MAX7219 - 8-Digit LED Display Driver, Serial I/F | Analog Devices
N.º da peça: MAX7219 ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $11.5 | $11,50 |
| 10 | $10.35 | $103,50 |
| 100 | $9.33 | $933,00 |
| 500 | $8.55 | $4.275,00 |
| 1.000 | $7.8 | $7.800,00 |
MAX7219 Visão geral
An LED display driver is a specialized interface IC that sits between a low-current logic controller (typically a microcontroller running at 3.3V or 5V CMOS levels) and high-current LED arrays. The driver integrates the BCD code-B decoder, multiplex scan circuitry, segment drivers, digit drivers, and an 8x8 static RAM that stores each digit state, removing the burden of bit-banging refresh from the host. In the broader taxonomy, the MAX7219 belongs to LED drivers -> display drivers -> power management & interface ICs -> semiconductors.
Key features of the MAX7219 include a 4-wire (SPI/QSPI/MICROWIRE-compatible) serial interface, individual digit addressing without rewriting the entire display, a 150 µA low-power shutdown mode (with the analog circuits still active), segment brightness modulation via duty-cycle control, and built-in scan limit and display-test registers. The device operates from a single 4.0V to 5.5V supply, sinks up to 40 mA per segment, and supports cascading via DOUT for larger displays.
The MAX7219 architecture uses an internal oscillator to multiplex the 8 digit lines sequentially while the on-chip static RAM holds the digit data, so the host only writes when content changes. This eliminates the CPU overhead typical of software-multiplexed LED designs and provides flicker-free, uniform brightness across all digits. The SPI-like interface accepts clock rates up to 10 MHz, allowing fast full-frame updates even for cascaded chains.
Typical applications include 8-digit 7-segment numeric readouts, 8x8 LED matrix modules (per MAX7219 channel), bar-graph meters, industrial control panel displays, point-of-sale terminals, instrumentation front panels, and hobby/maker 8-digit scrolling text displays. The same IC drives both 7-segment displays and bare discrete LEDs because each segment and digit line is independently accessible.
When designing with the MAX7219, choose the external resistor (ISET) carefully because it sets the segment current and therefore brightness; typical values are 9.53 kA for 20 mA segments or 47 kA for lower-current displays. Always include 0.1 µF and 10 µF decoupling caps close to V+ and GND, and use daisy-chained DOUT connections when more than 8 digits are needed. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Alternativas drop-in para MAX7219 — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
MAX7221CNG+
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX7221CWG+
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX7219CWG+
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX7219EWG
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX7219 Classificações máximas e características elétricas
| Display Type | Common-cathode LED (7-segment, bar-graph, or discrete LEDs) |
| Number of Digits Driven | Up to 8 digits or 64 individual LEDs |
| Interface | 4-wire serial (SPI/QSPI/MICROWIRE-compatible) |
| Frequência máxima de clock | 10 MHz |
| Supply Voltage (V+) | 4.0 V to 5.5 V |
| Shutdown Supply Current | 150 µA (analog sections remain active) |
| Faixa de temperatura de operação | 0 °C to +70 °C (commercial) / -40 °C to +85 °C (extended, package dependent) |
| On-Chip RAM | 8 x 8 static RAM for digit data |
| Cascade Capability | Yes (DOUT pin for daisy-chaining) |
| Internal Decoder | BCD code-B (also supports no-decode mode for raw LED control) |
| Display Test Register | Yes (forces all segments on) |
| Shutdown Mode | Yes (low-power shutdown, 150 µA) |
| Package Options | 24-pin PDIP (CNG), 24-pin SO (CWG), 24-pin CERDIP (EVKIT-grade) |
| Status RoHS | Compliant (SO package); CERDIP variant non-RoHS by construction |
| Lead-Free | Yes (lead-free finish available on SO and PDIP) |
Configuração de pinos do MAX7219
| Pino 1 | DIN — Serial data input |
| Pino 2 | CLK — Serial clock input |
| Pino 3 | CS — Chip select input |
| Pino 4 | GND — Ground (analog and digital) |
| Pino 5 | GND — Ground |
| Pino 6 | GND — Ground |
| Pino 7 | GND — Ground |
| Pino 8 | GND — Ground |
| Pino 9 | GND — Ground |
| Pino 10 | NC — Not connected |
| Pino 11 | NC — Not connected |
| Pino 12 | LOAD — Load data input |
| Pino 13 | DOUT — Serial data output (for cascading) |
| Pino 14 | SEG A — Segment A driver |
| Pino 15 | SEG B — Segment B driver |
| Pino 16 | SEG C — Segment C driver |
| Pino 17 | SEG D — Segment D driver |
| Pino 18 | SEG E — Segment E driver |
| Pino 19 | V+ — Positive supply voltage (4.0V to 5.5V) |
| Pino 20 | ISET — Segment current set (connect external resistor to V+) |
| Pino 21 | SEG F — Segment F driver |
| Pino 22 | SEG G — Segment G driver |
| Pino 23 | SEG DP — Decimal point segment driver |
| Pino 24 | DIG 7 — Digit 7 driver |
Aplicações típicas
MAX7219 é adequado para 7 aplicaçãos: 8-Digit 7-Segment Numeric Display Modules, 8x8 LED Matrix Display Modules, Industrial Bar-Graph Meter Displays, Point-of-Sale Terminal Numeric Displays, Test and Measurement Instrumentation Front Panels, Hobby / Maker Scrolling Text Displays, Automotive Dashboard Indicator Clusters.
8-Digit 7-Segment Numeric Display Modules
The MAX7219 is the de facto standard driver for hobby and industrial 8-digit 7-segment display modules. Its 8 on-chip digit drivers and 8 segment lines map directly to a single 8-digit common-cathode display, with the BCD code-B decoder eliminating per-digit firmware routines. Designers connect the 7-segment lines to SEG A–G and DP, the digit commons to DIG 0–7, and program segment current with one external ISET resistor (9.53 kΩ for ~20 mA segments). The 10 MHz SPI clock supports full-frame updates in microseconds, and the cascadable DOUT pin enables multi-digit readouts beyond 8 digits without bus reconfiguration.
Recomendado
8x8 LED Matrix Display Modules
The MAX7219 drives a single-color 8x8 LED matrix module directly, with each of the 8 digit lines sinking one matrix column and the 8 segment lines sourcing the matrix rows through current-limiting resistors. The on-chip multiplex scan eliminates the CPU overhead of bit-banged refresh, while the no-decode register mode (0x09) lets each row bit map directly to a segment line for arbitrary pixel graphics. Cascading two MAX7219s yields a 16x8 scrolling text display with only three microcontroller pins consumed on the SPI bus.
Recomendado
Industrial Bar-Graph Meter Displays
For analog-style bar-graph meters in industrial control panels, the MAX7219 drives up to 64 individual LEDs arranged as a vertical or horizontal bar graph with no external decoding required. The intensity register (0x0A) provides 32 brightness steps for ambient-light compensation, and the shutdown register (0x0C) drops quiescent current to 150 µA for battery-backed panels. Designers can chain two or more MAX7219s for 128-LED or 256-LED bar-graph readouts, mapping each LED to one bit of the digit RAM.
Recomendado
Point-of-Sale Terminal Numeric Displays
In POS terminals and electronic cash registers, the MAX7219 drives price, total, and quantity readouts with the BCD decoder handling the digit formatting automatically. The 4-wire SPI interface minimizes microcontroller pin usage, leaving more GPIOs available for keypad scanning and printer control. Cascading two or three MAX7219s allows long alphanumeric totals and product codes, while the 150 µA shutdown current is ideal for battery-backed systems that must retain the last display state across power cycles.
Recomendado
Test and Measurement Instrumentation Front Panels
Bench instruments such as multimeters, frequency counters, and lab power supplies use the MAX7219 to drive multi-digit numeric readouts with consistent brightness regardless of digit count. The on-chip scan oscillator and digit RAM guarantee flicker-free updates up to 800 Hz per digit, while the display-test register (0x0F) lets the MCU verify LED integrity at power-on. Designers benefit from the single-resistor segment-current programming, simplifying BOM and reducing calibration time during the assembly process.
Recomendado
Hobby / Maker Scrolling Text Displays
The MAX7219 powers the popular Arduino-based 8x8 dot-matrix and 8-digit scrolling text modules used in maker projects, digital clocks, and IoT status displays. Libraries such as LedControl and Parola abstract the SPI writes and provide text scrolling, animation, and brightness modulation. Cascading up to 8 MAX7219s on a single SPI bus supports long scrolling messages across 64x8 or 128x8 pixel panels, consuming only 3 microcontroller pins and running reliably on 5V USB power.
Recomendado
Automotive Dashboard Indicator Clusters
In automotive aftermarket dashboards and indicator clusters, the MAX7219 drives arrays of warning LEDs, gear-position indicators, and bar-graph tachometers with minimal microcontroller loading. The 4.0V–5.5V supply range tolerates regulated automotive 5V rails, and the cascadable interface allows multiple clusters to share one SPI bus. The shutdown mode reduces quiescent current to 150 µA during key-off, preserving battery life while the display content remains latched in the on-chip RAM.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para MAX7219 — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | MAX7221CNG+ | MAX7221CWG+ | MAX7219CWG+ | MAX7219EWG |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 24-PDIP (CNG) | 24-PDIP (CNG) - same | 24-SO Wide (CWG) | 24-SO Wide (CWG) | 24-SO Wide (CWG) |
| Supply Voltage | 4.0 V to 5.5 V | 4.0 V to 5.5 V | 4.0 V to 5.5 V | 4.0 V to 5.5 V | 4.0 V to 5.5 V |
| Max SPI Clock | 10 MHz | 10 MHz | 10 MHz | 10 MHz | 10 MHz |
| Digits / LEDs Driven | 8 digits / 64 LEDs | 8 digits / 64 LEDs | 8 digits / 64 LEDs | 8 digits / 64 LEDs | 8 digits / 64 LEDs |
| Serial Interface | 4-wire SPI/QSPI/MICROWIRE | 4-wire SPI/QSPI/MICROWIRE (Schmitt DIN) | 4-wire SPI/QSPI/MICROWIRE (Schmitt DIN) | 4-wire SPI/QSPI/MICROWIRE | 4-wire SPI/QSPI/MICROWIRE |
| Cascade Support (DOUT) | Yes | Yes | Yes | Yes | Yes |
| Operating Temperature Range | 0 °C to +70 °C | 0 °C to +70 °C | 0 °C to +70 °C | 0 °C to +70 °C | -40 °C to +85 °C (extended grade) |
| Shutdown Current | 150 µA | 150 µA | 150 µA | 150 µA | 150 µA |
Principais diferenciais
- 8-digit drive + 64-LED matrix in one chip with no CPU refresh overhead (vs MAX7219CWG+)
- Industry-standard 4-wire SPI at 10 MHz with cascading DOUT (vs MAX7221CNG+)
- Built-in BCD code-B decoder with no-decode raw LED mode (vs TM1637)
- Analog Devices active production with decades of design heritage (vs MAX7221EWG (extended temp variant))
Notas de projeto
Decouple V+ (pin 19) with both a 0.1 µF ceramic and a 10 µF electrolytic capacitor placed within 5 mm of the supply pin to suppress the digital switching transients generated by the multiplex scan oscillator. The MAX7219's internal multiplex can pull significant peak current when multiple digits are active in the same scan cycle; without adequate bulk capacitance the segment current can sag and cause visible brightness variation across digits. Ground pins 4–9 should all be tied to a single low-impedance ground plane, not separate traces.
A common mistake is omitting the external ISET resistor or using an incorrect value. The ISET resistor (typically 9.53 kΩ for 20 mA segments or 47 kΩ for low-current displays) programs the segment sink current; without it the segment drivers default to an undefined current that may damage the LEDs. Also avoid leaving unused digit lines floating - either connect them to GND through a resistor or disable them in the scan-limit register (0x0B) to prevent ghosting on adjacent digits.
When daisy-chaining multiple MAX7219s on a long SPI bus, add a 100 Ω series resistor at the host's CLK and DIN outputs to dampen ringing, and place a small capacitor (10–33 pF) at each MAX7219's CS pin to filter noise. The DOUT pin of the MAX7219 has limited drive strength, so for chains longer than 4 devices consider buffering the clock and data signals. Keep SPI traces short and routed over a continuous ground plane to avoid timing violations at the 10 MHz maximum clock rate.
Estimated: at full brightness with all 8 segments × 8 digits × 20 mA = 1.28 A peak current draw on V+, the MAX7219 in a 24-pin PDIP dissipates roughly 0.5–1 W depending on the multiplex duty cycle and supply voltage. The 24-pin PDIP thermal resistance is approximately 70 °C/W, leading to a 35–70 °C junction temperature rise above ambient. For enclosed or high-temperature installations, prefer the SO package variant (MAX22532-style SO with exposed pad option) for improved heat dissipation.
Informações de conformidade
RoHS and lead-free compliant per Analog Devices product page for SO and PDIP package options. CERDIP (military/aerospace grade) variants may not be RoHS by construction. Not AEC-Q100 qualified; choose MAX7219EWG for extended industrial temperature range, but verify with Analog Devices for automotive applications.
