max7219.docx

1、max7219_General DescriptionThe MAX7219/MAX7221 are compact, serial input/out-put common-cathode display drivers that interfacemicroprocessors (Ps) to 7-segment numeric LED dis-plays of up to 8 digits, bar-graph displays, or 64 indi-vidual LEDs. Included on-chip are a BCD code-Bdecoder, multiplex sca

2、n circuitry, segment and digitdrivers, and an 8x8 static RAM that stores each digit.Only one external resistor is required to set the seg-ment current for all LEDs. The MAX7221 is compatiblewith SPI, QSPI, and Microwire, and has slew-rate-limited segment drivers to reduce EMI.A convenient 3-wire ser

3、ial interface connects to allcommon Ps. Individual digits may be addressed andupdated without rewriting the entire display. TheMAX7219/MAX7221 also allow the user to select code-B decoding or no-decode for each digit.The devices include a 150A low-power shutdownmode, analog and digital brightness co

4、ntrol, a scan-limit register that allows the user to display from 1 to 8digits, and a test mode that forces all LEDs on._ApplicationsBar-Graph Displays7-Segment DisplaysIndustrial ControllersPanel MetersLED Matrix Displays_Featureso10MHz Serial InterfaceoIndividual LED Segment ControloDecode/No-Deco

5、de Digit Selectiono150A Low-Power Shutdown (Data Retained)oDigital and Analog Brightness ControloDisplay Blanked on Power-UpoDrive Common-Cathode LED DisplayoSlew-Rate Limited Segment Driversfor Lower EMI (MAX7221)oSPI, QSPI, Microwire Serial Interface (MAX7221)o24-Pin DIP and SO PackagesSerially In

6、terfaced, 8-Digit LED Display Drivers_Maxim Integrated Products1( ) MAX7221 ONLY8-DIGITP DISPLAYDIG 0DIG 7MOSII/OSCK181121394DINPISET9.53k8 DIGITS8 SEGMENTS+5V19SEG AG,SEG DPCLKLOAD (CS)GNDV+GNDMAX7219MAX7221_Typical Application Circuit_Pin Configuration242322212019181712345678DOUTSEG DSEG DPSEG EGN

7、DDIG 4DIG 0DINTOP VIEWSEG CV+ISETSEG GDIG 7DIG 3DIG 2DIG 6161514139101112SEG BSEG FSEG ACLK( ) MAX7221 ONLY LOAD (CS)DIG 1DIG 5GNDDIP/SOMAX7219MAX722119-4452; Rev 3; 7/97PARTMAX7219CNGMAX7219CWGMAX7219C/D0C to +70C0C to +70C0C to +70CTEMP. RANGEPIN-PACKAGE24 Narrow Plastic DIP24 Wide SODice*_Orderin

8、g InformationOrdering Information continued at end of data sheet.*Dice are specified at TA= +25C.MAX7219ENGMAX7219EWGMAX7219ERG-40C to +85C-40C to +85C-40C to +85C24 Narrow Plastic DIP24 Wide SO24 Narrow CERDIPSPI and QSPI are trademarks of Motorola Inc. Microwire is a trademark of National Semicond

9、uctor Corp.For free samples & the latest literature: http:/www.maxim-, or phone 1-800-998-8800.For small orders, phone 408-737-7600 ext. 3468. MAX7219/MAX7221Serially Interfaced, 8-Digit LED Display Drivers2_ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V+ = 5V 10%, RSET= 9.53k1%, TA= TMINto TM

10、AX, unless otherwise noted.)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functionaloperation of the device at these or any other conditions beyond those indicated in the operational sections of the specific

11、ations is not implied. Exposure toabsolute maximum rating conditions for extended periods may affect device reliability.Voltage (with respect to GND)V+ .-0.3V to 6VDIN, CLK, LOAD,CS.-0.3V to 6VAll Other Pins.-0.3V to (V+ + 0.3V)CurrentDIG0DIG7 Sink Current.500mASEGAG, DP Source Current.100mAContinuo

12、us Power Dissipation (TA= +85C)Narrow Plastic DIP .0.87WWide SO .0.76WNarrow CERDIP.1.1WOperating Temperature RangesMAX7219C_G/MAX7221C_G .0C to +70CMAX7219E_G/MAX7221E_G .-40C to +85CStorage Temperature Range .-65C to +160CLead Temperature (soldering, 10sec) .+300CRSET= open circuitAll digital inpu

13、ts at V+ or GND, TA= +25CDigit off, VDIGIT= V+TA= +25C, V+ = 5V, VOUT= (V+ - 1V)All segments and decimal point on,ISEG_= -40mA8 digits scannedV+ = 5V, VOUT= 0.65VTA= +25C, V+ = 5V, VOUT= (V+ - 1V)CONDITIONS8Operating Supply CurrentA150I+V4.05.5V+Operating Supply VoltageShutdown Supply CurrentA-10IDI

14、GITDigit Drive Leakage(MAX7221 only)%3.0ISEGSegment Drive Current MatchingmA/s102050ISEG/tSegment Current Slew Rate(MAX7221 only)mA330I+Hz5008001300fOSCDisplay Scan RatemA320IDIGITDigit Drive Sink CurrentmA-30-40-45ISEGSegment Drive Source CurrentUNITSMINTYPMAXSYMBOLPARAMETERSegment off, VSEG= 0VA1I

15、SEGSegment Drive Leakage(MAX7221 only)Digit off, VDIGIT= (V+ - 0.3V)mA-2IDIGITDigit Drive Source Current(MAX7219 only)Segment off, VSEG= 0.3VmA5ISEGSegment Drive Sink Current(MAX7219 only) MAX7219/MAX7221Serially Interfaced, 8-Digit LED Display Drivers_3ELECTRICAL CHARACTERISTICS (continued)(V+ = 5V

16、 10%, RSET=9.53k1%, TA= TMINto TMAX, unless otherwise noted.)VIN= 0V or V+DOUT, ISINK= 1.6mADOUT, ISOURCE= -1mACONDITIONSA-11IIH, IILInput Current DIN, CLK,LOAD,CSV0.4VOLOutput Low VoltageV3.5VIHLogic High Input VoltageV0.8VILLogic Low Input VoltageVV+ - 1VOHOutput High VoltageUNITSMINTYPMAXSYMBOLPA

17、RAMETERDIN, CLK, LOAD,CSV1VIHysteresis Voltagens25tCSSCSFall to SCLK Rise Setup Time(MAX7221 only)ns100tCPCLK Clock Periodns50tCHCLK Pulse Width Highns50tCLCLK Pulse Width LowCLOAD= 50pFns25tDSDIN Setup Timens50tCSWMinimumCSor LOAD PulseHighns0tDHDIN Hold Timens25tDOOutput Data Propagation Delayns50

18、tLDCKLoad-Rising Edge to Next ClockRising Edge (MAX7219 only)ns0tCSHCLK Rise toCSor LOAD RiseHold Timems2.25tDSPDData-to-Segment DelayLOGIC INPUTSTIMING CHARACTERISTICS MAX7219/MAX7221Serially Interfaced, 8-Digit LED Display Drivers4_Typical Operating Characteristics(V+ = +5V, TA= +25C, unless other

19、wise noted.)7307507407707607907808008208108304.04.44.85.25.66.0SCAN FREQUENCY vs.POSITIVE SUPPLY VOLTAGEPOSITIVE SUPPLY VOLTAGE (V)020104030605070012345SEGMENT DRIVER OUTPUT CURRENTvs. OUTPUT VOLTAGEOUTPUT VOLTAGE (V)RSET = 10kRSET = 20kRSET = 40kMAX7219SEGMENT OUTPUT CURRENT5s/div10mA/div0MAXIMUM I

20、NTENSITY = 31/32MAX7221SEGMENT OUTPUT CURRENT5s/div10mA/div0MAXIMUM INTENSITY = 15/16 MAX7219/MAX7221 MAX7219/21 01 SCAN FREQUENCY (Hz) MAX7219/21 02 OUTPUT CURRENT (mA) MAX7219/21 03 MAX7219/21 04Serially Interfaced, 8-Digit LED Display Drivers_5_Pin Description_Functional DiagramNAMEFUNCTION1DINSe

21、rial-Data Input. Data is loaded into the internal 16-bit shift register on CLKs rising edge.2, 3, 58,10, 11DIG 0DIG 7Eight-Digit Drive Lines that sink current from the display common cathode. The MAX7219 pullsthe digit outputs to V+ when turned off. The MAX7221s digit drivers are high-impedance when

22、turned off.PIN4, 9GNDGround (both GND pins must be connected)12LOAD(MAX7219)18ISETConnect to VDDthrough a resistor (RSET) to set the peak segment current (Refer toSelectingRSETResistor section).1417,2023SEG ASEG G,DP13CLKCS(MAX7221)24DOUTSerial-Data Output. The data into DIN is valid at DOUT 16.5 cl

23、ock cycles later. This pin is usedto daisy-chain several MAX7219/MAX7221s and is never high-impedance.19V+Positive Supply Voltage. Connect to +5V.( ) MAX7221 ONLYV+88884RSETLOAD (CS)DINDOUTCLK(MSB)(LSB)D0SEG ASEG G, DPDIG 0DIG 7SHUTDOWN REGISTERMODE REGISTERINTENSITY REGISTERSCAN-LIMIT REGISTERDISPL

24、AY-TEST REGISTERINTENSITYPULSE-WIDTHMODULATORMULTIPLEXSCANCIRCUITRYADDRESSREGISTERDECODER8x8DUAL-PORTSRAM8D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12DIGIT DRIVERSD13 D14 D15CODE BROM WITHBYPASSSEGMENTCURRENTREFERENCESEGMENT DRIVERSLoad-Data Input. The last 16 bits of serial data are latched on LOADs risi

25、ng edge.Chip-Select Input. Serial data is loaded into the shift register whileCSis low. The last 16 bits ofserial data are latched onCSs rising edge.Serial-Clock Input. 10MHz maximum rate. On CLKs rising edge, data is shifted into the inter-nal shift register. On CLKs falling edge, data is clocked out of DOUT. On the MAX7221, theCLK input is active only whileCSis low.Seven Segment Drives and Decimal Point Drive that source current to the display. On theMAX7219, when a segment driver is turned off it is