My Inquiry
My Account
Texas Instruments THS4121CDGNR
- Part No.:
- THS4121CDGNR
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width) Exposed Pad
- Datasheet:
-
THS4121CDGNR.pdf
- Description:
- IC OPAMP DIFF 1 CIRCUIT 8HVSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,419
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
THS4121CDGNR from Texas Instruments is a single-channel, fully differential-input/differential-output high-speed amplifier optimized for driving precision ADCs in single-supply 3.3 V systems. It delivers 100 MHz –3 dB bandwidth, 55 V/µs slew rate, –75 dB THD at 1 MHz (2 VPP), 5.4 nV/√Hz input voltage noise, and operates with VOCM pin for output common-mode level control - enabling transformerless interface to differential analog-to-digital converters.
For engineers reviewing the THS4121CDGNR datasheet, THS4121CDGNR pinout, THS4121CDGNR application, or THS4121CDGNR equivalent, key selection criteria include differential ADC driver performance under 3.3 V supply, VOCM-controlled output centering, balanced output noise rejection, and MSOP PowerPAD™ thermal management requirements.
Technical Context
The THS4121CDGNR implements a true fully differential signal path from input to output, supporting both differential-input/differential-output and single-ended-input/differential-output configurations. Its internal architecture enables balanced output swing, intrinsic second-harmonic cancellation, and high common-mode rejection (96 dB typical) without external trimming.
It features a dedicated VOCM pin that sets the DC common-mode level of both outputs independently of gain configuration, with high bandwidth up to the amplifier's operating range. The device lacks power-down functionality (unlike THS4120), simplifying bias control but requiring continuous quiescent current management (13.5 mA typical at 3.3 V).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| –3 dB Bandwidth | 100 MHz - supports wideband signal conditioning up to ~30 MSPS ADC sampling with adequate small-signal fidelity. |
| Slew Rate | 55 V/µs - ensures accurate reproduction of fast transient signals without slewing-induced distortion in 2 VPP applications. |
| Total Harmonic Distortion | –75 dB at 1 MHz, 2 VPP - meets high-fidelity requirements for 14-bit+ ADC drivers where spectral purity is critical. |
| Input Voltage Noise | 5.4 nV/√Hz at 10 kHz - low enough to avoid dominating noise floor in medium-bandwidth precision acquisition chains. |
| Common-Mode Rejection Ratio | 96 dB (typical) - rejects coupled noise on differential inputs, preserving signal integrity in noisy mixed-signal PCB environments. |
| Supply Voltage Range | 3.3 V single supply - eliminates need for dual rails while maintaining rail-to-rail compatible output swing via VOCM control. |
| Quiescent Current | 13.5 mA (typical) - defines thermal load in compact layouts; requires thermal pad connection per PowerPAD™ guidelines. |
Pinout & Package
The THS4121CDGNR is housed in an 8-pin MSOP PowerPAD™ package (DGN), featuring an exposed thermal pad on the underside for enhanced heat dissipation. The thermal pad is electrically isolated and must be soldered to a PCB copper pour for reliable thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN− | Inverting input | Differential input node; matched impedance critical for CMRR and harmonic cancellation. |
| VOCM | Output common-mode control | Sets DC level of both outputs; bypass with 0.1 µF capacitor to suppress noise coupling. |
| VDD | Positive supply | 3.3 V single supply input; requires local 0.1 µF ceramic + 6.8 µF tantalum decoupling. |
| VOUT+ | Positive differential output | Provides inverted complement of VOUT−; together forms low-noise, balanced 2 VPP output pair. |
| VIN+ | Non-inverting input | Differential input node; symmetry with VIN− essential for distortion performance. |
| NC | No connect | Unbonded pin; must remain unconnected per TI design - no routing or grounding. |
| GND | Analog ground reference | Return path for supply and signal currents; requires low-inductance connection to solid ground plane. |
| VOUT− | Negative differential output | Provides inverted complement of VOUT+; phase-matched to VOUT+ for common-mode noise rejection. |
Key Features
| Feature | Design Value |
|---|---|
| Fully differential I/O architecture | Enables true differential signaling end-to-end, doubling dynamic range versus single-ended amplifiers for same ADC input range. |
| VOCM-controlled output centering | Allows precise alignment of differential output common-mode to ADC reference voltage (e.g., AVDD/2), eliminating level-shifting circuitry. |
| High CMRR and PSRR | 96 dB CMRR and 85 dB PSRR minimize sensitivity to PCB layout noise and supply ripple in mixed-signal systems. |
| Optimized for 3.3 V single supply | Operates across full industrial temperature range (0°C to 70°C) with no performance degradation - ideal for portable and space-constrained designs. |
| PowerPAD™ thermal package | MSOP-DGN package with exposed thermal pad achieves θJA = 58.4°C/W - enables >685 mW power dissipation at 85°C ambient. |
Applications
| ADC Driver for Precision Data Acquisition | Differential Transmitter in Signal Chain |
|---|---|
|
Use Scenario: Driving the differential input of a 14-bit, 100 MSPS pipeline ADC in a medical imaging front-end with 3.3 V supply constraint. IC Role / Device Role / Timing Role: Differential ADC driver providing matched, low-distortion 2 VPP output swing referenced to VOCM = AVDD/2. Use Value: Eliminates external level-shifting components and transformer; preserves SNR by rejecting board-level common-mode noise before digitization. |
Use Scenario: Converting single-ended sensor output (e.g., MEMS accelerometer) into balanced differential signal for transmission over noisy industrial backplane. IC Role / Device Role / Timing Role: Single-ended-to-differential converter with VOCM set to mid-supply, enabling robust noise-immune signal transport. Use Value: Doubles effective signal swing while halving even-order harmonics - improves EMI margin and reduces crosstalk susceptibility. |
| Antialiasing Filter Interface | High-Fidelity Audio Line Driver |
|
Use Scenario: Output stage of active antialiasing filter feeding 16-bit sigma-delta audio ADC in professional audio recorder. IC Role / Device Role / Timing Role: Final gain stage and buffer with controlled output impedance, configured for unity gain and VOCM = 1.65 V. Use Value: Maintains flat frequency response to 100 kHz and –75 dB THD ensures clean spectral content entering oversampled ADC. |
Use Scenario: Balanced line driver for studio-grade headphone amplifier output stage delivering ±1 V differential swing. IC Role / Device Role / Timing Role: Low-noise, low-distortion differential output buffer with VOCM tied to reference voltage for DC-coupled operation. Use Value: 5.4 nV/√Hz noise and 96 dB CMRR prevent ground loop hum and preserve stereo channel separation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fully differential amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| THS4131CDGNR | 150 MHz bandwidth, 51 V/µs slew rate, 1.3 nV/√Hz noise, wider 5–30 V supply range | Supports higher-frequency sampling (>50 MSPS) and lower-noise precision applications; requires ≥5 V supply | Select THS4131CDGNR when system supply allows ≥5 V and bandwidth >100 MHz is required; not drop-in due to supply and noise profile mismatch. |
| THS4561IRGET | 800 MHz bandwidth, 2200 V/µs slew rate, 2.2 nV/√Hz noise, integrated resistor network, 2.7–5.5 V supply | Targets RF/IF signal chains and GHz-range data converters; includes internal gain-setting resistors for simplified layout | Choose THS4561IRGET for >200 MSPS ADC interfaces or when board space constraints favor integrated feedback; incompatible with 3.3 V-only systems. |
Compared with THS4121CDGNR, THS4131CDGNR offers higher bandwidth and lower noise but demands higher supply voltage, while THS4561IRGET delivers RF-grade speed and integration at the cost of supply flexibility and increased quiescent current - making THS4121CDGNR optimal for cost-sensitive, 3.3 V, medium-bandwidth precision ADC driver roles.
Availability
THS4121CDGNR is available at Aetrix Electronics and suitable for precision data acquisition, industrial sensor signal conditioning, and medical instrumentation requiring stable component supply and long-term manufacturability.
Supply support for THS4121CDGNR 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 expertise in high-speed amplifier design and manufacturing.
The THS412x family was engineered specifically for high-fidelity, single-supply differential ADC driver applications - emphasizing distortion performance, noise efficiency, and VOCM-controlled output centering in compact thermally enhanced packages.
FAQ
What is the function of the VOCM pin on the THS4121CDGNR?
The VOCM pin on the THS4121CDGNR sets the DC common-mode voltage of both differential outputs. When driven to a specific voltage (e.g., 1.65 V for 3.3 V supply), it centers the VOUT+ and VOUT− swing around that level - enabling direct interfacing to ADCs with differential inputs referenced to AVDD/2. It must be bypassed with a 0.1 µF capacitor to ground for stability and noise suppression. This function is integral to the THS4121CDGNR's role as a precision ADC driver.
Does the THS4121CDGNR support power-down mode?
No, the THS4121CDGNR does not include a power-down pin or function. Unlike the THS4120CDGNR, which features a PD pin for reducing quiescent current to 120 µA, the THS4121CDGNR operates continuously with a typical IDD of 13.5 mA at 3.3 V. This reflects its design focus on consistent high-performance operation in always-on signal chains. System-level power management must be handled externally when using THS4121CDGNR.
What is the recommended PCB layout practice for the THS4121CDGNR thermal pad?
The THS4121CDGNR's MSOP PowerPAD™ package requires the exposed thermal pad to be soldered to a dedicated PCB copper pour connected to a thermal plane or ground layer. TI specifies θJA = 58.4°C/W only when the pad is properly thermally anchored. Avoid thermal relief patterns; use multiple vias (≥4, 0.3 mm diameter) connecting the pad to inner-layer copper. The pad is electrically isolated - no electrical connection to GND or any other net is needed or permitted. This thermal design is mandatory for THS4121CDGNR reliability at full load.
Can the THS4121CDGNR drive a 50 Ω transmission line directly?
The THS4121CDGNR should not drive a 50 Ω load directly due to potential instability and reduced phase margin. For capacitive or low-impedance loads >10 pF, TI recommends adding a 20–50 Ω series resistor at each output (VOUT+ and VOUT−) to isolate the amplifier from the load. In 50 Ω systems, a 50 Ω series resistor provides both isolation and source-end impedance matching. This requirement applies to all THS4121CDGNR configurations and is documented in the "Driving a Capacitive Load" section of its datasheet.
How does the THS4121CDGNR achieve improved harmonic distortion performance compared to standard op amps?
The THS4121CDGNR achieves –75 dB THD at 1 MHz through symmetrical fully differential topology: second-harmonic distortion components cancel at the balanced outputs, and matched internal transistor pairs minimize even-order nonlinearities. Its differential input stage rejects common-mode noise that would otherwise modulate distortion, while the VOCM-controlled output ensures precise centering - preventing clipping-related odd-order harmonics. These mechanisms are inherent to the THS4121CDGNR's architecture and validated across production units.
THS4121CDGNR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Amplifier Type:
- Differential
- Number of Circuits:
- 1
- Output Type:
- Differential
- Slew Rate:
- 55V/µs
- Gain Bandwidth Product:
- -
- -3db Bandwidth:
- 100 MHz
- Current - Input Bias:
- 1.2 pA
- Voltage - Input Offset:
- 3 mV
- Current - Supply:
- 11mA
- Current - Output / Channel:
- 100 mA
- Voltage - Supply Span (Min):
- 3 V
- Voltage - Supply Span (Max):
- 3.5 V
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-HVSSOP
THS4121CDGNR FAQ
1.How can I place an order for THS4121CDGNR through Aetrix?
Please submit a Request for Quotation (RFQ) for THS4121CDGNR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for THS4121CDGNR reliable?
The price and inventory of THS4121CDGNR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for THS4121CDGNR is usually 5 days.
3.What payment methods are accepted for THS4121CDGNR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for THS4121CDGNR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for THS4121CDGNR?
THS4121CDGNR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your THS4121CDGNR order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for THS4121CDGNR?
For technical support, including THS4121CDGNR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your THS4121CDGNR requirements.
6.How does Aetrix verify that THS4121CDGNR is sourced from the original manufacturer or authorized distributors?
All THS4121CDGNR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that THS4121CDGNR meets industry standards.
7.What is the process for return or replacement of THS4121CDGNR?
All THS4121CDGNR units undergo pre-shipment inspection (PSI). If there is an issue with THS4121CDGNR, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The THS4121CDGNR part is unused and in its original packaging.
Return procedure for THS4121CDGNR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
THS4121CDGNR Tags
-
LM358DT
STMicroelectronics
-
LM358DR
Texas Instruments
-
LM2904DR
Texas Instruments
-
LM358ADR
Texas Instruments
-
LM2904DGKR
Texas Instruments
-
LM324DR
Texas Instruments
-
MCP6006T-E/OT
Microchip Technology
-
MCP6006UT-E/OT
Microchip Technology
-
LM324PWR
Texas Instruments
-
LM2902PWR
Texas Instruments
-
LM2902DR
Texas Instruments
-
LM358P
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
