Richtek Newsletter
Richtek Newsletter   Sep. 27, 2018 | Newsletter Issue 29
What is RT1025 Cardioid PAD?
The RT1025 Cardioid PAD is Richtek's first integrated ECG (Electrocardiography) and PPG (Photoplethysmography) AFE (Analog Front End) solution for heart-rate monitoring and measurements. It measures ECG and PPG signals simultaneously, transmitting the high-precision raw data processed from 24 bits ADC to a mobile phone via its built-in Bluetooth module. After downloading high-precision ECG and PPG raw data onto a PC, designers can create algorithms for data processing to obtain physiological information such as heartbeat, blood pressure, blood oxygen, etc. which is ideal for product development for both consumer and medical applications.

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How does it work?
The RT1025 Cardioid PAD has three electrodes, used to create a measurement loop with your heart. By pressing your fingers on the electrodes, you can monitor both ECG and PPG waveforms and save all measurement raw data after activating Cardio EVK APP.
But how do we use ECG and PPG data to calculate blood pressure and blood oxygen? For blood pressure, we need to calculate PTT (Pulse Transit Time) which is inversely proportional to blood pressure. PTT is the time it takes for a signal to propagate through a length of the arterial tree, meaning we can estimate PTT from measuring both ECG and PPG signals travelling from the heart to the testing points. Blood oxygen is calculated by using the absorption ratio of human hemoglobin to red light and near-infrared light. The PPG measurement circuit on the Cardioid PAD transmits both light signals to human body. Designers can calculate blood oxygen by using algorithm to proceed optical signal raw data. Please have a look at the video to see a measurement demonstration and further explanation.
 Read more for ECG measurement circuit     Read more for PPG measurement circuit 
The RT1025 integrates low noise voltage and current sensing channels and is capable of sensing both ECG and PPG simultaneously. It features a low standby current (less than 7µA), housed in a 3.1mm x 3.4mm ultra-small CSP package. It has 24-bit high-precision ADC designed for processing ECG signals and 16-bit ADC for measuring PPG signals. In addition, with over 85dB high CMRR(common-mode rejection ratio), it can achieve good noise cancellation.

RT1025 meets IEC60601-2-27 medical electrical equipment standard and China’s YY 1079 specification, which makes it ideal for medical as well as fitness and wearable applications, such as ECG tablets, ECG bracelets, ECG chest stickers, ECG rings, etc.

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Please have a look at the video where you can find a RT1025 Cardioid PAD measurement demonstration and additional product details.
What we offer
Richtek provides a highly integrated RT1025 Cardioid PAD development platform including hardware and software, the exclusive Cardio EVK mobile APP, which can effectively help designers quickly develop products. If you already have your own development kits but are looking for ECG and PPG measurement ICs, you can purchase RT1025 ICs or RT1025 daughter boards to work with your own platform. Please check below for product and purchase information or contact us.
RT1025 Datasheet | Cardioid EVK APP
Free Samples | RT1025 EVB | Cardioid PAD
Application Note
The system design example below shows where/how RT1025 can be used. Richtek has a wide variety of power solutions for IoT/Portable/Wearable/Battery-Powered Applications. Please click the diagram below to download our latest product selection guide.

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Wearable device function block
6Vin CMCOT Synchronous Buck Converter Family
     1A IOUT, 1MHz, with Power Good in WDFN2x2-6 package          RT5710F
     1A IOUT, 1.5MHz, with Power Good in (T)SOT-25(6) packages RT8096A      RT8096B
RT8096C      RT8096D
     1A IOUT, 1.5MHz in WDFN2x2-6 packages RT5710A      RT5710B
RT5710C      RT5710D
     1A IOUT, 1MHz, with Power Good in (T)SOT-25(6) packages RT5796A      RT5796B
RT5796C      RT5796D
     1A IOUT, 1.5MHz in WDFN2x2-6 packages RT5711A      RT5711B
     2A IOUT, 1MHz, with Power Good in (T)SOT-25(6) packages RT8097A      RT8097B
RT8097C      RT8097D
     2A IOUT, 1MHz in WDFN2x2-6 packages RT5712A      RT5712B
     2.5A IOUT, 1MHz with Power Good in SOT-26 package          RT8098D
     3A IOUT, 1MHz with Power Good in WDFN2x2-8(S) packages RT5797A      RT5797B

Remark: Fast transient:(A)PSM/PWM / (B)Force-PWM; Medium transient:(C)PSM / PWM (D)Force-PWM

Check out the products that meet your area of interest for more information
RT1025 RT1025 is an integrated AFE solution for Heart-Rate monitoring and measurements in a 3.1mm x 3.4mm, 41-Ball, 0.4mm pitch, WL-CSP package. Integrating low noise voltage and current sensing channels, it is capable of sensing ECG (Electrocardiography) and PPG (Photoplethysmography) simultaneously. The RT1025 solution only requires few discrete components and is easy to use for low-power medical ECG/PPG, sports, and fitness applications.

  Free samples
  Buy from distributors
  RT1025 daughter boards for purchase

RTQ2569-QA RTQ2569-QA is an automotive AEC-Q100 Grade 1 qualified, 2µA IQ, 0.2A, 3.5V-36V input, 2.5V-12V output, Low Dropout Voltage Linear Regulator in a WDFN3x3-8 package. Featuring short circuit protection and thermal operation, RTQ2569-QA is suitable for automotive applications, portable battery-powered equipment, extra-low voltage microcontrollers etc.

  Find out more

RT5797A RT5797A is a 3A, 2.7V-6V input, 0.6V-3.4V output, 1MHz, CMCOT Synchronous Buck Converter in a WDFN2x2-8(S) package. The CMCOT operation with internal compensation allows the transient response to be optimised over a wide range of loads and output capacitors. It is ideal for STBs, LCD TV power supply & metering platforms, networked communication, etc.

  Free samples
  Buy from distributors

RT9089A RT9089A is a sink/source tracking termination regulator in a WDFN2x2-10 package. It supports remote sensing functions and all features required to power the DDRI / DDRII / DDRIII and Low Power DDRIII / DDRIV VTT bus termination according to the JEDEC specification.

  Buy from distributors