Analog Devices Inc./Maxim Integrated MAX49918IATB+T

Overview

MAX49918IATB+T from Analog Devices is a bidirectional, I²C-programmable current-sense amplifier with 8 discrete gain settings (10–200 V/V), ±1 µV typical input offset voltage, -5 V to +70 V input common-mode range, and rail-to-rail output. It enables high-precision, on-the-fly gain adjustment for battery current monitoring and H-bridge motor control in automotive and industrial power systems.

For engineers reviewing the MAX49918IATB+T datasheet, MAX49918IATB+T pinout, MAX49918IATB+T application, or MAX49918IATB+T equivalent, key selection criteria include programmable gain resolution, ±6 V to +80 V fault protection, 145 dB DC CMRR, 70 kHz bandwidth at G=20, and TDFN-10 package compatibility with space-constrained PCB layouts.

Technical Context

The MAX49918IATB+T implements a precision instrumentation amplifier core with digitally controlled gain via I²C register (address 0x00), supporting eight fixed-gain values without external resistors. Its dual reference inputs (REF1/REF2) configure unidirectional or bidirectional operation by setting output offset to GND, VDD, VDD/2, or an external reference.

It features integrated overvoltage protection on RS+/RS− pins (−6 V to +80 V), low 0.7 mA quiescent current, and operates across −40°C to +125°C. Gain switching settles within 25 µs, and input bias current remains below 150 nA over temperature.

Key Specifications

Pinout & Package

MAX49918IATB+T is housed in a 3 mm × 3 mm, 10-pin TDFN package (Package Code T1033+1C) with exposed pad (EP) internally connected to GND for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA240A1QDRQ1 and MAX40056ATA+T, the MAX49918IATB+T uniquely combines programmable gain, bidirectional operation, and high-voltage fault tolerance in a single 3 mm × 3 mm package-enabling flexible, variant-consolidated current sensing without hardware redesign.

Availability

MAX49918IATB+T is available at Aetrix Electronics and suitable for battery management systems, motor control modules, industrial power supplies, and high-reliability embedded sensing applications requiring stable component supply and long-term lifecycle support.

Supply support for MAX49918IATB+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

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The MAX49918IATB+T belongs to Analog Devices' precision current-sense amplifier portfolio, designed specifically for applications demanding programmable gain, wide common-mode range, and robust fault immunity in compact form factors.

FAQ

What is the maximum I²C clock frequency supported by MAX49918IATB+T?

The MAX49918IATB+T supports standard and fast-mode I²C operation up to 400 kHz. Its timing parameters-including tLOW (1.3 µs), tHIGH (600 ns), and tSU:DAT (100 ns)-are fully compliant with I²C Specification v3.0 at this rate. The device does not support high-speed mode (3.4 MHz). For reliable communication, ensure SDA/SCL rise/fall times remain ≤300 ns and use appropriate pull-up resistors based on bus capacitance.

Can MAX49918IATB+T be used for high-side current sensing in a 60 V automotive system?

Yes, MAX49918IATB+T supports high-side sensing in 60 V systems. Its guaranteed operational input common-mode range extends to +70 V, and its protective immunity reaches +80 V-covering ISO 7637-2 load-dump transients. When placed on the high side of a shunt, RS+ connects to the 60 V rail and RS− to the shunt's load side. Use REF1 = REF2 = VDD/2 to center the output for ADC interfacing, and confirm VDD is regulated to 3.3 V or 5 V independently.

How does the gain selection register work in MAX49918IATB+T?

The MAX49918IATB+T uses I²C register address 0x00 to set gain. Writing hex values 0x00 through 0x07 selects gains of 10, 20, 40, 50, 80, 100, 160, and 200 V/V respectively. The gain change takes effect within 25 µs. No configuration register write is required for power-up default (gain = 20 V/V). The A0 pin sets the LSB of the 7-bit I²C address (0xC4 or 0xC5), enabling dual-device addressing on one bus.

What is the purpose of REF1 and REF2 pins on MAX49918IATB+T?

REF1 and REF2 define the output reference voltage (VREF = (REF1 + REF2)/2) for the MAX49918IATB+T. Connecting both to GND yields ground-referenced unidirectional output; tying both to VDD gives VDD-referenced unidirectional output; setting REF1 = VDD and REF2 = GND creates mid-supply (VDD/2) referencing for bidirectional sensing. These pins must never be driven below GND or above VDD, and require low-impedance sources for accuracy.

Does MAX49918IATB+T require external passive components for basic operation?

Yes, MAX49918IATB+T requires a 0.1 µF ceramic bypass capacitor between VDD and GND, placed as close as possible to the VDD pin. I²C lines (SCL/SDA) need external pull-up resistors (typically 2.2 kΩ to VDD). No gain-setting resistors or compensation networks are needed-the amplifier is fully self-contained. The exposed pad (EP) must be soldered to a thermal pad connected to GND for optimal performance and thermal reliability.