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ManualsBrandsST ManualsSensor ModuleST VL53L8CX Ranging Sensor Module

Table Of Contents

Introduction

When used in continuous mode, the VL53L8CX module typically consumes 215 mW of power. Consequently, it requires careful

thermal management to ensure optimum device performance and to avoid overheating.

Table 1. Main thermal parameters

Parameter Symbol Min. Typ. Max. Unit

Power consumption P —

215

(1)

320 mW

Junction temperature

(2)

— — 110 °C

Die thermal resistance

die

— — 43 °C/W

Operating temperature range T -30 25 85 °C

1. AVDD = 2.8 V and IOVDD = 1.8 V of typical current consumption.

2. To prevent thermal shutdown, the junction temperature must be kept below 110 °C.

Figure 1. VL53L8CX ranging sensor module

PCB thermal guidelines for the VL53L8CX robust, low-power, 8x8 multizone

Time-of-Flight sensor with enhanced ranging performance

AN5897

Application note

AN5897 - Rev 1 - January 2023

For further information contact your local STMicroelectronics sales office.

www.st.com

Summary of content (6 pages)

PAGE 1
AN5897 Application note PCB thermal guidelines for the VL53L8CX robust, low-power, 8x8 multizone Time-of-Flight sensor with enhanced ranging performance Introduction When used in continuous mode, the VL53L8CX module typically consumes 215 mW of power. Consequently, it requires careful thermal management to ensure optimum device performance and to avoid overheating. Table 1. Main thermal parameters Parameter Symbol Min. Typ. Max.
PAGE 2
AN5897 Thermal design basics 1 Thermal design basics The symbol θ is generally used to denote thermal resistance which is a measure of a temperature difference by which an object or material resists a heat flow. For example, when transferring from a hot object (such as silicon junction) to a cool one (such as module backside temperature or ambient air).
PAGE 3
AN5897 Thermal resistance of PCB or flex 2 Thermal resistance of PCB or flex The maximum permitted junction temperature of the VL53L8CX is 110°C. The maximum permitted PCB or flex thermal resistance is calculated as shown below. This calculation is for a power dissipation of 0.320 W, and device operation at 85°C (worst case scenario of the maximum specified ambient temperature). θpcb = T J − TA ÷ P − θdie θpcb = 110 − 85 ÷ 0.
PAGE 4
AN5897 Layout and thermal guidelines 3 Layout and thermal guidelines Use the following guidelines when designing the module PCB or flex: • • • • • • Maximize the copper cover on the PCB to increase the thermal conductivity of the board. Use the module, thermal pad B4 shown in Figure 2. VL53L8CX pinout and thermal pad. Add a single large rectangle of solder paste. It should be the same size as the thermal pad (eight rectangles) as per Figure 3. Recommendation for the thermal pad and via on the PCB.
PAGE 5
AN5897 Revision history Table 2.
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AN5897 IMPORTANT NOTICE – READ CAREFULLY STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, enhancements, modifications, and improvements to ST products and/or to this document at any time without notice. Purchasers should obtain the latest relevant information on ST products before placing orders. ST products are sold pursuant to ST’s terms and conditions of sale in place at the time of order acknowledgment.