M5480 LED DISPLAY DRIVER .. .. .. . .. .. 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 Applications examples MICROPROCESSOR DISPLAYS INDUSTRIAL CONTROL INDICATION RELAY DRIVER INSTRUMENTATION READOUTS DIP-28 (Plastic Package) 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 plas-tic 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. ORDER CODE : M5480B7 May 1993 V SS 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 V DD 14 15 CLOCK IN 5480-01.EPS PIN CONNECTIONS 1/6 M5480 BLOCK DIAGRAM (Figure 1) V DD BRITGHTNESS CONTROL 14 13 OUTPUT BIT 23 OUTPUT BIT 1 17 12 35 OUTPUT BUFERS 1nF LOAD 35 LATCHES SERIAL DATA 16 CLOCK 15 35 BIT SHIFT REGISTER 5480-02.EPS RESET 1 Symbol VDD VI VO (off) IO Ptot Tj Toper Tstg Parameter Supply Voltage Input Voltage Off State Output Voltage Output Sink Current Total Package Power Dissipation at 25 °C at 85 °C Junction Temperature Operating Temperature Range Storage Temperature Range Value – 0.3 to 15 – 0.3 to 15 15 40 940 490 150 – 25, + 85 – 65, + 150 Unit V V V mA mW mW °C °C °C 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. 2/6 5480-01.TBL ABSOLUTE MAXIMUM RATINGS M5480 Symbol Parameter Supply Voltage VDD IDD Supply Current Input Voltages Logical "0" Level VI Logical "1" Level IB VB VO(off) IO Brightness Input Current (note 2) Brightness Input Voltage (pin 13) Off State Output Voltage Output Sink Current (note 3) Segment OFF Segment ON fclock IO Test Conditions Min. 4.75 VDD = 13.2 V ± 10 µA Input Bias 4.75 ≤ VDD ≤ 5.25 VDD > 5.25 Input Current = 750µA, Tamb = 25oC – 0.3 2.2 VDD – 2 0 3 13.2 VO = 3 V VO = 1 V (note 4) Brightness In. = 0 µA Brightness In. = 100 µA Brightness In. = 750 µA 0 2 12 0 Input Clock Frequency Output Matching (note 1) Notes : 1. 2. 3. 4. Typ. 2.7 15 Max. 13.2 7 0.8 VDD VDD 0.75 4.3 18 Unit V mA V V V mA V V 10 µA 10 4 25 0.5 ± 20 µA mA mA MHz % 5480-02.TBL STATIC ELECTRICAL CHARACTERISTICS (Tamb within operating range, VDD = 4.75V to 13.2V, VSS = 0V,unless otherwise specified) Output matching is calculated as the percent variation from IMAX + 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 40 mA. The VO voltage should be regulated by the user FUNCTIONAL DESCRIPTION The M5480 is specifically designed to operate 3 1/2 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 1. 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 2 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 2 : Input Data Format 1 36 CLOCK START BIT 1 BIT 34 BIT 35 DATA 5480-03.EPS LOAD (INTERNAL) RESET (INTERNAL) 3/6 M5480 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 3 shows the timing relationships between Data, and Clock. A maximum clock frequency of 0.5MHz is assumed. Figure 4 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 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 . 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 Figure 3 DATA 300ns (min.) 5480-04.EPS CLOCK 5451 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 START 5480 X 23 22 21 20 19 X X 18 X 17 16 15 14 13 12 X START 5451 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 START 5480 X X X 11 10 9 8 X X X 7 6 5 4 3 2 1 X START TYPICAL APPLICATION 5480-03.TBL Figure 4 : Serial Data Bus / Outputs Correspondance +V C a) BASIC 3 1/2 Digit Interface. R ID VD 23 SEGMENTS 5480-06.EPS V OUT M5480 CLOCK DATA POWER DISSIPATION OF THE IC The power dissipation of the IC can be limited using different configurations. 4/6 5480-05.EPS DISPLAY DRIVER In this application R must be chosen taking into account the worst operating conditions. R is determined by the maximum number of segments activated. VC − VD MAX − VOUT MIN R= NMAX ⋅ ID M5480 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. c) +V C +VC 5480-08.EPS V OUT +V D 5480-07.EPS b) 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. In this configuration VOUT + VD is constant. The total power dissipation of the IC depends only on the number of segments activated. 5/6 M5480 I L a1 PACKAGE MECHANICAL DATA 28 PINS - PLASTIC DIP b1 b b2 e E e3 D 15 1 14 a1 b b1 b2 D E e e3 F i L Min. Millimeters Typ. 0.63 0.45 0.23 Max. Min. 0.31 0.009 1.27 Max. 0.012 0.050 37.4 16.68 15.2 Inches Typ. 0.025 0.018 1.470 0.657 0.598 2.54 33.02 0.100 1.300 14.1 4.445 3.3 0.555 0.175 0.130 Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics 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 licence is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics. © 1994 SGS-THOMSON Microelectronics - All Rights Reserved Purchase of I2C Components of SGS-THOMSON Microelectronics, conveys a license under the Philips I2C Patent. Rights to use these components in a I2C system, is granted provided that the system conforms to the I2C Standard Specifications as defined by Philips. SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - China - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco The Netherlands - Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A. 6/6 DIP28.TBL Dimensions PM-DIP28.EPS F 28