IN+

IN-

R

R

V-

V+

V+

V+

V-

LMH6642, LMH6643, LMH6644

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SNOS966Q – MAY 2001 – REVISED SEPTEMBER 2014

8 Detailed Description

8.1 Overview

The LMH664X family is based on proprietary VIP10 dielectrically isolated bipolar process. This device family

architecture features the following:

•

low bias current.

•

A class A-B “turn-around” stage with improved noise, offset, and reduced power dissipation compared to

similar speed devices (patent pending).

•

Common Emitter push-push output stage capable of 75 mA output current (at 0.5 V from the supply rails)

while consuming only 2.7 mA of total supply current per channel. This architecture allows output to reach

within mV of either supply rail.

•

Consistent performance over the entire operating supply voltage range with little variation for the most

•

Significant power saving (

∼40%) compared to competitive devices on the market with similar performance.

8.2 Functional Block Diagram

Figure 54. Input Equivalent Circuit

8.3 Feature Description

The LMH664X family is a drop-in replacement for the AD805X family of high speed Op Amps in most

applications. In addition, the LMH664X will typically save about 40% on power dissipation, due to lower supply

current, when compared to competition. All AD805X family’s specified parameters are included in the list of

LMH664X ensured specifications in order to ensure equal or better level of performance. However, as in most

high performance parts, due to subtleties of applications, it is strongly recommended that the performance of the

part to be evaluated is tested under actual operating conditions to ensure full compliance to all specifications.

8.4 Device Functional Modes

applications in low voltage/low power applications. Even with 3-V supplies, the

115 MHz with a tested limit of 80 MHz. Production testing guarantees that process variations will not compromise

speed. High frequency response is exceptionally stable, confining the typical

−3dB BW over the industrial

temperature range to ±2.5%.

As seen in Typical Performance Characteristics, the LMH664X output current capability (

∼75 mA) is enhanced

compared to AD805X. This enhancement increases the output load range, adding to the LMH664X’s versatility.

Since LMH664X is capable of high output current, device junction temperature should not to exceed the Absolute

Maximum Ratings.

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