DLPA2000 datasheet(56/63 Pages) TI

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10.1.9 Routing Vias

• The number of vias on DMD_HS signals must be minimized and ideally not exceed two.

• Any and all vias on DMD_HS signals must be located as close to the controller as possible.

• The number of vias on the DMD_LS_CLK and DMD_LS_WDATA signals must be minimized and ideally not

exceed two.

• Any and all vias on the DMD_LS_CLK and DMD_LS_WDATA signals must be located as close to the

controller as possible.

10.1.10 Thermal Considerations

The underlying thermal limitation for the DLPC34xx controller is that the maximum operating junction

temperature (TJ) not be exceeded (this is defined in the Recommended Operating Conditions section).

Some factors that influence TJ are as follows:

• operating ambient temperature

• airflow

• PCB design (including the component layout density and the amount of copper used)

• power dissipation of the DLPC34xx controller

• power dissipation of surrounding components

The controller package is designed to primarily extract heat through the power and ground planes of the PCB.

Thus, copper content and airflow over the PCB are important factors.

The recommends maximum operating ambient temperature (TA) is provided primarily as a design target and is

based on maximum DLPC34xx controller power dissipation and RθJA at 0 m/s of forced airflow, where RθJA is the

thermal resistance of the package as measured using a JEDEC defined standard test PCB with two, 1-oz power

planes. This JEDEC test PCB is not necessarily representative of the DLPC34xx controller PCB, so the reported

thermal resistance may not be accurate in the actual product application. Although the actual thermal resistance

may be different, it is the best information available during the design phase to estimate thermal performance.

TI highly recommended that thermal performance be measured and validated after the PCB is designed and the

application is built.

To evaluate the thermal performance, measure the top center case temperature under the worse case product

scenario (maximum power dissipation, maximum voltage, maximum ambient temperature), and validate the

controller does not exceed the maximum recommended case temperature (TC). This specification is based on

the measured φJT for the DLPC34xx controller package and provides a relatively accurate correlation to junction

temperature.

Take care when measuring this case temperature to prevent accidental cooling of the package surface. TI

recommends a small (approximately 40 gauge) thermocouple. Place the bead and thermocouple wire so that

they contact the top of the package. Cover the bead and thermocouple wire with a minimal amount of thermally

conductive epoxy. Route the wires closely along the package and the board surface to avoid cooling the bead

through the wires.

DLPC3420

DLPS232 – OCTOBER 2021

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DLPA2000 Datenblatt(PDF) 56 Page - Texas Instruments