General Description

The LMH6505 is a wideband DC coupled voltage controlled gain stage followed by a high speed current feedback operational amplifier which can directly drive a low impedance load. The gain adjustment range is 80 dB for up to 10 MHz which is accomplished by varying the gain control input voltage, VG.

Maximum gain is set by external components, and the gain can be reduced all the way to cutoff. Power consumption is 110 mW with a speed of 150 MHz and a gain control bandwidth (BW) of 100 MHz. Output referred DC offset voltage is less than 55 mV over the entire gain control voltage range. Device-to-device gain matching is within ±0.5 dB at maximum gain. Furthermore, gain is tested and guaranteed over a wide range. The output current feedback op amp allows high frequency large signals (Slew Rate = 1500 V/μs) and can also drive a heavy load current (60 mA) guaranteed. Near ideal input characteristics (i.e. low input bias current, low offset, low pin 3 resistance) enable the device to be easily configured as an inverting amplifier as well.

Features

VS = ±5V, TA = 25°C, RF = 1 kΩ, RG = 100Ω, RL = 100Ω,

AV = AVMAX = 9.4 V/V, Typical values unless specified.

■ −3 dB BW 150 MHz

■ Gain control BW 100 MHz

■ Adjustment range (<10 MHz) 80 dB

■ Gain matching (limit) ±0.50 dB

■ Supply voltage range 7V to 12V

■ Slew rate (inverting) 1500 V/μs

■ Supply current (no load) 11 mA

■ Linear output current ±60 mA

■ Output voltage swing ±2.4V

■ Input noise voltage 4.4 nV/√Hz

■ Input noise current 2.6 pA/√Hz

■ THD (20 MHz, RL = 100Ω, VO = 2 VPP) −45 dBc

Applications

■ Variable attenuator

■ AGC

■ Voltage controlled filter

■ Video imaging processing