LMH6654MFX datasheet(12/17 Pages) NSC

12 / 17 page

Connection Diagrams

LMH6654 in SOIC

LMH6654 in SOT23-5

LMH6655 in SOIC and MSOP

20016521

Top View

20016520

Top View

20016519

Top View

Ordering Information

Package

Part Number

Package Marking

Transport Media

NSC Drawing

8-Pin SOIC

LMH6654MA

95 Units Rails

M08A

LMH6654MAX

2.5k Units Tape and Reel

LMH6655MA

95 Units Rails

LMH6655MAX

2.5k Units Tape and Reel

5-Pin SOT23-5

LMH6654MF

A66A

1k Units Tape and Reel

MF05A

LMH6654MFX

3K Units Tape and Reel

8-Pin MSOP

LMH6655MM

A67A

1k Units Tape and Reel

MUA08A

LMH6655MMX

3.5k Units Tape and Reel

Application Information

General Information

The LMH6654 single and LMH6655 dual high speed, voltage

feedback amplifiers are manufactured on National Semicon-

ductor’s new VIP10 (Vertically Integrated PNP) complemen-

tary bipolar process. These amplifiers can operate from

±2.5V to ±6V power supply. They offer low supply current,

wide bandwidth, very low voltage noise and large output

swing. Many of the typical performance plots found in the

datasheet can be reproduced if 50

Ω coax and 50Ω R

IN/ROUT

resistors are used.

Circuit Layout Consideration

With all high frequency devices, board layouts with stray

capacitance have a strong influence on the AC performance.

The LMH6654/55 are not exception and the inverting input

and output pins are particularly sensitive to the coupling of

parasitic capacitance to AC ground. Parasitic capacitances

on the inverting input and output nodes to ground could

cause frequency response peaking and possible circuit os-

cillation. Therefore, the power supply, ground traces and

ground plan should be placed away from the inverting input

and output pins. Also, it is very important to keep the para-

sitic capacitance across the feedback to an absolute mini-

mum.

The PCB should have a ground plane covering all unused

portion of the component side of the board to provide a low

impedance path. All trace lengths should be minimized to

reduce series inductance.

Supply bypassing is required for the amplifiers performance.

The bypass capacitors provide a low impedance return cur-

rent path at the supply pins. They also provide high fre-

quency filtering on the power supply traces. It is recom-

mended that a ceramic decoupling capacitor 0.1µF chip

should be placed with one end connected to the ground

plane and the other side as close as possible to the power

pins. An additional 10µF tantalum electrolytic capacitor

should be connected in parallel, to supply current for fast

large signal changes at the output.

Evaluation Boards

National provides the following evaluation boards as a guide

for high frequency layout and as an aid in device testing and

characterization.

Device

Package

Evalulation

Board PN

LMH6654MF

SOT23-5

CLC730068

LMH6654MA

8-Pin SOIC

CLC730027

LMH6655MA

8-Pin SOIC

CLC730036

LMH6655MM

8-Pin MSOP

CLC730123

20016541

FIGURE 1.

LMH6654MFX Datasheet(PDF) 12 Page - National Semiconductor (TI)

LMH6654MFX Datasheet(HTML) 12 Page - National Semiconductor (TI)

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