Current Sense Amplifier Design Guide and Application Examples

Current Sense Amplifier Design Considerations and Examples

In modern electronics, precision current monitoring is more than protection as it defines system efficiency and reliability. By selecting the right current sense amplifier, system designers can achieve real-time visibility of power behaviour, allowing effective circuit protection, efficiency optimisation and intelligent remote control across complex systems. Current sense amplifiers are divided into two types:

Digital type– providing complete voltage, current and power data and supporting I²C and SMBus interfaces, ideal for standby management and data analysis applications.
Analogue type– offering fast response and simple circuitry, well-suited for real-time feedback and protection functions.

To meet diverse design requirements, Richtek offers a comprehensive range of high-precision current sense amplifiers, including digital types RTQ6132 / RTQ6134 / RTQ6136、 RTQ6059 、 RTQ6053 / RTQ6056 , and analogue types RTQ6060A/RTQ6060B 、 RTQ6050/RTQ6052 . These devices cover a wide input voltage range and various accuracy levels, helping system designers quickly implement the most suitable power monitoring solutions.

Application Examples

Application	Description
Servers	In data centers, current sense amplifiers play a crucial role in power monitoring, energy optimisation and remote diagnostics. The RTQ6136, designed for 48 V systems, supports up to 75V AMR common-mode voltage, fulfilling high-reliability monitoring requirements.
USB Power Delivery (USB PD)	Accurate current monitoring ensures charging safety and optimised power efficiency.The RTQ6059 offers two address-select pins supporting up to 16 address options, ideal for multi-port PD systems managed by a single embedded controller.
PoE (Power over Ethernet)	Current sensing enables identification of PD type and power demand, allowing dynamic power allocation and preventing overload in multi-PD systems. The RTQ6056 , featuring a low-voltage detection function, is placed on the low-side to monitor PoE input and assist system control.
Desktop Computers	Real-time current monitoring enhances performance and reliability while reducing design risk. The RTQ6060 serves as the main power monitoring component, providing rapid current feedback to the embedded controller for instant system adjustment.

Current sense amplifiers have become an integral part of power management and system design. Richtek provides a complete portfolio of current sense amplifiers for more efficient and reliable systems.

See Application Note

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Digital CSA

Product Number	Common Mode Voltage Range	Maximum Offset	Maximum Gain Error	Input Sense Range	Package(s)
RTQ6136	0V to 60V	4µV	0.1%	Programmable	TWCSP-8P, TSOT-28
RTQ6134	0V to 60V	80µV	0.5%	Programmable	TWCSP-8P
RTQ6132	0V to 60V	40µV	0.3%	Programmable	TSOT-28
RTQ6059	0V to 32V	50µV	0.3%	Programmable	TSOT-23-8, MSOP-10
RTQ6056	0V to 36V	10µV	0.12%	Fixed	MSOP-10
RTQ6053	0V to 36V	25µV	0.3%	Fixed	VQFN-16L

Analog CSA

Product Number	Common Mode Voltage Range	Maximum Offset	Maximum Gain Error	Available Gain	Package(s)
RTQ6060A	0V to 36V	±35µV~±100µV	±0.4%	50V/V、75V/V、100V/V、200V/V、500V/V、1000V/V	SC-70-6
RTQ6060B	0V to 36V	±150µV	±0.8%	50V/V、75V/V、100V/V、200V/V、500V/V、1000V/V	SC-70-6
RTQ6052	2V to 80V	±2.5mV	±2%	100V/V	MSOP-8, SOP-8
RTQ6050	2V to 80V	±2.5mV	±2%	20V/V	MSOP-8, SOP-8

For consumer applications, we also offer the RT6050 、 RT6052 、 RT6053 and RT6056 .

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Current Sense Amplifier Design Considerations and Examples：PoE, USB PD, Desktop and Server Applications

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