Integrated Battery Voltage Sensor with High Voltage Isolation
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Solution Overview
Problem
Conventional battery voltage sensing systems for electric and hybrid vehicles face challenges in measuring individual cell voltages quickly and efficiently due to high component count, complex wire routings, and high current draw, which can cause EMI and slow down system speed.
Innovation Solution
An integrated circuit battery voltage sensor system utilizing two separate silicon dice with high voltage capacitors for isolation, a switching device for sampling and holding phases, and a signal generator for controlling the switching device, along with a buffer and optional filters for scaling and filtering the voltage signal, minimizes current draw and component count while ensuring high voltage isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a large sensing capacitor is used to minimize parasitic leakages, then measurement accuracy is improved, but charging current increases and system speed decreases
Solution Approach 1:
The patent introduces a voltage divider circuit as an intermediary between the battery and the sensing capacitor. This voltage divider scales down the battery voltage before it charges the sensing capacitor, allowing the use of a smaller capacitor that requires less charging current while still achieving accurate measurements through the scaled voltage relationship.
2Measurement precision
If a large sensing capacitor is used to minimize parasitic leakages, then measurement accuracy is improved, but system speed decreases
Solution Approach 1:
The voltage divider circuit acts as an intermediary that enables the use of a smaller sensing capacitor by pre-scaling the voltage. This smaller capacitor charges and discharges more quickly, improving system response speed while the voltage divider maintains measurement accuracy through its fixed division ratio.
Solution Approach 2:
The patent changes the voltage parameter through the voltage divider circuit, transforming the high battery voltage into a lower, scaled voltage that can be accurately measured by a smaller capacitor. This parameter transformation allows the system to achieve both speed and accuracy.
3Use of energy by moving object
If a transient current limiting resistor is added to limit charging current, then current draw is reduced, but system speed decreases due to low pass characteristic
Solution Approach 1:
The voltage divider circuit serves as an intermediary that reduces the voltage before it reaches the sensing capacitor, thereby reducing the charging current without requiring a large series resistor. This approach avoids the low-pass filtering effect that would slow down the system response.
4Reliability
If discrete solid-state relays are used for switching, then voltage isolation is achieved, but device complexity and wire routings increase
Solution Approach 1:
The patent merges multiple discrete components (solid-state relays, sensing capacitors, voltage dividers, and isolation circuits) into a single integrated circuit battery sensor. This integration maintains the necessary voltage isolation functionality while dramatically reducing component count and simplifying wire routings.
Solution Approach 2:
The integrated circuit performs multiple functions within a single device: voltage division, capacitance sensing, signal conditioning, and electrical isolation. This multi-functionality eliminates the need for separate discrete components for each function, reducing overall system complexity.
5Adaptability or versatility
If multiple solid-state relays are used for sensing and polarity correction, then measurement capability is improved, but device complexity increases
Solution Approach 1:
The integrated circuit combines multiple switching elements and sensing circuits into a unified structure, maintaining the capability to measure individual cell voltages and handle polarity corrections while reducing the visible component count to a single integrated device.
Solution Approach 2:
The integrated battery sensor provides universal functionality for voltage measurement, polarity detection, and correction within a single device, eliminating the need for separate discrete components for each measurement channel and correction function.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system enables faster sensing and output of scaled battery voltages with reduced component count and wire routings, minimizing current drawn from the batteries and achieving high voltage isolation, thus addressing the limitations of conventional methods.
Implementation Method 1
a voltage sensor configured to sample a voltage of a battery... The voltage sensor includes a first capacitor coupled to a positive potential terminal of the battery and a second capacitor coupled to a negative potential terminal of the battery
Implementation Method 2
a buffer in electrical communication with the voltage sensor and configured for scaling the sampled battery voltage and outputting a voltage signal proportional to the sampled battery voltage
Implementation Method 3
the voltage sensor is further configured for isolating the buffer from the battery... achieving high voltage isolation
Data Source
AI summary
An integrated circuit battery sensor and system thereof are provided. The battery sensor includes a voltage sensor configured to sample a voyage of a battery and a buffer in electrical communication with the voltage sensor and configured for scaling the sampled battery voltage and outputting a voltage signal proportional to the sampled battery voltage; wherein the voltage sensor is further configured for isolating the buffer from the battery. The voltage sensor includes a first capacitor coupled to a positive potential terminal of the battery and a second capacitor coupled to a negative potential terminal of the battery. The battery sensor includes a first die including a first and second input terminal configured for coupling to the positive and negative potential terminals of the battery; and a second die including the voltage sensor, wherein the first and second die are electrically isolated from each other.