MCUs target data-logging with dedicated LCD driver, PDF writer

March 15, 2017 // By Graham Prophet
Rohm Semiconductor, from its Lapis Semiconductor subsidiary, has announced 32bit microcontrollers for data loggers used in logistics for acquisition and management of environmental information during package shipment; the MCUs enable data-logging, LCD drive, and PDF generation for up to 1 year on a single coin battery

The ML630Q464/466 are positioned as the first ICs in the industry to integrate all major functions required for data logging (USB, high-speed clock generation, LCD driver, high-accuracy RC oscillation type AD converter), data acquisition (i.e. temperature, humidity, acceleration), data display, and PDF file generation, on a single chip.


For data loggers, which are typically attached to packages and in many cases disposable, it is important to reduce both size and cost by utilizing smaller batteries along with fewer parts. In addition, operating guidelines such as FDA*2 regulations on cold chain and GDP*3 require reliable recording of package conditions during transport and the output of uneditable PDF files to prevent tampering of records (log data).


Correspondingly, the ML640Q464/466 provide PDF file generation and integrate key functions for USB data logging on one chip with low power consumption, high noise immunity, and high performance. These new MCUs utilize an ARM Cortex M0+ core. Log data can be converted to PDF in about 4 seconds and operation is enabled for up to 380 days using a single coin battery. In addition, the products inherit Lapis Semiconductor’s robust noise immunity, making it possible to achieve stable operation even under severe conditions.


The ADC provides a temperature measurement accuracy of ±0.5℃ using only a thermistor and resistor/capacitor, unlike typical temperature measurement circuits consisting of a temperature sensor, thermistor, and reference voltage generation circuit. This reduces board space by 30% over conventional solutions.


An optimized PDF generation program is included within the IC that makes it possible to create a single A4 page PDF file with 2,500 measurement points in roughly 4 seconds. Also, combining the customer’s AES encryption program with the built-in AES function and random number generator allows users to generate password-protected PDF files.


These new MCUs achieve lowest standby current consumption of 0.8 µA by supporting four low power modes. As a result, operation for up to