Analog Devices Inc. LT1997IDF-1#PBF

Overview

LT1997IDF-1#PBF from Analog Devices is a precision, high-voltage, gain-selectable difference amplifier optimized for bidirectional current sensing in industrial power systems. It integrates a matched resistor network and precision op amp to deliver 0.012% gain error (G=10), 109dB CMRR, and operation with input voltages up to V– + 76V - enabling robust high-side sensing in 48V/60V bus applications.

For engineers reviewing the LT1997IDF-1#PBF datasheet, LT1997IDF-1#PBF pinout, LT1997IDF-1#PBF application, or LT1997IDF-1#PBF equivalent, key selection criteria include guaranteed 1ppm/°C gain drift, rail-to-rail output swing, 350µA quiescent current, shutdown mode (20µA), and DFN14 package compatibility with space-constrained motor drives and battery management systems.

Technical Context

The LT1997IDF-1#PBF implements a fully integrated difference amplifier architecture with three dedicated noninverting/inverting input pairs (+INA/–INA, +INB/–INB, +INC/–INC) for pin-selectable gains of 10, 20, and 50. Its internal op amp operates in both normal and Over-The-Top® (OTT) modes, supporting common-mode inputs from V– to V– + 76V independent of V+.

Gain configuration relies on internal precision thin-film resistors (15kΩ, 7.5kΩ, 3kΩ) with <1ppm/°C matching TC and <2ppm nonlinearity. The REF pin enables level-shifting output to match downstream ADC reference levels, while SHDN provides logic-controlled low-power state activation.

Key Specifications

Pinout & Package

LT1997IDF-1#PBF is housed in a 14-lead (4mm × 4mm) plastic DFN package with exposed thermal pad (Pin 15 = V–). The package supports high-density layout and efficient heat dissipation (θ_JA = 45°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar difference amplifier applications.

Compared with INA240A1IDR and AD8417BRMZ, the LT1997IDF-1#PBF offers unique pin-selectable gain, REF-based level shifting, and superior CMRR (107dB vs ≤100dB), making it optimal for precision bidirectional sensing where design flexibility and noise immunity are critical.

Availability

LT1997IDF-1#PBF is available at Aetrix Electronics and suitable for industrial motor drives, battery management systems, and programmable logic controller (PLC) analog input modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LT1997IDF-1#PBF 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 LT1997-1 product line delivers precision, high-voltage difference amplifiers with integrated resistor networks for current sensing and level translation in harsh industrial environments - designed to replace discrete op amp + resistor solutions with guaranteed matching and temperature stability.

FAQ

What is the maximum input common-mode voltage for LT1997IDF-1#PBF?

The LT1997IDF-1#PBF supports an input common-mode voltage range from V– to V– + 76V, independent of the V+ supply voltage. This allows direct high-side sensing on 60V industrial buses without external level-shifting circuitry. Operation beyond V– + 76V is not guaranteed and may degrade performance or cause damage.

How do I configure LT1997IDF-1#PBF for gain-of-50 operation?

To configure LT1997IDF-1#PBF for gain-of-50, connect the signal source across +INC and –INC pins. These pins route directly to internal 3kΩ resistors forming the gain-setting network. All other input pins (+INA, –INA, +INB, –INB) must remain unconnected or grounded per the datasheet to avoid loading effects. No external components are required.

Does LT1997IDF-1#PBF support bidirectional current sensing?

Yes, LT1997IDF-1#PBF supports true bidirectional current sensing. When configured with REF biased at mid-supply (e.g., 2.5V for 5V system), the output swings symmetrically above and below REF to indicate direction. Its rail-to-rail output and low offset (65µV max) enable accurate zero-crossing detection for regenerative braking and H-bridge control.

What is the thermal pad connection requirement for LT1997IDF-1#PBF?

The exposed pad (Pin 15) of LT1997IDF-1#PBF is electrically connected to V– and serves as the primary thermal path. It must be soldered to a PCB copper pour tied to the system ground plane. Minimum recommended solder stencil aperture is 80% of pad area; insufficient thermal connection risks junction temperature exceeding 150°C under sustained 50mA output load.

Can LT1997IDF-1#PBF operate from a single 3.3V supply?

Yes, LT1997IDF-1#PBF operates from a total supply voltage of 3.3V to 50V, including single-supply configurations. With V+ = 3.3V and V– = 0V, it maintains full functionality: G=10 CMRR ≥104dB, gain error ±0.017%, and rail-to-rail output swing. Input common-mode range remains V– to V– + 76V, but practical limits apply based on internal op amp headroom (V– to V+ – 1.75V in normal mode).