EM6819 Ultra-Low Power Design Tips: Pushing Standby Current to nA
Understand the EM6819 power modes and use voltage, clock, and peripheral management to push standby current into the nA range and maximize coin-cell battery life.
Published: 2025-02-10
Understand the power modes
The EM6819 is an ultra-low power 8-bit MCU with Active, Standby, and Sleep states. What really decides battery life is usually not the Active current, but the standby/sleep current the device spends 99% of its time in.
In sleep mode the EM6819 can draw down to the nA range, so the design goal is simple: stay asleep as much as possible and wake only briefly when needed.
Keys to reducing standby current
A few practical rules: run the lowest VDD allowed (power scales with voltage); turn off every unused peripheral and analog block; and for long-running timekeeping, use a low-frequency RC or a 32kHz oscillator rather than the high-frequency main clock.
Also, drive every unused GPIO to a defined state (output low, or a weak pull) — floating pins leak and add hidden standby current.
LCD & peripheral power saving
The EM6819 has an integrated LCD driver, handy for always-on meters and electronic labels — but use its low-power display mode and lower the refresh rate. Power-hungry blocks like the ADC should be switched on only for the sampling instant and off immediately afterward.
Apply event-driven thinking throughout: wake on an interrupt or timer, do the work, and go straight back to sleep instead of polling.
Measure & validate
nA-level current needs the right tool — a current analyzer or source meter with wide dynamic range; an ordinary multimeter cannot read it accurately. Measure the Active and Sleep currents and their durations separately, then estimate the average current and battery life.
Validating that wake sources behave as expected and that the device returns to sleep cleanly (no block left enabled) is the key step that turns the theoretical power budget into real-world results.
Products mentioned
EM6819 Ultra-Low Power 8-bit MCU
The EM6819 is an ultra-low power 8-bit RISC microcontroller from EM Microelectronics. Built on CMOS process, it operates down to 0.9V and achieves nA-level sleep current. Features integrated LCD driver, timers, ADC, and rich peripherals — ideal for battery-powered consumer electronics and smart card applications.
Need these components or design help?
JLink Technology provides parts, datasheets, and engineering support.
Request a Quote