Generally IoT devices are composed of sensors, microcomputers, and communication ICs. Power management ICs are necessary in order to supply power to these components.

The battery capacity needs to be large enough to extend the battery life of IoT devices, but the space and the weight of IoT devices are limited.

In order to extend the battery life and to maintain the miniaturization and light weight of IoT devices, it is necessary to set small supply current as much as possible.

Power management IC contributes to battery life

Achieves a long service life of battery with a nano-order low supply current

Ricoh's low supply current power management IC for IoT devices achieves very small supply current such as several hundreds of nA at no operation and a few to tens of nA at Standby mode.

If the current consumption is a few mA at Active mode, and around a few µA at Standby mode, Ricoh's Nano-order supply current IC contributes to reduce the whole system power consumption.

Battery-life calculating tool
How long does the battery of your product last? Check it out with this tool!

Battery-life calculating tool

Inputting the following five parameters enables to simply calculate and provide an indication of the battery life.

Battery capacity

mAh

Current at intermittent operation

At standby

µA

At active

Time of the intermittent operation

At standby

At active

The battery lasts

days.

The battery life varies by temperature, humidity, and a type of battery. This is an estimation under an ideal environment.

Timing chart: Supply current

A lower-limit value of input voltage affecting the battery life

Other than the supply current, the battery life is highly affected by the lower-limit value of input voltage. Since the battery voltage gradually decreases while the battery is being used, the battery can be used longer as the lower-limit value of the input voltage is low.

As an example, discharging characteristics of button cell (CR2032) indicate the following characteristics having voltage drop with gradient. IoT devices often operate intermittently; the following characteristics in red line indicate a strong gradient of voltage drop due to the pulse load is applied on the button cell.

Discharging characteristics of button cell (CR2032)

Discharging characteristics of button cell (CR2032)

Ex.) Power management IC, RP512

As for the RP512, the lower-limit value of input voltage is 2.0 V. The battery can last 75% longer than the 2.4 V-product at the intermittent operation using button cell.

The consideration of the lower limit value of input voltage is also important as well as the supply current for longer battery life.