THS4031IDGNR - 100MHz Low-Noise VFB Amplifier | Texas Instruments
料号： THS4031IDGNR ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $5.26 | $5.26 |
| 10 | $4.72 | $47.20 |
| 100 | $3.87 | $387.00 |
| 500 | $3.29 | $1,645.00 |
| 1,000 | $2.78 | $2,780.00 |
THS4031IDGNR 概述
A voltage-feedback amplifier (VFA) is an operational amplifier in which the feedback network controls the differential input voltage, giving it a constant gain-bandwidth product. Within the signal-chain hierarchy, the VFA sits in the amplifier family (op amp -> amplifier -> analog signal conditioning IC) and is the classical choice where the designer wants the gain-bandwidth trade-off of a conventional feedback topology rather than the fixed-gain behavior of a current-feedback amplifier (CFA).
The defining feature of the THS4031 is its 1.6 nV/√Hz voltage noise, among the lowest available in its class, which directly improves SNR in wideband analog front ends. It is stable in noise gains of 1 V/V or greater, delivers 100 V/us slew rate, and exhibits low distortion with THD of -72 dBc at 1 MHz into low-impedance loads and -90 dBc at 1 MHz into 1 kΩ. The typical input offset voltage is only 0.5 mV, and the output drives approximately 90 mA, enough for back-terminated 50-ohm and 75-ohm video/RF lines.
Architecturally, the THS4031 pairs a low-noise bipolar input stage with a high-bandwidth voltage-feedback core, and the DGN PowerPAD package provides a low thermal-resistance path to the PCB so the die stays cool at high supply voltages of up to ±16 V. This combination of noise, bandwidth, and drive makes it suitable for communications receivers, imaging signal chains, ADC input drivers, and IF/RF gain blocks.
Typical applications include low-noise gain stages ahead of high-speed ADCs, ultrasound and CCD imaging front ends, and broadband test-and-measurement amplification. The supply range of ±4.5 V to ±16 V supports both ±5 V and ±15 V analog rails.
Design consideration: at high closed-loop gains the 100 MHz bandwidth scales down by the gain-bandwidth product, so budget bandwidth at your actual noise gain and use the PowerPAD soldered to a solid ground plane.
This page adds distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
直接替换替代料： THS4031IDGNR ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： THS4031IDGNR （相同外形与封装尺寸） ——差异在于 Amplifier Type, Bandwidth, Input Voltage Noise, Package, Stability.
快速对比工具——选择替代料号进行并排对比：
THS4031IDGNRG4
✅ 直接替换📋 参考替代料（不在目录中）
THS4031IDGN
✅ 直接替换📋 参考替代料（不在目录中）
THS4031CDGNR
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$1.62 / 个
查看数据手册 →THS4031CDGNG4
✅ 直接替换📋 参考替代料（不在目录中）
THS4032IDGNR
✅ 直接替换📋 参考替代料（不在目录中）
THS4021CDGNR
✅ 直接替换📋 参考替代料（不在目录中）
THS4031IDGNR 最大额定值与电气特性
| Amplifier Type | Voltage Feedback Amplifier |
| Number of Channels | 1 |
| Bandwidth | 100 MHz (G = -1) |
| Slew Rate | 100 V/us |
| Input Voltage Noise | 1.6 nV/sqrt(Hz) |
| Input Offset Voltage | 0.5 mV (typ) |
| THD at 1 MHz (low-Z load) | -72 dBc |
| THD at 1 MHz (1 kOhm load) | -90 dBc |
| Output Current | 90 mA |
| Supply Voltage Range | +-4.5 V to +-16 V |
| Stability | Stable in gains of 1 V/V or greater |
| 工作温度范围 | -40C to +85C (I grade) |
| 封装 | 8-HVSSOP (DGN) with PowerPAD |
| 引脚数 | 8 |
| 安装类型 | Surface Mount |
| RoHS 状态 | RoHS3 Compliant |
THS4031IDGNR 引脚配置
| 引脚 1 | OUT — Amplifier output |
| 引脚 2 | -IN — Inverting input |
| 引脚 3 | +IN — Non-inverting input |
| 引脚 4 | V- — Negative supply |
| 引脚 5 | NC — Not connected (per datasheet) |
| 引脚 6 | NC — Not connected (per datasheet) |
| 引脚 7 | V+ — Positive supply |
| 引脚 8 | NC — Not connected (per datasheet); PowerPAD on underside soldered to ground plane for thermal dissipation |
典型应用
THS4031IDGNR 适用于 6 应用s: High-Speed ADC Input Driver, Communications Receiver IF Gain Blocks, Ultrasound and Imaging Front Ends, Test and Measurement Instrumentation, Video and Wideband Signal Distribution, Active Filter and Signal Conditioning Stages.
High-Speed ADC Input Driver
The THS4031IDGNR excels as an ADC driver because its 1.6 nV/√Hz input noise adds negligible noise to the ADC's own aperture and thermal noise budget, preserving effective-number-of-bits (ENOB) in 12- to 16-bit pipelines sampling at tens of MHz. Placed directly in front of the ADC with an RC filter between amplifier output and sampling capacitor, the 100 MHz bandwidth settles quickly between conversion steps, while the 90 mA output current easily charges typical ADC input capacitance through the filter resistor. The voltage-feedback topology allows classic resistor-ratio gain setting, so the engineer can match the signal span to the ADC full-scale range precisely. Using the DGN PowerPAD soldered to the ground plane keeps junction temperature low during continuous high-frequency drive.
推荐
Communications Receiver IF Gain Blocks
In communications receivers, the IF chain demands amplifiers whose noise floor does not degrade the cascaded noise figure. The THS4031IDGNR's 1.6 nV/√Hz voltage noise, when referred through a typical 50- to 200-ohm IF impedance, contributes minimally compared with source thermal noise, making it well suited to IF gain stages between mixers and ADCs. The 100 MHz bandwidth covers wideband IF bandwidths well beyond typical 10-50 MHz IF channels, and the -72 dBc distortion at 1 MHz keeps intermodulation products below the dynamic range targets of multi-carrier receivers. Its operation from ±5 V or ±15 V rails lets designers reuse the same gain-block design across battery-powered radios and rack-mounted test receivers.
推荐
Ultrasound and Imaging Front Ends
Medical ultrasound and CCD/CMOS imaging chains are exactly the applications TI cites for the THS403x family. Piezo transducer and photodiode signals are small and bandwidth-rich, so the front-end amplifier's 1.6 nV/√Hz noise directly determines the smallest detectable echo or pixel charge. The THS4031IDGNR's 100 MHz bandwidth preserves the fast transducer ring-down edges needed for axial resolution, and its low 0.5 mV typical offset keeps DC levels stable across long receive windows. Time-gain-compensation (TGC) stages implemented with THS4031 gain blocks maintain consistent bandwidth as gain varies, because the voltage-feedback architecture keeps the gain-bandwidth product constant. The PowerPAD package handles the duty-cycle heat of pulsed transmit/receive operation.
推荐
Test and Measurement Instrumentation
Oscilloscope, spectrum analyzer, and arbitrary-waveform front ends benefit from the THS4031IDGNR's combination of 100 MHz bandwidth, 100 V/us slew rate, and -90 dBc distortion into 1 kΩ loads at 1 MHz. Input attenuator/preamp stages built with the THS4031 maintain flat gain across the band, and the ±4.5 V to ±16 V supply range allows designs referenced to traditional ±15 V instrument rails without redesign. The 0.5 mV typical input offset minimizes baseline drift that would otherwise require periodic auto-zero calibration. Because the device is stable at unity gain, it can also serve as the final low-impedance buffer driving 50-ohm back-terminated outputs, using its 90 mA output current capability.
推荐
Video and Wideband Signal Distribution
Composite and component video, plus general 75-ohm distribution systems, require amplifiers with low differential gain and phase error and enough current to drive back-terminated lines. The THS4031IDGNR's -72 dBc distortion at 1 MHz into low-impedance loads translates to clean video harmonics, and its 90 mA output supports 75-ohm back-terminated drive at standard video levels. The 100 MHz bandwidth far exceeds the 8-40 MHz requirements of high-definition video formats, ensuring minimal pulse ringing and overshoot. Designers typically configure the THS4031 with a gain of 2 V/V to compensate the 6 dB back-termination loss, well within its unity-gain-stable operating envelope, while the DGN PowerPAD thermal path keeps die temperature controlled during continuous broadcast duty.
推荐
Active Filter and Signal Conditioning Stages
Wideband active filters (multiple-feedback and Sallen-Key topologies) require amplifiers whose open-loop bandwidth is at least an order of magnitude above the filter corner to keep the actual response close to the transfer-function prediction. With 100 MHz bandwidth, the THS4031IDGNR supports filters with corners into the tens of MHz while holding Q accuracy, and the low 1.6 nV/√Hz noise keeps the filter's output noise floor low for follow-on gain stages. The stable-at-gain-1-or-greater specification suits Sallen-Key unity-gain sections directly. Resistor values should be kept moderate (hundreds of ohms to a few kilohms) so stray capacitance does not move pole locations, and the ±5 V supply option simplifies integration into mixed-signal boards.
推荐
推荐产品汇总
工程参考数据： THS4031IDGNR ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | THS4031IDGNRG4 | THS4031IDGN | THS4031CDGNR | THS4032IDGNR | THS4021CDGNR |
|---|---|---|---|---|---|---|
| Package | 8-HVSSOP (DGN) PowerPAD | 8-HVSSOP (DGN) - same | 8-HVSSOP (DGN) - same | 8-HVSSOP (DGN) - same | 8-HVSSOP (DGN) - same | 8-HVSSOP (DGN) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Operating Temperature | -40C to +85C (I grade) | -40C to +85C | -40C to +85C | 0C to +70C (C grade) | -40C to +85C | 0C to +70C (C grade) |
| Channels | 1 | 1 | 1 | 1 | 2 (dual, different pin functions) | 1 |
关键差异点
- Ultra-low 1.6 nV/√Hz voltage noise in a voltage-feedback topology （对比 THS4021CDGNR)
- Single-channel pin map preserved vs dual version （对比 THS4032IDGNR)
- Industrial temperature range at commercial price （对比 THS4031CDGNR)
- Unity-gain-stable voltage feedback vs current-feedback parts （对比 THS4021CDGNR)
设计说明
The 8-HVSSOP (DGN) PowerPAD package relies on the exposed pad under the die for heat removal. Solder the PowerPAD directly to a solid ground plane with an array of thermal vias (typically 5x5 via pattern recommended in TI PowerPAD application notes). Estimated: at ±15 V supplies with a 10 mA quiescent-class load plus 50 mA output current, dissipation can approach 1.5-2 W, and an unsoldered PowerPAD raises junction temperature dramatically versus the datasheet theta-JA figure, which assumes a properly soldered pad. Verify junction temperature with your actual supply, load, and ambient conditions.
Place supply decoupling capacitors (0.1 uF ceramic in parallel with 2.2-6.8 uF per rail) within 2-3 mm of the V+ and V- pins, connected to a low-impedance ground return. At 100 MHz bandwidth, even a few nanohenries of trace inductance degrades PSRR and can permit high-frequency oscillation. Keep the feedback path short, remove ground plane under the inverting input node to reduce stray capacitance (which lowers phase margin in VFAs), and use a ground plane cutout only where the sensitive nodes run.
The 100 MHz bandwidth is specified at a gain of -1 V/V; at a noise gain of 10, closed-loop bandwidth drops to roughly one-tenth (gain-bandwidth product behavior). Budget bandwidth at your actual noise gain, not at unity gain. Also, the part is stable only for noise gains of 1 V/V or greater - do not configure noise gains below unity. Finally, when substituting the dual THS4032IDGNR on the same footprint, remember the pin functions differ (two channels share the package), so a single-channel layout must be re-verified.
For driving 50-ohm or 75-ohm cables, use a series back-termination resistor at the amplifier output and accept the 6 dB loss, setting closed-loop gain to 2 V/V to compensate. The 90 mA output current supports this at moderate swings from ±5 V or higher rails. Source-terminate rather than double-terminate directly at the amplifier output when full swing is needed, and check the datasheet distortion curves at your specific load and frequency to confirm harmonic levels meet system requirements.
合规信息
Distributor records list ROHS3 compliant and lead-free status for THS4031IDGNR. REACH and halogen-free declarations not found in provided data; consult TI environmental pages.
