Overview
The LMH6518SQX/NOPB is a digitally controlled variable gain amplifier produced by Texas Instruments. This device is designed to offer high precision and flexibility in various high-frequency applications. It is particularly suited for driving Texas Instruments' gigasample per second (GSPS) analog-to-digital converters (ADCs) with adjustable full-scale ranges. The LMH6518 features a wide gain range, high bandwidth, and precise gain control, making it an ideal choice for applications requiring dynamic gain adjustment.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Gain Range | –1.16 dB to 38.8 dB | dB |
| Gain Step Size | 2 dB | dB |
| Combined Gain Resolution with GSPS ADCs | 8.5 mdB | mdB |
| –3dB Bandwidth (BW) | 900 MHz | MHz |
| Rise and Fall Time | < 500 ps | ps |
| Recovery Time | < 5 ns | ns |
| Propagation Delay Variation | 100 ps | ps |
| HD2 at 100 MHz | –50 dBc | dBc |
| HD3 at 100 MHz | –53 dBc | dBc |
| Input-referred Noise (Maximum Gain) | 0.98 nV/√Hz | nV/√Hz |
| Operating Temperature Range | –40°C to 85°C | °C |
| Package Type | 16-Pin WQFN (RGH) |
Key Features
- Digitally controlled variable gain with a 40 dB range in 2 dB steps
- High –3dB bandwidth of 900 MHz at all gains
- Precision gain control with gain accuracy of typically 0.1 dB at each setting
- Combined gain resolution of 8.5 mdB when used with GSPS ADCs
- Fast rise and fall times (< 500 ps) and recovery time (< 5 ns)
- Low propagation delay variation (100 ps)
- Overvoltage clamps for fast recovery
- Differential outputs with individual common-mode voltage control and selectable bandwidth limiting circuitry
- SPI-compatible serial bus for gain programming
Applications
- High-frequency single-ended input to differential conversion
- Precision gain control applications
- Medical applications
- RF/IF applications
- Driving GSPS ADCs with adjustable full-scale ranges
Q & A
- What is the gain range of the LMH6518? The gain range of the LMH6518 is from –1.16 dB to 38.8 dB.
- What is the gain step size of the LMH6518? The gain step size is 2 dB.
- What is the –3dB bandwidth of the LMH6518? The –3dB bandwidth is 900 MHz at all gains.
- How is the gain of the LMH6518 programmed? The gain is programmed through a SPI-compatible serial bus.
- What are the typical rise and fall times of the LMH6518? The rise and fall times are less than 500 ps.
- What is the recovery time of the LMH6518? The recovery time is less than 5 ns.
- Does the LMH6518 have overvoltage protection? Yes, it has overvoltage clamps for fast recovery.
- What type of outputs does the LMH6518 have? The LMH6518 has differential outputs with individual common-mode voltage control.
- What are some common applications of the LMH6518? Common applications include high-frequency single-ended input to differential conversion, precision gain control, medical applications, and RF/IF applications.
- What is the operating temperature range of the LMH6518? The operating temperature range is from –40°C to 85°C.
