High-Side, Current-Sense Amplifiers with 12-Bit ADC and Op Amp/Comparator

Description

Maxim introduced the MAX9611/MAX9612, the latest additions to its industry-leading portfolio of high-side, current-sense amplifiers. Designed for industrial, consumer, and automotive applications that require digitized current-sense data, the MAX9611/MAX9612 integrate a 12-bit ADC and a gain block that can be configured as either an op amp or a comparator. This integration provides the key components for easy implementation of fault monitoring and closed-loop control applications, such as inrush-current limiting and gain control.

The high-side, current-sense amplifiers operate over a wide 0V to 60V input common-mode voltage range. The programmable full-scale voltage (440mV, 110mV, and 55mV) of these amplifiers offers wide dynamic range, accurate current measurement, and application flexibility in choosing sense resistor values. A choice of either an internal op amp or a comparator is provided to the user. The internal amplifier can be used to limit the inrush current or to create a current source in a closed-loop system. The comparator can be used to monitor fault events for fast response.

An I²C controlled 12-bit, 500sps analog-to-digital converter (ADC) can be used to read the voltage across the sense resistor (VSENSE), the input common-mode voltage (V_RSCM), op-amp/comparator output (V_OUT), op-amp/comparator reference voltage (V_SET), and internal die temperature. The I²C bus is compatible with 1.8V and 3.3V logic, allowing modern microcontrollers to interface to it.

The MAX9611 features a noninverting input-to-output configuration while the MAX9612 features an inverting input-to-output configuration.

The MAX9611/MAX9612 operate with a 2.7V to 5.5V supply voltage range, are fully specified over the –40°C to +125°C automotive temperature range, and are available in a 3mm x 5mm, 10-pin µMAX® package.

An evaluation kit is available: MAX9611EVKIT.

Key Features

• 0V to +60V Input Common-Mode Voltage Range
• 2.7V to 5.5V Power-Supply Range, Compatible with 1.8V and 3.3V Logic
• 5µA Software Shutdown Current
• Integrated 12-Bit ADC
• 13µV Current-Sense ADC Resolution
• 500µV (max) Current-Sense ADC Input Offset Voltage
• 0.5% (max) Current-Sense ADC Gain Error
• I²C Bus with 16 Addresses
• Small, 3mm x 5mm 10-Pin µMAX Package
• –40°C to +125°C Operating Temperature Range

Applications/Uses

• Base-Station Feeder Cable Bias-T
• Base-Station PA Control
• Battery-Operated Equipment
• Hybrid Automotive Power Supplies
• Server Backplanes
• Telecom Cards

Typical Application Circuit

Key Specifications

Part Number	CMVR (V)		VCC (V)		ICC (µA)	VSENSE_FS (mV)	VOS@25°C (µV)	Gain Accuracy @25°C (%)	BW (kHz)	Oper. Temp. (°C)	Package/ Pins
	min	max	min	max	recomm.	max	@–3dB
MAX9611	0	60	2.7	1600	No	300	Adj.	4000	1	–40 to +125	µMAX/10
MAX9612