Datasheet

V
+
10 µF
0.1 µF
0.1 µF
10 µF
V
-
+
+
LMH6654, LMH6655
SNOS956D –JUNE 2001–REVISED MARCH 2013 www.ti.com
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 current path at the supply pins. They also provide high frequency filtering on the power supply traces. It is
recommended that a ceramic decoupling capacitor 0.1 µF 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 10 µF tantalum electrolytic
capacitor should be connected in parallel, to supply current for fast large signal changes at the output.
Figure 43. Supply Bypass Capacitors
EVALUATION BOARDS
TI 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 5-Pin SOT-23 LMH730216
LMH6654MA 8-Pin SOIC LMH730227
LMH6655MA 8-Pin SOIC LMH730036
LMH6655MM 8-Pin VSSOP (DGK) LMH730123
Components Needed to Evaluate the LMH6654 on the LMH730227 Evaluation Board:
• R
f
R
g
use the datasheet to select values.
• R
IN
, R
OUT
typically 50Ω (Refer to the Basic Operation section of the evaluation board datasheet for details)
• R
f
is an optional resistor for inverting again configurations (select R
f
to yield desired input impedance = R
g
||R
f
)
• C
1
, C
2
use 0.1 µF ceramic capacitors
• C
3
, C
4
use 10 µF tantalum capacitors
Components not used:
1. C
5
, C
6
, C
7
, C
8
2. R1 thru R8
The evaluation boards are designed to accommodate dual supplies. The board can be modified to provide single
operation. For best performance;
1) do not connect the unused supply.
2) ground the unused supply pin.
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Product Folder Links: LMH6654 LMH6655