Analog Devices Inc./Maxim Integrated MAX9943ATT+T

Overview

The MAX9943ATT+T from Maxim Integrated is a single high-voltage, precision operational amplifier optimized for sensor signal conditioning and loop-powered industrial systems. It delivers 2.4MHz gain-bandwidth, 550μA supply current per amplifier, ±3V to ±19V dual-supply operation (or 6V–38V single supply), 100μV max input offset voltage, and rail-to-rail output swing - enabling accurate amplification in 4mA–20mA transmitter circuits.

For engineers reviewing the MAX9943ATT+T datasheet, MAX9943ATT+T pinout, MAX9943ATT+T application, or MAX9943ATT+T equivalent, this device is selected for high-precision, low-power, wide-supply-range analog signal conditioning where thermal stability across -40°C to +125°C and capacitive load tolerance up to 1nF are critical design requirements.

Technical Context

The MAX9943ATT+T employs a three-stage BiCMOS architecture optimized for low input offset voltage (≤100μV) and low input voltage noise density (17.6nV/√Hz at 1kHz), while maintaining unity-gain stability with up to 1nF capacitive load. Its input stage includes back-to-back diodes and series resistors for differential voltage protection up to ±40V.

It supports rail-to-rail output swing into 10kΩ loads (V_OH = V_CC − 0.2V, V_OL = V_EE + 0.1V), delivers 20mA output current, and achieves 105dB minimum CMRR and PSRR over its full operating temperature range (-40°C to +125°C).

Key Specifications

Pinout & Package

The MAX9943ATT+T is housed in a 3mm × 3mm, 6-pin TDFN-EP package with exposed pad (package code T633+2). The EP must be soldered to a large VEE plane for optimal thermal performance (θ_JA = 42°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage, precision op amp applications.

Compared with LT6015IMS8#PBF and OPA454AIDDA, the MAX9943ATT+T uniquely balances 2.4MHz bandwidth, 550μA supply current, 100μV offset, and full -40°C to +125°C operation - making it optimal for space-constrained, thermally demanding, loop-powered instrumentation where power and precision are co-constrained.

Availability

MAX9943ATT+T is available at Aetrix Electronics and suitable for 4–20mA transmitter design, high-voltage sensor signal conditioning, and automotive-grade industrial instrumentation requiring stable component supply across extended temperature ranges.

Supply support for MAX9943ATT+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and communications applications.

The MAX9943ATT+T belongs to Maxim's high-voltage precision op amp product line, engineered specifically for ruggedized industrial signal chains where low drift, wide supply range, and guaranteed operation from -40°C to +125°C are mandatory.

FAQ

What is the maximum capacitive load the MAX9943ATT+T can drive without oscillation?

The MAX9943ATT+T is unity-gain stable with capacitive loads up to 1nF, as confirmed in the Capacitive Load vs. Resistive Load graph and Electrical Characteristics table. This eliminates the need for external isolation resistors in most PCB trace and filtering applications. For loads exceeding 1nF, a series output resistor (e.g., 1.5kΩ) is recommended to restore phase margin, per Figure 1 in the datasheet. The MAX9943ATT+T's internal compensation ensures predictable stability behavior across its full operating temperature range.

Does the MAX9943ATT+T support true rail-to-rail input operation?

The MAX9943ATT+T supports rail-to-rail *output* swing but not rail-to-rail *input*. Its input common-mode voltage range extends to VEE (negative rail) but only up to VCC − 1.8V on the positive side, as specified in the Electrical Characteristics table. This means the noninverting input can accept signals down to VEE, but cannot reliably handle voltages within 1.8V of VCC. The MAX9943ATT+T's input protection circuitry (back-to-back diodes and series resistors) ensures robustness against overvoltage, but does not extend the functional input range beyond these limits.

What is the thermal performance of the MAX9943ATT+T in its 6-pin TDFN-EP package?

The MAX9943ATT+T in the 6-pin TDFN-EP package (T633+2) has a junction-to-ambient thermal resistance (θ_JA) of 42°C/W and junction-to-case (θ_JC) of 9°C/W when mounted on a four-layer PCB per JEDEC JESD51-7. Its exposed pad (EP) must be soldered to a large VEE copper plane to achieve these values. At TA = +70°C, the device dissipates up to 1904.8mW continuously (derated above +70°C at 23.8mW/°C). This thermal performance enables reliable operation in sealed enclosures or high-ambient industrial environments when layout guidelines are followed.

Can the MAX9943ATT+T operate from a single 24V supply?

Yes, the MAX9943ATT+T supports single-supply operation from 6V to 38V, so a 24V rail is fully within specification. In this configuration, VCC = +24V and VEE = GND (0V). The output swings rail-to-rail (0V to ~23.8V into 10kΩ), and the input common-mode range extends from 0V (VEE) to +22.2V (VCC − 1.8V). All DC and AC specifications - including 100μV max input offset, 2.4MHz GBWP, and 550μA supply current - are guaranteed across the full -40°C to +125°C range under single-supply conditions.

What is the short-circuit current limit and duration for the MAX9943ATT+T?

The MAX9943ATT+T short-circuit current limit depends on supply voltage and package. For the 6-pin TDFN-EP package (MAX9943ATT+T), the safe short-circuit duration is 60 seconds when VCC − VEE ≤ 20V (e.g., ±10V or +20V/GND), and only 2 seconds when VCC − VEE > 20V (e.g., ±15V or +30V/GND). This limitation is defined by thermal limits, not current magnitude - the device can deliver up to 100mA peak short-circuit current (TA = -40°C to +125°C), but sustained fault conditions require adherence to these time limits to prevent junction overheating. The MAX9943ATT+T's thermal shutdown is not integrated; safe operation relies on external fault management.