Texas Instruments THS4140CDGKR

Overview

THS4140CDGKR from Texas Instruments is a high-speed, fully differential input/output amplifier in an 8-pin MSOP PowerPAD™ package (DGK), delivering 160 MHz –3 dB bandwidth at ±15 V supply, 450 V/µs slew rate, and –79 dB third-harmonic distortion at 1 MHz - optimized for driving high-resolution differential ADCs in data acquisition systems.

For engineers reviewing the THS4140CDGKR datasheet, THS4140CDGKR pinout, THS4140CDGKR application, or THS4140CDGKR equivalent, this device supports single-ended-to-differential conversion, antialiasing filtering, and precision level-shifting with VOCM control - critical for signal integrity in 12–16-bit ADC interfaces, instrumentation front-ends, and high-fidelity analog signal chains.

Technical Context

The THS4140CDGKR implements a true fully differential signal path from input to output using TI's BiComI complementary bipolar process, enabling balanced rejection of common-mode noise at both input and output nodes. Its symmetrical architecture inherently suppresses second-harmonic distortion and improves PSRR and CMRR beyond conventional op-amps.

It features an active low shutdown pin (PD) that reduces quiescent current to 0.88 mA, placing outputs in high-impedance state (>1 MΩ) while preserving VOCM reference integrity. The VOCM pin sets output common-mode voltage with high bandwidth and supports direct connection to ADC reference outputs via 0.1 µF bypass capacitance.

Key Specifications

Pinout & Package

THS4140CDGKR is housed in an 8-pin MSOP PowerPAD™ (DGK) package with exposed thermal pad on underside - requires soldering to PCB copper pour for thermal management per TI SLMA002/SLMA004 guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with THS4141CDGKR and THS4131CDGKR, THS4140CDGKR uniquely combines 160 MHz bandwidth, active shutdown, and VOCM control - making it the only option among the three for power-aware, high-speed differential ADC driver designs requiring dynamic range extension and thermal management via PowerPAD™.

Availability

THS4140CDGKR is available at Aetrix Electronics and suitable for high-speed data acquisition, medical imaging front-ends, and communications baseband conditioning requiring stable component supply across industrial temperature ranges (–40°C to 85°C).

Supply support for THS4140CDGKR 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

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of innovation in high-performance amplifiers and data converters.

The THS414x family was designed specifically for precision, high-speed differential signal conditioning - targeting applications demanding low distortion, wide bandwidth, and robust common-mode rejection in ADC driver, instrumentation, and communications roles.

FAQ

What is the function of the PD pin on the THS4140CDGKR?

The PD (power-down) pin on the THS4140CDGKR is an active-low control that places the amplifier in low-power shutdown mode when pulled below ~1.4 V above VCC−. In shutdown, quiescent current drops to 0.88 mA and outputs enter a high-impedance state (>1 MΩ). Leaving PD unconnected defaults to active operation due to an internal 50 kΩ pull-up to VCC. THS4140CDGKR thus enables selective channel power gating in multi-channel systems without external switches.

How does the VOCM pin affect THS4140CDGKR output behavior?

The VOCM pin on the THS4140CDGKR directly sets the common-mode voltage of both differential outputs (VOUT+ and VOUT−). When driven externally (e.g., by an ADC's VREF), it aligns the output DC level to match the ADC's input range - eliminating level-shifting circuitry. If left unconnected, VOCM defaults to midrail (e.g., VCC/2 for single supply). A 0.1 µF bypass capacitor is mandatory to prevent noise coupling. THS4140CDGKR's VOCM input has high bandwidth, supporting fast common-mode transients without distortion.

Can THS4140CDGKR drive heavy capacitive loads, and what layout precautions apply?

THS4140CDGKR is not optimized for direct capacitive loading >10 pF due to reduced phase margin. To drive such loads (e.g., ADC input capacitance, long traces), a 20–50 Ω series resistor must be placed at each output (VOUT+, VOUT−) - isolating the amplifier from the capacitance while maintaining stability. Layout requires short, symmetric input traces; removal of ground plane under inputs/outputs; 0.1 µF ceramic + 6.8 µF tantalum decoupling per supply pin; and soldering the DGK package's PowerPAD™ thermal pad to a large copper pour for thermal reliability. THS4140CDGKR's performance degrades without these measures.

What is the maximum differential output voltage swing for THS4140CDGKR at ±15 V supply?

At ±15 V supply, THS4140CDGKR delivers a differential output voltage swing of ±12 V (24 VPP) under typical conditions (TA = 25°C, RL = 800 Ω). Over the full operating temperature range (–40°C to 85°C), the guaranteed minimum swing is ±11 V (22 VPP). This swing is referenced to the VOCM voltage - so actual VOUT+ and VOUT− swing symmetrically around VOCM. For example, with VOCM = 0 V, outputs swing from –12 V to +12 V differentially; with VOCM = 2.5 V, they swing from –9.5 V to +14.5 V. THS4140CDGKR maintains this performance across its specified load and frequency range.

How does THS4140CDGKR improve dynamic range compared to single-ended amplifiers?

THS4140CDGKR improves dynamic range by delivering a 2 VPP differential signal across two complementary outputs (e.g., +1 V and –1 V), whereas a single-ended amplifier would require 2 VPP swing on one node - often exceeding ADC input limits. This allows feeding a 2 VPP signal into a 1 VPP differential ADC input, effectively doubling usable signal swing without clipping. The symmetrical architecture also cancels even-order harmonics, improving SFDR and ENOB. THS4140CDGKR achieves this while maintaining 160 MHz bandwidth and <1% gain error - making it superior to cascaded single-ended solutions in size, noise, and distortion.