5.5 Thermal Information

THERMAL METRIC(1)

TPS737 Legacy silicon(2)

UNIT

DRB (VSON)

DCQ (SOT-223)

DRV (WSON)(3)

8 PINS

6 PINS

5 PINS

RθJA

Junction-to-ambient thermal resistance(4)

49.5

53.1

67.2

°C/W

RθJC(top)

Junction-to-case (top) thermal resistance(5)

58.9

35.2

87.6

°C/W

RθJB

Junction-to-board thermal resistance(6)

25.1

7.8

36.8

°C/W

ψJT

Junction-to-top characterization parameter(7)

1.7

2.9

1.8

°C/W

ψJB

Junction-to-board characterization parameter(8)

25.2

7.7

37.2

°C/W

RθJC(bot)

Junction-to-case (bottom) thermal resistance(9)

8.6

N/A

7.7

°C/W

(1)

For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application

note.

(2)

Thermal data for the DRB, DCQ, and DRV packages are derived by thermal simulations based on JEDEC-standard methodology

as specified in the JESD51 series. The following assumptions are used in the simulations:

(a) i. DRB: The exposed pad is connected to the PCB ground layer through a 2×2 thermal via array.

ii. DCQ: The exposed pad is connected to the PCB ground layer through a 3×2 thermal via array.

iii. DRV: The exposed pad is connected to the PCB ground layer through a 2×2 thermal via array. Due to size limitation of thermal pad,

0.8mm pitch array is used which is off the JEDEC standard.

(b) The top copper layer has a detailed copper trace pattern. The bottom copper layer is assumed to have a 20% thermal conductivity

of copper, representing a 20% copper coverage.

(c) These data are generated with only a single device at the center of a JEDEC high-K (2s2p) board with 3inch × 3inch copper area.

To understand the effects of the copper area on thermal performance, see the Power Dissipation and Estimating Junction Temperature

sections of this data sheet.

(3)

Power dissipation can limit operating range.

(4)

The junction-to-ambient thermal resistance under natural convection is obtained in a simulation on a JEDEC-standard, high-K board,

as specified in JESD51-7, in an environment described in JESD51-2a.

(5)

The junction-to-case (top) thermal resistance is obtained by simulating a cold plate test on the top of the package. No specific

JEDEC-standard test exists, but a close description can be found in the ANSI SEMI standard G30-88.

(6)

The junction-to-board thermal resistance is obtained by simulating in an environment with a ring cold plate fixture to control the

PCB temperature, as described in JESD51-8.

(7)

The junction-to-top characterization parameter, ψJT, estimates the junction temperature of a device in a real system and is

extracted from the simulation data to obtain RθJA using a procedure described in JESD51-2a (sections 6 and 7).

(8)

The junction-to-board characterization parameter, ψJB, estimates the junction temperature of a device in a real system and is

extracted from the simulation data to obtain RθJA using a procedure described in JESD51-2a (sections 6 and 7).

(9)

The junction-to-case (bottom) thermal resistance is obtained by simulating a cold plate test on the exposed (power) pad. No

specific JEDEC standard test exists, but a close description can be found in the ANSI SEMI standard G30-88.

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TPS737

SBVS067W – JANUARY 2006 – REVISED AUGUST 2025

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