ALLPCB
Standalone LCD Glucose Meter
Component Summary
| Part Number | VDD | IO/ADC | TIMER | ROM/RAM/EEP | CLOCK | Interface | Others | Package | ||
|---|---|---|---|---|---|---|---|---|---|---|
| HT45F65 | 2.2V~5.5V | 37/12-bit×8 | 3 | 8K/256/- | 4/8/12MHz HIRC | SPI/I2C, UART, SPIA | LCD driver, OPA, DAC, Temp sensor, Audio DAC | 48/64 LQFP | ||
| HT45F66 | 59/12-bit×8 | 4 | 16K/512/- | 64/80 LQFP | ||||||
| HT45F67 | 32K/512/- | |||||||||
| BH66F2450 | 39/12-bit×4 | 4 | 8K/256/64 | LED driver, OPA, DAC, MDU, OVP | 48 LQFP | |||||
| BH66F2470 | 39/12-bit×4 | 32K/512/64 | ||||||||
| ? | BH67F2470 | 46/12-bit×4 | 32K/768/64 | LCD/LED driver, OPA, DAC, MDU, OVP | 64/80 LQFP |
HCT Glucose Meter (Hematocrit Measurement)
Design reference: No. WAS-199c
Component Summary
| Part Number | VDD | IO/ADC | TIMER | ROM/RAM/EEP | CLOCK | Interface | Others | Package | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ? | BH67F2485 | 2.2V~5.5V | 44/24-bit×6 | 4 | 48KW/4KB/128B | 4/8/12/16 MHz | SPI/I2C, SPIA, UART | MDU, OPA, DAC, IAP, LCD driver, Phase detect | 64/80 LQFP |
Applications
Glucose meters, lactate meters, and other devices that use LCD displays.
Key integrated features: precise DAC, LCD drive, and operational amplifiers suitable for current sensing and voltage excitation.
Low power and low component count: integrated ADC, DAC, OPA, and display drivers reduce external components.
Technical Overview
Accurate glucose monitoring is essential for diabetes management. Holtek provides MCUs combining 12-bit ADC, precise DAC, operational amplifiers, and integrated LCD drivers that are applicable to glucose and lactate meters. These MCUs support precise excitation voltages and I/V conversion using operational amplifiers, ADCs for analog-to-digital conversion, and LCD display support for result presentation.
HCT measurement is implemented using electrochemical methods that measure DC current from blood and enzyme reactions, as well as AC impedance and phase angle. The BH67F2485-based design integrates phase-angle and electrochemical measurement analog front-end circuitry. Using a high-precision DC excitation voltage, current measurements estimate glucose concentration. AC impedance and phase measurements at different frequencies and excitation amplitudes enable HCT estimation, which is used to compensate glucose readings across the full HCT range. Phase measurement accuracy is about ±0.3° and impedance accuracy is about ±1%.
Technical files such as block diagrams, circuit schematics, PCB layouts, and bill of materials are provided with the reference designs.
