Analog Devices Inc./Maxim Integrated MAX9938TEBS+T

Overview

MAX9938TEBS+T from Maxim Integrated is a unidirectional high-side current-sense amplifier in a 4-bump UCSP (1mm × 1mm) package, featuring 25V/V fixed gain, ±500μV max input offset voltage, <0.5% max gain error, and ultra-low 1μA max quiescent supply current. It operates with input common-mode voltage from +1.6V to +28V and delivers precision current monitoring in battery-powered portable systems where minimal voltage drop and nanoscale footprint are critical.

For engineers reviewing the MAX9938TEBS+T datasheet, MAX9938TEBS+T pinout, MAX9938TEBS+T application, or MAX9938TEBS+T equivalent, key selection criteria include its 25V/V gain configuration, 1μA supply current for ultra-low-power operation, 1.6V–28V common-mode range enabling direct battery-voltage sensing, and compatibility with sub-50mV full-scale sense voltages for low-loss current measurement.

Technical Context

The MAX9938TEBS+T uses a BiCMOS-based high-voltage p-channel FET architecture to force current through matched internal gain resistors (R1 and ROUT), achieving precise proportional output voltage VOUT = I_LOAD × R_SENSE × ROUT/R1. Its input stage accepts common-mode voltages up to +28V without external level-shifting, eliminating need for isolated supplies.

It features built-in 6V output clamping and 7mA typical output current limiting for robustness against overdrive. The device is stable with any external capacitive load and supports Kelvin-sense PCB layouts to mitigate trace resistance errors in high-current paths.

Key Specifications

Pinout & Package

MAX9938TEBS+T is packaged in a 4-bump, 1mm × 1mm × 0.6mm UCSP (Ultra-Compact Silicon Package) with bottom-side solder bumps. This RoHS-compliant, lead(Pb)-free package supports fine-pitch PCB assembly and thermal performance suitable for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side current-sense amplifier applications.

Compared with MAX9938TEBS+T, INA219AIDR trades analog simplicity and nanopower for integrated digitization and higher supply current, while MAX40056AUT+T offers lower offset and higher gain at the cost of increased quiescent draw and reduced flexibility in sense-resistor sizing.

Availability

MAX9938TEBS+T is available at Aetrix Electronics and suitable for smartphone battery monitoring, notebook power management, portable medical device safety verification, and IoT sensor node energy accounting requiring stable component supply, consistent parametric performance, and long-term lifecycle support.

Supply support for MAX9938TEBS+T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated, now part of Analog Devices, designs precision analog, mixed-signal, and power-management ICs for demanding industrial, automotive, and portable applications.

The MAX9938 product line delivers nanopower, high-accuracy current sensing for battery-operated systems where size, quiescent current, and measurement fidelity are non-negotiable design constraints.

FAQ

What is the exact package type and dimensions of MAX9938TEBS+T?

MAX9938TEBS+T uses a 4-bump UCSP (Ultra-Compact Silicon Package) measuring 1.0mm × 1.0mm × 0.6mm with bottom-side solder bumps. It is RoHS-compliant and marked with top code "+AGD". This package is distinct from the SOT23-5 and μDFN variants offered in the same MAX9938 family, and MAX9938TEBS+T specifically corresponds to the UCSP version with 25V/V gain.

Does MAX9938TEBS+T require an external power supply pin?

No, MAX9938TEBS+T has no dedicated VCC pin. Its supply is derived from the input common-mode voltage applied across RS+ and RS−, which must be between +1.6V and +28V. The device draws current only from the RS+ and RS− pins, with total supply current ≤1μA over temperature. This architecture eliminates the need for auxiliary regulators and simplifies power-domain isolation in MAX9938TEBS+T implementations.

What is the maximum full-scale sense voltage supported by MAX9938TEBS+T at 3.6V supply?

At a minimum RS+ voltage of 3.6V, MAX9938TEBS+T supports up to ~120mV full-scale V_SENSE while maintaining linear output swing. This is calculated from V_OUT(max) ≈ V_RS+(min) − V_SENSE(max) − V_OH (0.2V), yielding V_SENSE(max) ≈ (3.6V − 0.2V)/25 = 136mV, with 120mV recommended for margin. MAX9938TEBS+T's ±500μV offset ensures <0.5% error at this level.

Can MAX9938TEBS+T be used in bidirectional current sensing applications?

MAX9938TEBS+T is unidirectional and optimized for high-side sensing of current flowing from RS+ to RS−. For true bidirectional measurement, two MAX9938TEBS+T devices can be used-one sensing forward current and one sensing reverse-with separate OUT connections referenced to GND. However, dedicated bidirectional amplifiers like MAX40016 offer integrated dual-output architectures not present in MAX9938TEBS+T.

What is the output impedance and settling behavior of MAX9938TEBS+T?

MAX9938TEBS+T has a nominal output resistance of 10kΩ (7–13.2kΩ range) and settles to 1% of final value in ≤100μs for a 50mV step input. Its output is voltage-mode and compatible with standard SAR or delta-sigma ADC inputs. The device remains stable with any capacitive load, including 100nF ceramic filters used to suppress sampling transients-no external compensation is needed for MAX9938TEBS+T.