Datasheet Maxim MAX7219C/D — Datenblatt

AVAILAB LE MAX7219/MAX7221 Serially Interfaced, 8-Digit LED Display Drivers
General Description
The MAX7219/MAX7221 are compact, serial input/output common-cathode display drivers that interface microprocessors (µPs) to 7-segment numeric LED displays of up to 8 digits, bar-graph displays, or 64 individual LEDs. Included on-chip are a BCD code-B decoder, multiplex scan circuitry, segment and digit drivers, and an 8x8 static RAM that stores each digit. Only one external resistor is required to set the segment current for all LEDs. The MAX7221 is compatible with SPITM, QSPITM, and MICROWIRETM, and has slewrate-limited segment drivers to reduce EMI. A convenient 4-wire serial interface connects to all common µPs. Individual digits may be addressed and updated without rewriting the entire display. The MAX7219/MAX7221 also allow the user to select codeB decoding or no-decode for each digit. The devices include a 150µA low-power shutdown mode, analog and digital brightness control, a scanlimit register that allows the user to display from 1 to 8 digits, and a test mode that forces all LEDs on. For applications requiring 3V operation or segment blinking, refer to the MAX6951 data sheet. 10MHz Serial Interface Individual LED Segment Control Decode/No-Decode Digit Selection 150µA Low-Power Shutdown (Data Retained) Digital and Analog Brightness Control Display Blanked on Power-Up Drive Common-Cathode LED Display Slew-Rate Limited Segment Drivers for Lower EMI (MAX7221) SPI, QSPI, MICROWIRE Serial Interface (MAX7221) 24-Pin DIP and SO Packages Features Ordering Information
PART MAX7219CNG MAX7219CWG MAX7219C/D MAX7219ENG TEMP RANGE 0°C to +70°C 0°C to +70°C 0°C to +70°C -40°C to +85°C PIN-PACKAGE 24 Narrow Plastic DIP 24 Wide SO Dice* 24 Narrow Plastic DIP Applications
Bar-Graph Displays Industrial Controllers Panel Meters LED Matrix Displays MAX7219EWG -40°C to +85°C 24 Wide SO MAX7219ERG -40°C to +85°C 24 Narrow CERDIP Ordering Information continued at end of data sheet. *Dice are specified at TA = +25°C. Pin Configuration Functional Diagrams
TOP VIEW
DIN 1 DIG 0 2 DIG 4 3 GND 4 DIG 6 5 DIG 2 6 DIG 3 7 DIG 7 8 GND 9 DIG 5 10 DIG 1 11 LOAD (CS) 12 24 DOUT 23 SEG D 22 SEG DP 21 SEG E Typical Application Circuit +5V 19 9.53k 18 ISET V+ DIG 0­DIG 7 8 DIGITS MOSI P I/O SCK 1 12 13 9 MAX7219 MAX7221 20 SEG C 19 V+ 18 ISET 17 SEG G 16 SEG B 15 SEG F 14 SEG A 13 CLK MAX7219 DIN MAX7221
LOAD (CS) CLK GND GND 4 SEG A­G, SEG DP 8 SEGMENTS Pin Configurations appear at end of data sheet. ( ) MAX7221 ONLY DIP/SO ( ) MAX7221 ONLY 8-DIGIT P DISPLAY Functional Diagrams continued a …