Source: https://mokxi.com/parts/cd4511 Updated: 2026-11-10 Part # CD4511 7-segment driver Four wires in, one lit digit out. See every part - 16 pins - 1 setting - In 1 project - In 1 lesson Drawn live by the editor's own code, at the size you see it. At a glance ## The CD4511 7-segment driver in brief What it is, and every setting the properties panel gives it. The CD4511 is the 16-pin CMOS BCD to seven-segment decoder: a number from 0 to 9 in binary on A (the 1s bit) to D (the 8s bit) lights segments a to g of a common-cathode display, with no code. LT (lamp test) and BI (blanking) are active low and LE latches the digit, so tie LT and BI to VDD and LE to VSS for a display that follows its inputs. VDD takes 3 to 18 volts. From an Uno, four digital pins drive A to D directly; from an ESP32, run VDD at 3.3 volts too. Mokxi models the 4511’s own font, with no tails on 6 and 9 and codes 10 to 15 blank, and the outputs as emitter followers, VDD less 0.6 volts behind 35 ohms, so every segment still needs a resistor. Delays follow the data sheet, 640 nanoseconds to light at 5 volts, and the model property offers the much faster 74HC4511. The classic mistakes are a floating LT, BI or LE, and a common-anode display, which never lights. Latch setup and hold times, and damage from a missing resistor, are not modeled. Family Logic Pins 16 model CD4511B (or 74HC4511) Pins ## 16 pins Named as the editor names them, so a wire lands where you expect it. ### Input7 - B - C - LT - BI - LE - D - A ### Input or output2 - VSS - VDD ### Output7 - e - d - c - b - a - g - f How to use it ## How to use the CD4511 decoder with an Arduino Give the chip 5 V on VDD and ground on VSS, tie LT and BI to 5 V and LE to ground, and wire a to g to the segments of a common-cathode display. Then a number from 0 to 9 in binary on A (worth 1), B (2), C (4) and D (8) shows as that digit. The circuit here sets the four bits with a DIP switch; from an Arduino, four digital pins do the same job with digitalWrite(). The outputs source current from VDD less about 0.6 V, so a segment still needs a resistor; this circuit cheats with one 100 ohm resistor in the display’s common, and a 1 is visibly brighter than an 8. Codes 10 to 15 blank the display, and the 6 and 9 have no tails. A floating LT, BI or LE is the fault everybody hits. Part pin Board pin VDD 5 V VSS GND LT, BI 5 V LE GND A, B, C, D DIP switches 1, 2, 3 and 4 a to g Display segments a to g With VDD at 3.3 V an ESP32’s outputs drive A to D directly; the chip runs from 3 to 18 V. Click to open it in the editor This is the simulator itself, running here. Click anything to open it in the editor. Open this project in the editor Read the full tutorial How it is modeled ## What is true about the CD4511 7-segment driver, here In its help article’s own words: what the simulation gets right, and where it stops. ### Modeled The outputs source current. Each segment output is an NPN emitter follower that can source up to 25 mA, so a high output sits about 0.6 V under VDD and sags a little more under load: the model is VDD minus 0.6 V behind 35 ohms, a straight line through the MC14511B data sheet's typical output voltages from 5 to 25 mA. A low output is only the weak CMOS pull-down, as on the 4017. A segment still needs a series resistor, typically 330 ohms to 1 k at 5 V. Delays come from the data sheet, per path and direction. At 5 V: 640 ns for a segment to light and 720 ns to go out after a data change; 600 and 485 ns after blanking changes; about 310 ns after lamp test changes. They shorten with the supply (250 and 290 ns for data at 10 V) and are interpolated in between. An unknown input only clouds the segments it could change. With A, B and C low and D floating, the code is 0 or 8, which differ only in segment g: every other segment is known and lit, and only g shows as unknown. ### Not modeled No setup or hold time on the latch. No current limit on the outputs and no damage from running a segment without a resistor; the only thing limiting the current then is the 35 ohms of the model. Below 5 V the delays are held at the 5 V figures. Common-anode displays need a different chip (the 4543 or a 74HC247) and will not light from this one, as on the bench. From CD4511 seven-segment driver, in full. Projects ## See the CD4511 7-segment driver in a project One built-in project uses it. It opens in the editor, already wired. Lessons ## Where it turns up in a lesson One lesson places it in its own circuit. ### Learn articles 1 lesson - BCD to 7 Segment Decoder: CD4511 Truth Table, Live More parts ## The rest of the bench Every one of these is drawn and simulated the same way. Full-size breadboard A real 0.1 inch grid with the rails and the center channel, 63 columns wide. Jumper wires Drag from any pin or hole to any other. Corners snap, and you can drag them. Power A supply rail at the voltage you choose. Ground The other end of every circuit. LED Lights when current flows. Five colors, and the brightness is what your eye would see. Filament lamp A tungsten bulb in a holder: an inrush when it is switched on cold, tens of milliseconds to warm up, and dim on half its voltage. Resistor Any value you like, with the color bands drawn to match. ESP32-C3-DevKitM-1 A RISC-V board that runs your firmware at 160 MHz on the real memory map. Pushbutton A 12 mm tactile switch. Hold it while the simulation runs. Raspberry Pi Pico The RP2040 board on our own Cortex-M0+ core. Pick a program and press Run. Raspberry Pi Pico W Raspberry Pi Pico W (RP2040). The same board and the same pinout as a Pico, with the CYW43439 on it. The WiFi is simulated (no radio; real internet through the Cloud panel’s switch), and the on-board LED, which hangs off that chip rather than off GP25, is driven through the same path. Everything else is the Pico. Raspberry Pi 4 Model B Raspberry Pi 4 Model B: the 40-pin header, driven by main.py with RPi.GPIO or gpiozero. See every part ## Wire up the CD4511 7-segment driver Open the editor and push it into the breadboard. It is free, and it runs on your own machine. Start building free Open the editor