Serially Interfaced, 8-Digit LED Display Drivers

1 AVAILABLEF unctional DiagramsPin Configurations appear at end of data Diagrams continued at end of data is a trademark of Maxim Integrated Products, pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim s website at 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 scan circuitry, segment and digitdrivers, and an 8x8 static RAM that stores each one external resistor is required to set the seg-ment current for all LEDs.

2 The MAX7221 is compatiblewith SPI , QSPI , and MICROWIRE , and has slew-rate-limited segment Drivers to reduce convenient 4-wire serial 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 devices include a 150 A low-power shutdownmode, analog and digital brightness control, a scan-limit register that allows the user to Display from 1 to 8digits, and a test mode that forces all LEDs applications requiring 3V operation or segmentblinking, refer to the MAX6951 data 10 MHz Serial Interface Individual LED Segment Control Decode/No-Decode Digit Selection 150 A Low-Power Shutdown (Data Retained) Digital and Analog Brightness Control Display Blanked on Power-Up Drive Common-Cathode LED Display Slew-Rate Limited Segment Driversfor Lower EMI (MAX7221)

3 SPI, QSPI, MICROWIRE Serial Interface (MAX7221) 24-Pin DIP and SO PackagesSerially Interfaced, 8-Digit LED Display Drivers ( ) MAX7221 ONLY8-DIGIT P DISPLAYDIG 0 DIG 7 MOSII/OSCK181121394 DIN 8 DIGITS8 SEGMENTS+5V19 SEG A G,SEG DPCLKLOAD (CS)GNDV+GNDMAX7219 MAX7221 Typical Application CircuitPin Configuration242322212019181712345678 DOUTSEG DSEG DPSEG EGNDDIG 4 DIG 0 DINTOP VIEWSEG CV+ISETSEG GDIG 7 DIG 3 DIG 2 DIG 6161514139101112 SEG BSEG FSEG ACLK( ) MAX7221 ONLY LOAD (CS)DIG 1 DIG 5 GNDDIP/SOMAX7219 MAX722119-4452; Rev 4; 7/03 PARTMAX7219 CNGMAX7219 CWGMAX7219C/D0 C to +70 C0 C to +70 C0 C to +70 CTEMP RANGEPIN-PACKAGE24 Narrow Plastic DIP24 Wide SODice*Ordering InformationOrdering Information continued at end of data sheet.

4 *Dice are specified at TA = +25 C to +85 C-40 C to +85 C-40 C to +85 C24 Narrow Plastic DIP24 Wide SO24 Narrow CERDIPSPI and QSPI are trademarks of Motorola Inc. MICROWIRE is a trademark of National Semiconductor DisplaysIndustrial ControllersPanel MetersLED Matrix DisplaysMAX7219/MAX7221 Serially Interfaced, 8-Digit LED Display DriversABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V+ = 5V 10%, RSET = 1%, TA= TMINto TMAX, 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 specifications is not implied.

5 Exposure toabsolute maximum rating conditions for extended periods may affect device (with respect to GND)V+ .. to 6 VDIN, CLK, LOAD, to 6 VAll Other to (V+ + )CurrentDIG 0 DIG 7 Sink A G, DP Source Power Dissipation (TA= +85 C)Narrow Plastic DIP (derate C above +70 C)..1066mWWide SO (derate C above +70 C)..941mWNarrow CERDIP (derate C above +70 C) ..1000mWOperating Temperature Ranges (TMINto TMAX)MAX7219C_G/MAX7221C_G ..0 C to +70 CMAX7219E_G/MAX7221E_G ..-40 C to +85 CStorage Temperature Range ..-65 C to +160 CLead Temperature (soldering, 10s) ..+300 CRSET= open circuitAll digital inputs at V+ or GND, TA= +25 CDigit off, VDIGIT= V+TA= +25 C, V+ = 5V, VOUT= (V+ - 1V)All segments and decimal point on,ISEG_= -40mA8 digits scannedV+ = 5V, VOUT= +25 C, V+ = 5V, VOUT= (V+ - 1V)CONDITIONS8 Operating Supply Current A150I+ +Operating Supply VoltageShutdown Supply Current A-10 IDIGITD igit Drive Leakage (MAX7221 only)% ISEGS egment Drive Current MatchingmA/ s102050 ISEG/ tSegment Current Slew Rate(MAX7221 only)mA330I+Hz5008001300fOSCD isplay Scan RatemA320 IDIGITD igit Drive Sink CurrentmA-30-40-45 ISEGS egment Drive Source CurrentUNITSMINTYPMAXSYMBOLPARAMETERS egment off, VSEG= 0V A1 ISEGS egment Drive Leakage (MAX7221 only)Digit off, VDIGIT= (V+ - )

6 MA-2 IDIGITD igit Drive Source Current (MAX7219 only)Segment off, VSEG= Drive Sink Current (MAX7219 only)MAX7219/MAX72212 Maxim IntegratedSerially Interfaced, 8-Digit LED Display DriversELECTRICAL CHARACTERISTICS (continued)(V+ = 5V 10%, RSET = 1%, TA= TMINto TMAX, unless otherwise noted.)VIN= 0V or V+DOUT, ISINK= , ISOURCE= -1mACONDITIONS A-11 IIH, IILI nput Current DIN, CLK, LOAD, Low High Input Low Input VoltageVV+ - 1 VOHO utput High VoltageUNITSMINTYPMAXSYMBOLPARAMETERDIN, CLK, LOAD, CSV1 VIHysteresis Voltagens25tCSSCSFall to SCLK Rise Setup Time(MAX7221 only)ns100tCPCLK Clock Periodns50tCHCLK Pulse Width Highns50tCLCLK Pulse Width LowCLOAD= 50pFns25tDSDIN Setup Timens50tCSWM inimum CSor LOAD PulseHighns0tDHDIN Hold Timens25tDOOutput Data Propagation Delayns50tLDCKLoad-Rising Edge to Next ClockRising Edge (MAX7219 only)

7 Ns0tCSHCLK Rise to CSor LOAD RiseHold DelayLOGIC INPUTSTIMING CHARACTERISTICSMAX7219/MAX7221 Maxim Integrated3 Serially Interfaced, 8-Digit LED Display Drivers_____Typical Operating Characteristics(V+ = +5V, TA = +25 C, unless otherwise noted.) FREQUENCY vs. POSITIVE SUPPLY VOLTAGEMAX7219/21 01 POSITIVE SUPPLY VOLTAGE (V)SCAN FREQUENCY (Hz)020104030605070012345 SEGMENT DRIVER OUTPUT CURRENTvs. OUTPUT VOLTAGEMAX7219/21 02 OUTPUT VOLTAGE (V)OUTPUT CURRENT (mA)RSET = 10k RSET = 20k RSET = 40k MAX7219 SEGMENT OUTPUT CURRENTMAX7219/21 035 s/div10mA/div0 MAXIMUM INTENSITY = 31/32 MAX7221 SEGMENT OUTPUT CURRENTMAX7219/21 045 s/div10mA/div0 MAXIMUM INTENSITY = 15/16 MAX7219/MAX72214 Maxim IntegratedSerially Interfaced, 8-Digit LED Display DriversPin DescriptionFunctional DiagramNAMEFUNCTION1 DINS erial-Data Input.

8 Data is loaded into the internal 16-bit shift register on CLK s rising , 3, 5 8,10, 11 DIG 0 DIG 7 Eight-Digit Drive Lines that sink current from the Display common cathode. The MAX7219 pullsthe digit outputs to V+ when turned off. The MAX7221 s digit Drivers are high-impedance whenturned , 9 GNDG round (both GND pins must be connected)12 LOAD(MAX7219)18 ISETC onnect to VDDthrough a resistor (RSET) to set the peak segment current (Refer to SelectingRSETR esistor and Using External Drivers section).14 17,20 23 SEG A SEG G,DP13 CLKCS(MAX7221)24 DOUTS erial-Data Output. The data into DIN is valid at DOUT clock cycles later. This pin is usedto daisy-chain several MAX7219/MAX7221 s and is never +Positive Supply Voltage.

9 Connect to +5V.( ) MAX7221 ONLYV+88884 RSETLOAD (CS)DINDOUTCLK(MSB)(LSB)D0 SEG A SEG G, DPDIG 0 DIG 7 SHUTDOWN REGISTERMODE REGISTERINTENSITY REGISTERSCAN-LIMIT REGISTERDISPLAY-TEST REGISTERINTENSITYPULSE-WIDTHMODULATORMUL TIPLEXSCANCIRCUITRYADDRESSREGISTERDECODE R8x8 DUAL-PORTSRAM8D1D2D3D4D5D6D7D8D9D10D11D1 2 DIGIT DRIVERSD13D14D15 CODE BROM WITHBYPASSSEGMENTCURRENTREFERENCESEGMENT DRIVERSLoad-Data Input. The last 16 bits of serial data are latched on LOAD s rising Input. Serial data is loaded into the shift register while CSis low. The last 16 bits ofserial data are latched on CS s rising Input. 10 MHz maximum rate. On CLK s rising edge, data is shifted into the inter-nal shift register. On CLK s falling edge, data is clocked out of DOUT.

10 On the MAX7221, theCLK input is active only while CSis Segment Drives and Decimal Point Drive that source current to the Display . On theMAX7219, when a segment driver is turned off it is pulled to GND. The MAX7221 segment dri-vers are high-impedance when turned Integrated5 MSBS erially Interfaced, 8-Digit LED Display DriversDetailed Description MAX7219/MAX7221 DifferencesThe MAX7219 and MAX7221 are identical except fortwo parameters: the MAX7221 segment Drivers areslew-rate limited to reduce electromagnetic interfer-ence (EMI), and its serial interface is fully SPI ModesFor the MAX7219, serial data at DIN, sent in 16-bitpackets, is shifted into the internal 16-bit shift registerwith each rising edge of CLK regardless of the state ofLOAD.