M5480B7

M5480 LED DISPLAY DRIVER FEATURES SUMMARY ■ 3 1/2 DIGIT LED DRIVER (23 segments) ■ CURRENT GENERATOR OUTPUTS (no resistors required) ■ CONTINUOUS BRIGHTNESS CONTROL ■ SERIAL DATA INPUT ■ NO LOAD SIGNAL REQUIRED ■ WIDE SUPPLY VOLTAGE OPERATION ■ TTL COMPATIBILITY Figure 1. Package 28 c u d 1 Application Examples: ■ MICROPROCESSOR DISPLAY ■ INDUSTRIAL CONTROL INDICATION ■ RELAY DRIVER ■ INSTRUMENTATION READOUTS ) s t( o r P PDIP28 (Plastic Package) e t le o s b O - DESCRIPTION The M5480 is a monolithic MOS integrated circuit produced with a N-channel silicon gate technology. It utilizes the M5451 die packaged in a 28-pin plastic package making it ideal for a 3 1/2 digit dispaly. A single pin controls the LED dispaly brightness by setting a reference current through a variable resistor connected either to VDD or to a separate supply of 13.2V maximum. The M5480 is a pin-to-pin replacement of the NS MM 5480. ) s ( ct u d o r P e t e l o s b O REV. 2 April 2004 1/10 M5480 Figure 2. Pin Connections VSS 1 28 OUTPUT BIT 12 OUTPUT BIT 11 2 27 OUTPUT BIT 13 OUTPUT BIT 10 3 26 OUTPUT BIT 14 OUTPUT BIT 9 4 25 OUTPUT BIT 15 OUTPUT BIT 8 5 24 OUTPUT BIT 16 OUTPUT BIT 7 6 23 OUTPUT BIT 17 OUTPUT BIT 6 7 22 OUTPUT BIT 18 OUTPUT BIT 5 8 21 OUTPUT BIT 19 OUTPUT BIT 4 9 20 OUTPUT BIT 20 OUTPUT BIT 3 10 19 OUTPUT BIT 21 OUTPUT BIT 2 11 18 OUTPUT BIT 22 OUTPUT BIT 1 12 17 OUTPUT BIT 23 BRIGHTNESS CONTROL 13 16 DATA IN VDD 14 15 CLOCK IN c u d Figure 3. Block Diagram VDD 14 13 1nF ) s ( ct SERIAL DATA o r P e t e l o s b O 2/10 e t le OUTPUT BIT 23 BRITGHTNESS CONTROL du CLOCK 16 OUTPUT BIT 1 17 o s b O - o r P 12 35 OUTPUT BUFFERS LOAD 35 LATCHES 35 BIT SHIFT REGISTER RESET 15 1 ) s t( M5480 Table 1. Absolute Maximum Ratings Symbol Parameter VDD VI VO(off) IO PTOT Tj 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 940 mW Total Package Power Dissipation at 85°C 490 mW Junction Temperature 150 °C – 25 to 85 °C – 65 to 150 °C TOP Operating Temperature Range TSTG Storage Temperature Range Note: Stresses in excess of those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions in excess of 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. c u d 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.,75 IDD Supply Current VDD = 13.2V VI Input Voltage Logical "0" Level ± 10µA Input Bias 4.75 ≤ VDD ≤ 5.25 Logical "1" Level VDD > 5.25 IB Brightness Input Current (note 2) VB Brightness Input Voltage (pin 13) VO(off) IO Off State Out. Voltage fclock t e l o IO Note: 1. 2. 3. 4. o r P e b O - Typ. du Input Clock Frequency Max. Unit 13.2 V 7 mA - 0.3 0.08 V 2.2 VDD V VDD - 2 VDD V 0 0.75 3 4.3 13.2 VO = 3V Segment OFF Segment ON so Input Current = 750µA, Tamb = 25°C ) s ( ct Out. Sink Current (note 3) e t le o r P Min. ) s t( mA V 18 V 10 µA VO = 1V (note 4) Brightness In. = 0µA 0 Brightness In. = 100µA 2 2,7 Brightness In. = 750µA 12 15 0 Output Matching (note 1) 10 µA 4 mA 25 mA 0.5 MHz ± 20 % 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. s b O 3/10 M5480 FUNCTIONAL DESCRIPTION The M5480 is specifically designed to operate 31/ 2 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 nonmultiplexed, 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 for LED displays. A 1nF capacitor should be connected to brightness control, pin 13, to prevent possible oscillations. A block diagram is shown in Figure 3. The output current is typically 20 times greater than the current into pin 13, which is set by an external variable resistor. There is an internal limiting resistor of 400 Ω 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 register, thus allowing continuous operation. Figure 4. Input Data Format 1 36 CLOCK START BIT 1 BIT 34 e t le DATA LOAD (INTERNAL) ) s ( ct RESET (INTERNAL) du t e l o s b O 4/10 o r P BIT 35 o s b O - 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. Figure 5 shows the timing relationships between Data, and Clock. A maximum clock frequency of 0.5MHz is assumed. Table 3 shows the Output Data Format for the M5480. Because it uses only 23 of the possible 35 outputs, 12 of the bits are "Don’t Care". For applications where a lesser number of outputs are used, it is possible to either increase the cur- o r P e c u d ) s t( rent 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 . 7 mA] (132 °C/W) + Tamb where: Tj = junction temperature (150 °C max) VOUT = the voltage at the LED driver outputs ILED = the LED current 132 °C/W = thermal coefficient of the package Tamb = ambient temperature M5480 Figure 5. CLOCK DATA 300ns (min.) Table 3. Serial Data Bus / Outputs Correspondance 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 5480 X 23 22 21 20 19 X X 18 X 17 16 15 14 5451 18 17 16 15 14 13 12 11 10 9 8 7 6 5 5480 X X X 11 10 9 8 X X X 7 6 5 4 d o r uc 5451 Figure 6. Basic 3 1/2 Digit Interface ) s ( ct r P e s b O t e l o 19 START 13 12 X START 4 3 2 1 START 3 2 1 X START P e let o s b O - TYPICAL APPLICATION u d o 20 ) s t( 23 SEGMENTS M5480 DISPLAY DRIVER CLOCK DATA 5/10 M5480 POWER DISSIPATION OF THE IC The power dissipation of the IC can be limited using different configurations. Figure 8. +VC Figure 7. +VC R ID VD VOUT In this application R must be chosen taking into account the worst operating conditions. R is determined by the maximum number of segments activated. c u d e t le Figure 9. so V –V –V C DMAX OMIN R = ---------------------------------------------------------------N L MAX D b O - 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. o r P e c u d (t s) ) s t( In this configuration the drop on the serial connected diodes is quite stable if the diodes are properly chosen. The total power dissipation of the IC depends, in a first approximation, only on the number of segments activated. o r P +VC VOUT+ VD t e l o s b O 6/10 In this configuration VOUT + VD is constant. The total power dissipation of the IC depends only on the number of segments activated. M5480 PART NUMBERING Table 4. Order Codes Part Number Package Temperature Range M5480 PDIP28 -25 to 85 °C c u d e t le ) s ( ct ) s t( o r P o s b O - u d o r P e t e l o s b O 7/10 M5480 PACKAGE MECHANICAL Table 5. PDIP28 - Mechanical Data millimeters inches Symbol Typ Min Max Typ Max a1 0.63 0.025 b 0.45 0.018 b1 0.23 0.31 b2 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 i 4.445 0.175 L 3.3 0.130 c u d c u d e3 o r P e t e l o e D 28 15 1 14 Note: Drawing is not to scale b1 E F s b O (t s) b2 L a1 o s b O - o r P I e t le b ) s t( 0.555 Figure 10. PDIP28 - Package Dimensions 8/10 Min M5480 REVISION HISTORY Table 6. Revision History Date Revision Description of Changes May-1993 1 First Issue 14-Apr-2004 2 Stylesheet update. No content change. c u d e t le ) s ( ct ) s t( o r P o s b O - u d o r P e t e l o s b O 9/10 M5480 c u d e t le ) s ( ct ) s t( o r P o s b O - u d o r P e t e l o 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. s b O The ST logo is a registered trademark of STMicroelectronics. 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