ROHM has developed a new lineup of high accuracy current sense amps – the BD1423xFVJ-C and the BD1422xG-C. They are qualified under the AEC-Q100 automotive reliability standard. The BD1423xFVJ-C series, offered in the TSSOP-B8J package, supports input voltages up to +80V, making it ideal for high-voltage environments such as 48V DC-DC converters, redundant power supplies, auxiliary batteries, and electric compressors. The series includes three models with different gain settings: BD14230FVJ-C, BD14231FVJ-C and BD14232FVJ-C.
For lower voltage use cases, the BD1422xG-C, available in the compact SSOP6 package, supports input voltages up to +40V. This makes them suitable for automotive applications requiring space-saving designs, such as current monitoring and protection (overcurrent) in 5V/12V power supply networks used in body and drivetrain domains. 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 fueled by the rising 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 increase, placing a greater importance on high-accuracy current sensing.
A current sense amp indirectly measures the current flowing through a circuit by amplifying the miniscule 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-grade current sense amps meet market demands by leveraging proven analog expertise. This enables high-accuracy current sensing with compatibility for both negative and high voltage environments, contributing to improved safety and reliability in automotive applications, particularly electric vehicles.
These new products achieve greater space efficiency by integrating most of current sensing circuitry, typically comprised of an operational amplifier and discrete components, into a single package. As a result, current detection is possible by simply connecting a shunt resistor. The devices also feature a two-stage amplifier configuration, consisting of a chopper amplifier at the input and an auto-zero amplifier at the output. Internal resistor matching for gain setting ensures stable, accurate current sensing (±1%) while minimizing the effects of temperature variations.
Furthermore, current detection accuracy is maintained even when an external RC filter circuit added for noise suppression, significantly reducing design complexity and development time. Additional features include -14V negative voltage tolerance that supports back electromotive force, reverse connection, and negative voltage input.
Going forward, ROHM will continue to deliver optimal solutions that contribute to higher precision and enhanced reliability in automotive equipment.
Product Lineup
ROHM also offers the BD1421x-LA of current sense amps designed for industrial equipment applications.
Application Examples
• BD1423xFVJ-C (for 48V systems): Redundant power supplies, auxiliary batteries, DC-DC converters, and electric compressors, and the like
• BD1422xG-C (for 5V/12V systems): Body DCUs (Domain Control Units) / ECUs (Electronic Control Units), etc.
Online Sales Information
Availability: May 2025 (OEM quantities)
Pricing: $3.00/unit (samples, excluding tax)
Online Distributors: DigiKey and Mouser
The products (along with evaluation boards) will be offered at other online distributors as they become available.
(Sales Launch Date: February 2025)
Target Sales Products
Terminology
AEC-Q100 Automotive Reliability Standard
AEC stands for Automotive Electronics Council, a reliability standard for automotive electronic components established by major automotive manufacturers and US electronic component makers. Q100 is a standard that specifically applies to integrated circuits (ICs).
Shunt Resistor
A resistor connected in series in the current path to detect the current in the circuit by measuring the potential difference across it.
Chopper Amp
An amp circuit designed to minimize signal offset and noise, primarily used for accurately amplifying low-frequency and weak DC signals.
Auto-Zero Amp
An amp that automatically compensates for offset voltage (unwanted noise and errors) by continuously sampling and correcting it during operation. This ensures high signal accuracy, making it ideal for applications that demand ultra-precise measurement and signal processing.
