IDT’s battery sensor ICs accurately determine the charge condition of the battery based on inputs including charge and discharge currents, battery voltage, temperature, and aging. Both voltage and current are measured with two highly linear, synchronous 24-bit analog-to-digital converters.
Battery Charge Measurement in Automotive Applications
Measuring charge and discharge currents is particularly challenging as the battery monitoring IC must be capable of precisely measuring milliampere currents when the engine is turned off and up to more than one thousand amperes when the engine is started. IDT’s battery sensor ICs can achieve this requirement by means of a shunt-resistor-based current measurement technique combined with a highly dynamic embedded programmable gain amplifier.
Another challenging requirement is for ultra-low power consumption in standby mode, for example when a vehicle is parked. The battery sensor IC must continue to monitor the battery’s state even when the engine is turned off. In this standby mode, IDT’s battery sensing ICs typically consume only 55 to 60 μA.
IDT’s Battery Sensing ICs Enable Energy Efficiency
Due to the urgent global need to reduce environmental pollution and to meet governmental regulations limiting maximum harmful emission from vehicles, automotive companies are increasing their efforts to introduce features aimed towards reducing fuel consumption. One of these highly effective fuel saving features is the start-stop system, which automatically shuts down and restarts the engine as needed to reduce the amount of time the engine spends idling, thereby reducing fuel consumption and emissions by as much as 5 to 10 percent. In order to ensure a safe re-start of the engine once it has been turned off, precise information on the charge condition of the starter battery is essential.
Battery Sensing ICs with Internal and External Microcontrollers
IDT offers two product lines for battery sensing ICs: one for external microcontrollers and a more advanced line with an integrated 32-bit ARM© Cortex™ based microcontroller. Leading-edge ICs with an internal microcontroller are preferred for small form-factor, standalone intelligent battery monitoring systems. Our battery sensing ICs for use with external microcontrollers are preferred for solutions that are embedded in systems that already contain a microcontroller or where one master controller controls several battery monitoring slaves, such as in multi-battery applications or systems requiring additional safety via redundant measurement of battery current. IDT’s ICs with an internal microcontroller offer effective intellectual property safeguarding for customer software by employing copy protection for the user’s firmware on the chip.