LMH6518
- Gain Range: 40 dB
- Gain Step Size: 2 dB
- Combined Gain Resolution With Gsps ADCs:
8.5 mdB - Minimum Gain: −1.16 dB
- Maximum Gain: 38.8 dB
- −3 dB BW: 900 MHz
- Rise and Fall Time: <500 ps
- Recovery Time: <5 ns
- Propagation Delay Variation: 100 ps
- HD2 at 100 MHz: −50 dBc
- HD3 at 100 MHz: −53 dBc
- Input-Referred Noise (Maximum Gain): 0.98 nV/√Hz
- Overvoltage Clamps for Fast Recovery
- Power Consumption: Auxiliary Turned Off 1.1 W to 0.75 W
The LMH6518 device is a digitally controlled variable gain amplifier whose total gain is varied from −1.16 dB to 38.8 dB for a 40 dB range in 2-dB steps. The −3-dB bandwidth is 900 MHz at all gains. Gain accuracy at each setting is typically 0.1 dB. When used in conjunction with TI's Gsample/second (Gsps) ADC with adjustable full-scale (FS) range, the LMH6518 gain adjustment accommodates full scale input signals from 6.8 mVPP to 920 mVPP to get 700 mVPP nominal at the ADC input. The auxiliary output (+OUT AUX and −OUT AUX) follows the main output and is intended for use in oscilloscope trigger function circuitry but may have other uses in other applications.
The LMH6518 gain is programmed through a SPI-1 compatible serial bus. A signal path combined gain resolution of 8.5 mdB is achieved when the device's gain and the Gsps ADC’s FS input are both manipulated. Inputs and outputs are DC-coupled. The outputs are differential with individual common mode (CM) voltage control (for main and auxiliary outputs), and have a selectable bandwidth limiting circuitry (common to both main and auxiliary) of 20, 100, 200, 350, 650, 750 MHz or full bandwidth.
Technical documentation
| Type | Title | Date | ||
|---|---|---|---|---|
| * | Data sheet | LMH6518 900 MHz, Digitally Controlled, Variable Gain Amplifier datasheet (Rev. D) | PDF | HTML | 30 Sep 2016 |
| E-book | The Signal e-book: A compendium of blog posts on op amp design topics | 28 Mar 2017 | ||
| Application note | AN-1718 Differential Amplifier Applications Up to 400 MHz (Rev. B) | 01 May 2013 | ||
| Application note | AN-1719 Noise Figure Analysis Fully Differential Amplifier (Rev. A) | 01 May 2013 | ||
| EVM User's guide | AN-1906 LMH6518 Evaluation Board (Rev. B) | 01 May 2013 | ||
| Application note | Using High Speed Diff Amp to Drive ADCs (Rev. A) | 26 Apr 2013 | ||
| More literature | Featured High Speed Differential Amplifiers | 23 Oct 2012 | ||
| Application note | A Walk Along the Signal Path (High-Speed Signal Path) | 30 Mar 2005 |
Design & development
For additional terms or required resources, click any title below to view the detail page where available.
LMH6518DESIGN-CALC — LMH6518 Application Information FS Gain ECM Calculator
PSPICE-FOR-TI — PSpice® for TI design and simulation tool
TINA-TI — SPICE-based analog simulation program
| Package | Pins | Download |
|---|---|---|
| WQFN (RGH) | 16 | View options |
Ordering & quality
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