb = 85˚C IO (max.) = 40mA 85 2.0 65 VO = 1V VO = 1.5V VO = 2V 1.6 45 1.2 0.8 Tamb = 85˚C 0.4 Tj = 150˚C ˚ (max.) 25 N˚ Segm. ILED (mA) 5 0 4 8 12 16 20 24 28 32 0 4 8 12 16 20 24 28 32 36 40 5/12 M5450, M5451 TYPICAL APPLICATIONS Figure 9. Basic Electronically Tuned Radio Or Tv System AM FM 34 SEGMENTS M5450 DISPLAY DRIVER ELECTRONIC TUNING CONTROLLER KEYBOARD PLL SYNTHESIZER STATION DETEC. ETC. Figure 10. Duplexing 8 Digits With One M5450 VDD VLED . 9 16 . 28 40 . 32 39 . . 24 31 M5450 18 21 22 19 20 1 CLOCK IN DATA IN VDD BRIGHTNESS CONTROL 6/12 VDD VLED 23 17 . . . M5450, M5451 POWER DISSIPATION OF THE IC The power dissipation of the IC can be limited using different configurations. Figure 11- In the application R must be chosen taking into account the worst operating conditions. The total power dissipation of the IC depends, in a first approximation, only on the number of segments activated. Figure 12. Figure 11. +VC +VC R ID VD VOUT R is determined by the maximum number of segments activated V –V –V C DMAX OMIN R = ---------------------------------------------------------------N L MAX D The worst case condition for the device is when roughly half of the maximum number of segments are activated. It must be checked that the total power dissipation does not exceed the absolute maximum ratings of the device. In critical cases more resistors can be used in conjunction with groups of segments. In this case the current variation in the single resistor is reduced and Ptot limited. Figure 12 - In this configuration the drop on the serial connected diodes is quite stable if the diodes are properly chosen. Figure 13 - In this configuration VOUT + VD is constant. The total power dissipation of the IC depends only on the number of segments activated. Figure 13. +VC VOUT +VD 7/12 M5450, M5451 PART NUMBERING Table 3. Order Codes Part Number 8/12 Package Temperature Range M5450B7/M5451B7 PDIP40 -25 to 85 °C M5451Q PLCC44 -25 to 85 °C M5450, M5451 PACKAGE MECHANICAL Table 4. PDIP40 - Mechanical Data millimeters inches Symbol Typ Min Max Typ Min a1 0.63 0.025 b 0.45 0.018 b1 0.23 b2 0.31 Max 0.009 1.27 0.012 0.050 D 52.58 E 15.2 2.070 16.68 0.598 0.657 e 2.54 0.100 e3 48.26 1.900 F 14.1 0.555 i 4.445 0.175 L 3.3 0.130 I L a1 Figure 14. PDIP40 - Package Dimensions b1 b b2 e E e3 D 21 1 20 F 40 Note: Drawing is not to scale 9/12 M5450, M5451 Table 5. PLCC44 - Mechanical Data millimeters inches Symbol Typ Min Max Typ Min Max A 17.4 17.65 0.685 0.695 B 16.51 16.65 0.650 0.656 C 3.65 3.7 0.144 0.146 D 4.2 4.57 0.165 0.180 d1 2.59 2.74 0.102 0.108 d2 0.68 E 14.99 0.027 16 0.590 0.630 e 1.27 0.050 e3 12.7 0.500 F 0.46 0.018 F1 0.71 0.028 G 0.101 0.004 M 1.16 0.046 M1 1.14 0.045 Figure 15. PLCC44 - Package Dimensions C B M M1 2 1 44 39 F M 38 e3 F1 E e M1 6 7 17 29 18 28 d2 A d1 G (Seating Plane Coplanarity) Note: Drawing is not to scale. 10/12 D M5450, M5451 REVISION HISTORY Table 6. Revision History Date Revision Description of Changes September-1993 1 First Issue 14-Mar-2004 2 Stylesheet update. No content change. 11/12 M5450, M5451 Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics. 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