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ROHM’s New ±1% Accuracy Current Sense Amplifier ICs Reduce

2023-03-09 | Return

Wide input voltage range (-0.2V to +26V) ideal for current sensing applications operating from 12/24V power supplies

ROHM has recently developed the space-saving, high accuracy current sense amplifier ICs (BD1421x-LA series) for industrial applications – including wireless base stations, PLCs and inverters – as well as consumer applications such as home appliances.

For some years the demand for current sensing is increasing in several applications. For example, high accuracy current sensing is required to improve motor rotation efficiency and to detect abnormalities. At the same time, smaller mounting area is required. However, conventional configurations (operational amplifier + discrete components) generally face challenges such as deterioration of current sensing accuracy due to variations in component accuracy and temperature characteristics. Also, it is difficult to keep the mounting area small.

In response, ROHM leveraged its strengths in analog technology to develop a new series of current sense amplifier ICs that achieves high accuracy current sensing in a space-saving design. The BD14210G-LA incorporates all required peripheral components. That simplifies current sensing by connecting a shunt resistor and a bypass capacitor. This reduces the number of components from eleven to just three compared to conventional configurations (operational amplifier + discrete components). Furthermore, it decreases the mounting area by 46% (SSOP6 package). Additionally, a highly accurate current detection of ±1% has been achieved over the entire temperature range (-40°C to +125°C). The internal circuitry prevents current detection accuracy to decrease even when an external RC filter circuit for noise suppression is added. That minimizes the number of man-hours required for design. The wide input voltage range (-0.2V to +26V) makes the BD14210G-LA ideal for current sensing applications operating from 12V/24V power supplies.

ROHM provides current sensing solutions that combine the new current sense amplifier ICs with an extensive lineup of shunt resistors. More support material, such as reference designs, are available. We also offer SPICE models that can be downloaded from ROHM’s website.

Product Lineup

In addition to the BD14210G-LA that is already in mass production, a total of 8 models are scheduled to be released. The lineup will include both 1 channel and 2 channels variants in four different gain settings (20, 50, 100, 200V/V).

Part No.	Supply Voltage V_DD [V]	Current Consumption I_DD [µA]	Common-Mode Voltage V_CM [V]	G_AIN [V/V]	Current Sense Accuracy [%]
BD14210G-LA	2.7 to 5.5	170	－0.2 to ＋26.0	20	±1.0 (Max.)
BD14211G-LA				50
BD14212G-LA				100
BD14213G-LA				200
BD14215FVJ-LA	2.7 to 5.5	310	－0.2 to ＋26.0	20	±1.0 (Max.)
BD14216FVJ-LA				50
BD14217FVJ-LA				100
BD14218FVJ-LA				200

☆: Under Development

Application Examples

• Industrial equipment: wireless base stations, PLC, inverters, chargers, etc.
• Consumer devices: air purifiers, refrigerators and more.

Reference Design

Support materials such as a reference design (REFSENS003) along with SPICE models are available on ROHM’s website.

Evaluation board information

Evaluation Board Part No: BD14210G-EVK-001

Terminology

PLC (Programmable Logic Controller)
A computer device that uses programs to control sequences and give commands to input/output devices.
It is often utilized in automatic control equipment in factories and for various machine controls.

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.

Reference Design
Data that can be used as a reference during circuit design.

Leaflet

High accuracy current monitoring contributes to improved application reliability.
Current Sense Amplifiers (CSAs)
BD1421xG-LA (1ch) / BD1421xFVJ-LA (2ch) series (PDF:1MB)

Source: http://www.rohm.com