LMH6572_05 Datasheet, PDF (11/12 Pages) National Semiconductor (TI) – Triple 2:1 High Speed Video Multiplexer

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consumes 23 mA of quiescent current, which cannot be
neglected when considering the total package power dissi-
pation limit. To ensure maximum output drive and highest
performance, thermal shutdown is not provided. Therefore, it
is of utmost importance to make sure that the T_JMAX is never
exceeded due to the overall power dissipation.
Follow these steps to determine the Maximum power dissi-
pation for the LMH6572:
1. Calculate the quiescent (no-load) power: P_AMP = I_CC*
(V_S), where V_S = V⁺ - V^−.
2. Calculate the RMS power dissipated in the output stage:
P_D (rms) = rms ((V_S - V_OUT) * I_OUT), where V_OUT and
I_OUT are the voltage across and the current through the
external load and V_S is the total supply voltage.
3. Calculate the total RMS power: P_T = P_AMP + P_D.
The maximum power that the LMH6572 package can dissi-
pate at a given temperature can be derived with the following
equation:
P_MAX = (150˚ – T_AMB)/ θ_JA, where T_AMB = Ambient Tempera-
ture (˚C) and θ_JA = Thermal Resistance from junction to
ambient for a given package (˚C/W). For the SSOP package
θ_JA is 125˚C/W.
ESD PROTECTION
The LMH6572 is protected against electrostatic discharge
(ESD) on all pins. The LMH6572 will survive 2000V Human
Body model and 200V Machine model events. Under normal
operation the ESD diodes have no effect on circuit perfor-
mance. There are occasions, however, when the ESD di-
odes will be evident. If the LMH6572 is driven by a large
signal while the device is powered down the ESD diodes will
conduct. The current that flows through the ESD diodes will
either exit the chip through the supply pins or will flow
through the device, hence it is possible to power up a chip
with a large signal applied to the input pins. Shorting the
power pins to each other will prevent the chip from being
powered up through the input.
EVALUATION BOARDS
National Semiconductor provides the following evaluation
boards as a guide for high frequency layout and as an aid in
device testing and characterization. Many of the datasheet
plots were measured with these boards.
Device
LMH6572
Package
TSSOP
Evaluation Board
Part Number
LMH730151
An evaluation board can be shipped when a device sample
request is placed with National Semiconductor.
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