Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsLinear IC - Op-amp, differential amplifier Differential WQFN 24 (4x4)

LMH6881

SNOSC72E –JUNE 2012–REVISED MARCH 2013

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THERMAL CONSIDERATION

The LMH6881 is packaged in a thermally enhanced package. The exposed pad on the bottom of the package is

the primary means of removing heat from the package. It is recommended, but not necessary, that the exposed

pad be connected to the supply ground plane. In any case, the thermal dissipation of the device is largely

dependent on the attachment of the exposed pad to the system PCB. The exposed pad should be attached to as

much copper on the PCB as possible, preferably external layers of copper. It is also very important to maintain

good high-speed layout practices when designing a system board. Please refer to the LMH6881 evaluation board

for suggested layout techniques. The LMH6881EVAL evaluation board was designed for both signal integrity and

thermal dissipation. The LMH6881EVAL evaluation board uses higher performance dielectric (Rogers) on the top

layer for high frequency signal fidelity.

CONCLUSION

The LMH6881 is a fully differential amplifier optimized for signal-path applications up to 1000 MHz. The

LMH6881 has a 100-Ω input impedance and a low (less than 0.5 Ω) impedance output. The gain is digitally

controlled over a 20-dB range from 26 dB to 6 dB. The LMH6881 is designed to replace fixed-gain differential

amplifiers with a single, flexible-gain device. It has been designed to provide good noise figure and OIP3 over the

entire gain range. This design feature is highlighted by the DRF of merit. Traditional variable gain amplifiers

generally have the best OIP3 and NF performance at maximum gain only.

Table 7. COMPATIBLE HIGH SPEED ANALOG-TO-DIGITAL CONVERTERS

Product Number Max Sampling Rate (MSPS) Resolution Channels

ADC12D1800RF 1800 12 DUAL

ADC12D1600RF 1600 12 DUAL

12D1000 RF 1000 12 DUAL

ADC12D800RF 800 12 DUAL

ADS5400 1000 12 SINGLE

ADC12C105 105 12 SINGLE

ADC10D1500 1500 10 DUAL

ADC12C170 170 12 SINGLE

ADC12V170 170 12 SINGLE

ADC14C105 105 14 SINGLE

ADC14DS105 105 14 DUAL

ADC14155 155 14 SINGLE

ADC14V155 155 14 SINGLE

ADC16V130 130 16 SINGLE

ADC16DV160 160 16 DUAL

ADC08D500 500 8 DUAL

ADC08500 500 8 SINGLE

ADC08D1000 1000 8 DUAL

ADC081000 1000 8 SINGLE

ADC08D1500 1500 8 DUAL

ADC081500 1500 8 SINGLE

ADC08(B)3000 3000 8 SINGLE

ADC08100 100 8 SINGLE

ADCS9888 170 8 SINGLE

ADC08(B)200 200 8 SINGLE

ADC11C125 125 11 SINGLE

ADC11C170 170 11 SINGLE

Product Folder Links: LMH6881