Texas Instruments THS4120CDGNRG4

Overview

THS4120CDGNRG4 from Texas Instruments is a high-speed fully differential input/output amplifier optimized for single-supply 3.3 V operation, delivering 100 MHz –3 dB bandwidth, 55 V/µs slew rate, and –75 dB THD at 1 MHz with 2 VPP output-enabling precision differential ADC driving in data acquisition systems.

For engineers reviewing the THS4120CDGNRG4 datasheet, THS4120CDGNRG4 pinout, THS4120CDGNRG4 application, or THS4120CDGNRG4 equivalent, key selection considerations include power-down functionality (PD pin), VOCM-controlled output common-mode level, MSOP PowerPAD™ thermal performance, and differential distortion cancellation critical for high-fidelity signal chains.

Technical Context

The THS4120CDGNRG4 implements a true fully differential signal path from input to output using TI's submicron CMOS process, enabling balanced noise rejection and second-harmonic cancellation. Its internal architecture supports both differential-input/differential-output and single-ended-input/differential-output configurations with gain = 1 default.

It features an active power-down pin (PD) requiring a 10-kΩ pullup to VDD, reducing quiescent current from 13.5 mA to 120 µA; VOCM sets output DC level and accepts bypass capacitance for noise suppression. The device operates within ±1.5 V to ±1.75 V split or 3.0–3.5 V single supply, with specified performance over 0°C to 70°C (C-suffix).

Key Specifications

Pinout & Package

THS4120CDGNRG4 is housed in an 8-pin MSOP PowerPAD™ package (DGN), featuring an exposed thermal pad on the underside for enhanced heat dissipation. The PowerPAD must be soldered to a thermally conductive PCB copper plane to maintain junction temperature ≤125°C under continuous operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with THS4120CDGNRG4, THS4121CDGN removes power management overhead but increases static power, while THS4131CDGN trades lower noise floor and higher supply flexibility for reduced integration in 3.3 V–optimized designs.

Availability

THS4120CDGNRG4 is available at Aetrix Electronics and suitable for data acquisition systems, test instrumentation, and communications baseband circuits requiring stable component supply, long-term lifecycle support, and guaranteed authentic TI sourcing.

Supply support for THS4120CDGNRG4 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-speed amplifiers and precision signal chain solutions.

The THS4120CDGNRG4 belongs to TI's high-speed differential I/O amplifier family, designed specifically for low-voltage, high-fidelity ADC driving and differential signal transmission in space-constrained, thermally demanding applications.

FAQ

What is the function of the PD pin on the THS4120CDGNRG4?

The PD (Power-Down) pin on the THS4120CDGNRG4 is an active-high enable input that reduces quiescent current from 13.5 mA to 120 µA when driven below 1.2 V. For reliable operation, a 10-kΩ pullup resistor must connect PD to VDD; the device turns on when PD exceeds 1.4 V. THS4120CDGNRG4 does not enter high-impedance output state during power-down-the feedback network remains active, so output impedance is determined by external resistors.

How does the VOCM pin affect THS4120CDGNRG4 performance in ADC interface applications?

The VOCM pin on THS4120CDGNRG4 sets the common-mode voltage of both differential outputs, allowing precise alignment to an ADC's reference voltage (e.g., AVDD/2). When VOCM is left unconnected, it defaults to VDD/2 internally. For stability, TI recommends bypassing VOCM with a 0.1-µF capacitor to ground-this prevents noise injection and maintains THS4120CDGNRG4's specified CMRR and THD performance in real-world layouts.

Can THS4120CDGNRG4 drive capacitive loads, and what precautions are needed?

Yes, THS4120CDGNRG4 can drive capacitive loads, but direct connection risks instability due to its internal compensation optimized for bandwidth and slew rate. For loads >10 pF, TI specifies adding a 20 Ω series resistor at each output (VOUT+ and VOUT−) to isolate capacitance and preserve phase margin. This configuration prevents high-frequency ringing and ensures clean settling-verified in THS4120CDGNRG4's typical characteristics for RL = 800 Ω and CL = 100 pF.

What thermal design requirements apply to the THS4120CDGNRG4 MSOP PowerPAD™ package?

The THS4120CDGNRG4 uses an MSOP PowerPAD™ (DGN) package with an exposed thermal pad requiring solder attachment to a dedicated PCB copper pour. TI specifies θJA = 58.4°C/W when properly implemented; failure to connect the pad results in thermal runaway-junction temperature may exceed 125°C even at moderate power dissipation. Designers must follow SLMA002 guidelines: use thermal vias under the pad, connect to inner-layer ground planes, and avoid solder mask coverage on the pad surface.

Is THS4120CDGNRG4 compatible with split-supply operation, and what are the limits?

Yes, THS4120CDGNRG4 supports split-supply operation from ±1.5 V to ±1.75 V, as confirmed in the Recommended Operating Conditions table. In this mode, VDD connects to AVDD and GND connects to AVSS; VOCM must be biased within the common-mode input range (0.35 V to VDD – 0.1 V). All AC specifications-including 100 MHz bandwidth and –75 dB THD-are guaranteed under split-supply conditions, making THS4120CDGNRG4 suitable for legacy ±1.5 V systems alongside modern 3.3 V designs.