075582814553
Heart rate and blood oxygen monitoring have become essential features in modern wearable and portable health devices. This article will discuss the MAX30100 sensor and module overview, pinout details, internal components, features, specifications, application circuits, interfacing methods, and common applications.
The MAX30100 Heart Rate and Oxygen Pulse Sensor is a compact biometric sensor developed by Maxim Integrated for measuring heart rate (HR) and blood oxygen saturation (SpO₂). It is commonly used in wearable and portable health-monitoring devices.
This sensor integrates red and infrared LEDs, a photodetector, and low-noise analog signal processing into a single package. Using the photoplethysmography (PPG) principle, it detects changes in light absorption caused by blood flow and oxygen levels to calculate accurate pulse and SpO₂ readings.
Designed for low power consumption, the MAX30100 is suitable for battery-powered applications such as fitness trackers, smartwatches, and medical prototypes. It supports I²C communication, allowing easy integration with microcontrollers like Arduino and ESP32.
If you are interested in purchasing the MAX30100, feel free to contact us for pricing and availability.
| Pin No. | Pin Name | Description |
| 1 | N.C. | No connection |
| 2 | SCL | I²C serial clock input |
| 3 | SDA | I²C serial data input/output |
| 4 | PGND | Power ground for LED drivers |
| 5 | IR_DRV | Infrared LED driver output |
| 6 | R_DRV | Red LED driver output |
| 7 | N.C. | No connection |
| 8 | N.C. | No connection |
| 9 | R_LED+ | Red LED anode connection |
| 10 | IR_LED+ | Infrared LED anode connection |
| 11 | VDD | Power supply input |
| 12 | GND | Ground |
| 13 | INT | Interrupt output |
| 14 | N.C. | No connection |
| Pin Name | Description |
| VIN | Power supply input for the module. Typically operates at 3.3 V. Some breakout boards may support 5 V via onboard regulation. |
| SCL | I²C Serial Clock pin used for communication with a microcontroller (Arduino, ESP32, etc.). |
| SDA | I²C Serial Data pin used to transfer data between the MAX30100 sensor and the controller. |
| INT | Interrupt output pin. Goes low when new heart rate or SpO₂ data is available. Optional but useful for power-efficient designs. |
| IR | Connection to the infrared LED driver, used mainly for heart rate and oxygen saturation measurement. |
| RD | Connection to the red LED driver, primarily used for SpO₂ (blood oxygen) detection. |
| GND | Ground reference for power and signal return. |
The MAX30100 module is a compact biosensing board designed for heart rate and blood oxygen (SpO₂) measurement. Below are its main components and their functions:
• MAX30100 Sensor IC – The core chip that integrates red and infrared LEDs, a photodetector, and analog front-end circuitry to measure pulse rate and blood oxygen saturation.
• Red LED (660 nm) – Emits red light used for SpO₂ measurement by analyzing oxygenated and deoxygenated hemoglobin absorption.
• Infrared LED (940 nm) – Works with the red LED to improve accuracy in heart rate and oxygen level detection.
• Photodiode – Detects reflected light from blood vessels and converts it into an electrical signal for processing.
• Voltage Regulator – Ensures stable operating voltage for the sensor, protecting it from fluctuations when connected to microcontrollers.
• Pull-up Resistors (I²C) – Used on the SDA and SCL lines to support reliable I²C communication.
• Decoupling Capacitors – Filter noise and stabilize power supply lines for accurate signal acquisition.
• Header Pins – Provide easy connection to microcontrollers like Arduino, ESP32, or Raspberry Pi for power and data transfer.
• Pulse 3+
• Proto Central AFE4490
• ROHM BH1792GLC
• FSH 7060
• Texas Instruments AFE4404
• Texas Instruments AFE4950
• Silicon Labs Si1143
• AMS AS7038RB
• Maxim MAX86140
• MAX30102
• MAX30101
• MAX30105
The MAX30100 system block diagram shows how the sensor measures heart rate and blood oxygen (SpO₂) using optical sensing. When a finger is placed on the cover glass, red and infrared (IR) LEDs shine light into the skin. This light passes through blood vessels, where part of it is absorbed by hemoglobin depending on oxygen levels and blood volume changes.
Reflected light from the tissue is received by the photodiode. The amount of returned red and IR light varies with each heartbeat and with the ratio of oxygenated (HbO₂) and deoxygenated hemoglobin (Hb). These tiny light changes carry the physiological information needed for pulse and SpO₂ calculation.
Inside the chip, the analog signal from the photodiode is converted into digital data by the ADC. The control and signal-processing blocks manage LED timing, noise reduction, and data formatting. The processed output is then sent to a microcontroller, where heart rate and oxygen saturation values are calculated and displayed.
| Parameter | Specification |
| Sensor Type | Pulse oximeter and heart-rate sensor |
| Measured Parameters | Heart rate (BPM), Blood oxygen saturation (SpO₂) |
| Optical Components | Red LED (660 nm), Infrared LED (940 nm), Photodiode |
| LED Peak Wavelengths | Red: 660 nm, IR: 940 nm |
| Communication Interface | I²C |
| I²C Address | 0x57 (default) |
| Supply Voltage (VCC) | 1.8 V (core), 3.3 V / 5 V (module level with regulator) |
| LED Driver Current | Programmable up to 50 mA |
| ADC Resolution | 16-bit |
| Sampling Rate | 50–1000 samples per second (programmable) |
| Operating Temperature | −40 °C to +85 °C |
| Power Consumption | Low-power, optimized for wearable devices |
| Package (IC) | Optical module (integrated LEDs and photodiode) |
| Compatible Platforms | Arduino, ESP8266, ESP32, Raspberry Pi |
The MAX30100 combines the red LED, infrared LED, light sensor, and signal-processing circuit into one small chip. Because everything is already built in, designers do not need many extra parts. This makes the circuit easier to design, saves board space, and reduces overall cost. Its very small size is ideal for wearable devices like fitness bands and health monitors.
The MAX30100 is designed to use very little power, which is important for battery-powered devices. The sampling speed and LED current can be adjusted so the sensor only uses as much power as needed. When the sensor is not active, it consumes extremely low current, helping devices last much longer between charges.
The sensor is built to produce clean and stable signals, even when the user moves. It can reduce errors caused by hand movement and outside light, which improves heart rate and oxygen level readings. Its fast data output also allows real-time monitoring, making it suitable for medical and fitness applications.
The sensor measures heart rate and blood oxygen levels using light. The device uses two power supplies: 3.3 V for driving the red and infrared LEDs and 1.8 V for its internal analog and digital circuits. Decoupling capacitors are added to keep the power stable and reduce noise, which helps ensure accurate readings.
The red (660 nm) and infrared LEDs shine light into the skin, and the reflected light changes with blood flow and oxygen saturation. This reflected light is detected by the built-in photodiode. The signal then passes through ambient light cancellation and the analog front end, where unwanted light and noise are removed before the signal is converted to digital data by the ADC.
Inside the sensor, digital filtering further cleans the signal before the data is stored in internal registers. The processed heart rate and SpO₂ data is sent to a microcontroller through the I²C interface, using pull-up resistors for reliable communication. An interrupt pin can signal when new data is ready, helping reduce power consumption.
Catalogue
FPGA / CPLD
Memory
MOS 
MCU 
DSP
OCEP
Secondary 
Other