The series includes three models with different gain settings: BD14230FVJ-C, BD14231FVJ-C and BD14232FVJ-C.
For lower voltage applications, the BD1422xG-C, available in the compact SSOP6 package, supports input voltages up to +40 V. This makes them suitable for automotive applications requiring space-saving designs, such as current (overcurrent) monitoring and protection in 5 V/12 V power networks used in body and transmission applications. Like its high-voltage counterpart, this series also consists of three different gain options: BD14220G-C, BD14221G-C, and BD14222G-C.
In recent years, alongside conventional 5V/12V power supplies, the automotive market has seen a growing adoption of 48V systems driven by the increasing popularity of electric vehicles. Furthermore, as vehicle functionality becomes more advanced, the need for precise monitoring and control across a wide range of applications continues to rise, making high-precision current sensing increasingly important.
A current-sensing amplifier indirectly measures the current flowing through a circuit by amplifying the minute voltage drop across a shunt resistor. The amplified signal is then sent to an ADC or comparator for system control and monitoring. ROHM's automotive current-sensing amplifiers meet market demands thanks to their proven analog expertise. This enables high-precision current sensing with compatibility for both negative and high-voltage environments, contributing to improved safety and reliability in automotive applications, particularly in electric vehicles.
These new products achieve greater space efficiency by integrating most of the current-sensing circuitry, typically consisting of an operational amplifier and discrete components, into a single package. As a result, current sensing is possible simply by connecting a shunt resistor. The devices also feature a two-stage amplifier configuration, consisting of a chopper amplifier at the input and a self-zeroing amplifier at the output. Internal resistor matching for gain adjustment ensures stable and accurate current sensing (±1%) while minimizing the effects of temperature variations.
Furthermore, the current detection accuracy is maintained even when an external RC filter circuit is added to suppress noise, significantly reducing design complexity and development time. Additional features include -14V negative voltage tolerance, which supports reverse electromotive force, reverse connection, and negative voltage input.
In the future, ROHM will continue to offer optimal solutions that contribute to greater precision and reliability in automotive equipment.
Product range
ROHM also offers the BD1421x-LA, a current sensing amplifier designed for applications in industrial equipment.
Application examples
• BD1423xFVJ-C (for 48 V systems): redundant power supplies, auxiliary batteries, DC-DC converters, and electric compressors, among others.
• BD1422xG-C (for 5 V/12 V systems): DCUs (domain control units) and ECUs (electronic control units) for vehicle bodies, etc.
The products (along with the evaluation boards) will be offered through other online retailers as they become available.
(Sales launch date: February 2025)
Expected sales products
