How the ANG101X reduces average power
Many battery operated systems are not active 100% of their time. Systems that deal with the real world and perform an action depending on the result of a sensor input often remain most of their time in an inactive sleep state and wake-up from time to time to take action and perform their job. Typical examples are wireless sensor nodes, health and safety systems, security and access control devices and HVAC applications.
The average power consumption of these kind of systems is defined by:
- the duty cycle between active and sleep mode
- the power consumption in active mode
- the sleep current
The first figure shows the simplified power profile for a wireless sensor node.
The ANG101x has been designed to help reduce the overall average system power consumption in three ways:
1. The power consumption in the active state is reduced (figure 2). The ANG101x allows the output voltages of the built-in DC-DC converter and LDO to be exactly tuned to the minimum supply voltage required by the other system components. The output voltages in both power domains can be dynamically, individually and efficiently converted down across a wide range and with a resolution of 50mV.
2. The system sleep current is reduced by completely switching off all the other system components in this state (figure 3). Critical timing functions for the duty cycle timing and for the real-time clock are performed by the ANG101x. Mission critical data is kept in the on-chip memory of the ANG101x.
3. The time that the system needs to be active can be reduced -and therefore also the total energy that is consumed during the active cycle- by performing certain tasks in the ANG101x while the system is in a sleep mode and the other system components are switched off. For example, measuring a sensor’s output and some other critical system parameters, is done completely autonomous by the ANG101x. The device is even able to make decisions by comparing the measured results against pre-programmed upper- and lower limits. Only when the measured results exceed these limits, the ANG101x will wake-up other system components and resume an active cycle. This function helps to eliminate unnecessary active cycles (figure 4).
The ANG101x helps you to achieve the lowest possible average power consumption for your system. It opens up the possibility to use alternative power resources such as the Photo Voltaic energy from a small (indoor) PV panel. E.g. for optimum scavenging of PV energy and storing the surplus energy in the most efficient way, the ANG1010 has a built-in boost converter with maximum power point tracking and supports energy storage in an external rechargeable battery of super capacitor.
The functionality that has been built-into the ANG101x will eliminate several other system components, including external power converters, A-to-D converter, one or more crystals, and will thus help reducing the total BOM cost.