BETADisplay capacity8 digits / 64 LEDs
Eight-digit serial LED driver
MAX7219 Specifications
Review MAX7219 electrical specifications, operating conditions and package details.
Package view
Key specifications
Eight display bytes remain in internal RAM. A scan engine selects one digit at a time, and the segment drivers supply the requested anodes. Brightness combines the RSET current setting with intensity PWM.
Operating supply4.0–5.5 V
Serial clock10 MHz maximum
PWM levels16 intensity settings
Package details
MAX7219ENG+ · PDIP-24
| Property | Details |
|---|---|
| Manufacturer | Analog Devices |
| Part number | MAX7219ENG+ |
| Package | PDIP-24 |
| Connections | 24 pins |
| Mounting | Through-hole |
| Lead pitch | 2.54 mm |
| Package code | PDIP-24 |
| Thermal reference | See operating and package limits |
Supply and logic levels
Recommended operating conditions
Manufacturer specifications 7 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| V+ operating range | 4.0–5.5 V | Example uses regulated 5 V |
| Input HIGH / LOW | ≥3.5 V / ≤0.8 V | DIN, CLK and LOAD; 3.3 V is not a guaranteed HIGH |
| Shutdown current | 150 µA typical | 25°C, logic inputs at a supply rail |
| Display refresh | 800 Hz typical at eight digits | 500–1300 Hz specified scan range |
| Selected E temperature grade | −40 to +85°C | C grade is 0–70°C |
| Bypass capacitors | 100 nF ceramic + 10 µF bulk | Close to V+19 and ground |
| Ground contacts | Pins 4 and 9 | Connect both; carry multiplexed display return current |
No specifications match. Try a parameter name or a unit.
Check power dissipation separately from the temperature grade.
Registers and command words
16 bits, MSB first: address byte then data byte
Manufacturer specifications 8 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| 0x00 · No-op | Data ignored | Use to pass a command through a daisy chain |
| 0x01–0x08 · Digits | One display byte each | Addresses correspond to DIG0–DIG7 |
| 0x09 · Decode mode | One bit per digit | 1 enables Code B; 0 selects raw segments |
| 0x0A · Intensity | Low nibble 0x0–0xF | 16 PWM settings |
| 0x0B · Scan limit | 0–7 | Selects one through eight scanned digits |
| 0x0C · Shutdown | 0=blank / 1=normal | RAM and control contents retained |
| 0x0F · Display test | 0=normal / 1=all LEDs | Overrides shutdown and intensity; disable after testing |
| Unused command bits | D15–D12 ignored | D11–D8 address; D7–D0 data |
No specifications match. Try a parameter name or a unit.
MAX7219 has no readback register command. DOUT is the serial shift output.
Decode and segment mapping
Digit data is interpreted by the decode mask
Manufacturer specifications 7 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Raw D7…D0 | DP, A, B, C, D, E, F, G | A set bit lights its segment during that digit slot |
| Code-B values 0x0–0x9 | Numerals 0–9 | Lower nibble selects the glyph |
| Code-B 0xA…0xF | −, E, H, L, P, blank | D4–D6 ignored |
| Decimal point | D7=1 | Independent of Code-B decoding |
| Raw numeral 8 | 0x7F | All seven bars on; decimal point off |
| Raw blank | 0x00 | All segments off |
| Decoded blank | 0x0F | Use only on Code-B-enabled digits |
No specifications match. Try a parameter name or a unit.
A raw matrix image needs decode mode 0x00.
Current, PWM and heat
Do not confuse peak and average LED current
Manufacturer specifications 8 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Eight-digit example RSET | 64.9 kΩ | Near the 63.7 kΩ manufacturer-table value for 10 mA at 2.0 V LED drop |
| Maximum recommended peak | 40 mA per segment | Check LED pulse rating and IC power budget |
| Minimum RSET | 9.53 kΩ | Actual current also depends on LED forward voltage |
| Intensity code k | PWM duty = (2k+1)/32 | k=0…15; applies during each digit slot |
| Per-LED average at eight digits | Approximately Ipeak × PWM duty / 8 | Multiplexing is in addition to intensity PWM |
| One / two / three digits | Peak ≤10 / 20 / 30 mA | Manufacturer limits individual digit-driver dissipation |
| Package thermal resistance | PDIP: 75°C/W; SOIC: 85°C/W | Datasheet reference values; board and cooling matter |
| Current example | 10 mA × 15/32 ÷ 8 ≈0.586 mA | Intensity code 7; approximate average per lit LED |
No specifications match. Try a parameter name or a unit.
Use scan limit for the real display topology; use intensity to dim.
Serial timing and cascading
LOAD is a latch strobe on MAX7219
Manufacturer specifications 7 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Serial clock maximum | 10 MHz | At least 50 ns HIGH and 50 ns LOW |
| DIN setup / hold | 25 ns / 0 ns | Relative to CLK rising |
| LOAD HIGH pulse | At least 50 ns | Latch after the last bit |
| LOAD rise to next CLK rise | At least 50 ns | MAX7219 requirement |
| DOUT progression | 16.5 clock cycles behind DIN | Updates on falling CLK edges; always driven |
| Chain connection | DOUT → next DIN | Share CLK and LOAD; send farthest-device word first |
| MAX7221 distinction | CS gates clocking; outputs slew-limited | Do not assume those behaviors for MAX7219 |
No specifications match. Try a parameter name or a unit.
Use a defined idle clock and latch only after a complete transfer.
Eight-digit startup example
Example values for decoded numbers
Manufacturer specifications 8 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Blank during setup | 0x0C, 0x00 | Shutdown while configuring |
| Disable test | 0x0F, 0x00 | Avoid the all-on override |
| Enable Code B | 0x09, 0xFF | All eight digits decoded |
| Select eight digits | 0x0B, 0x07 | DIG0 through DIG7 |
| Set moderate PWM | 0x0A, 0x07 | 15/32 slot duty |
| Initialize display RAM | 0x01…0x08 with 0x0F | Blank every decoded digit |
| Write a zero on DIG0 | 0x01, 0x00 | Use 0x80 to include its decimal point |
| Enable display | 0x0C, 0x01 | Normal scanning begins |
No specifications match. Try a parameter name or a unit.
Commands are two bytes each, followed by LOAD rising.
Connections by function
Select a pin for its function, connection guidance and electrical notes.