Datasheet HMC976LP3E (Analog Devices) - 10

HMC976LP3E
v02.1112
400mA LOW NOISE, HIGH PSRR LINEAR VOLTAGE REGULATOR
Thermal dissipation should be taken into account at all times especial y with large dropout voltages VDD-VR, i.e. if 1.8V output is required from 5.5V input voltage, then the output current must be restricted to <210mA , or VDD restricted to <3.75V for a 400mA load. The exact maximum operating temperature before the thermal protection circuit activates is largely dependent on the customer PCB design. Below is an example for maximum ambient temperature calculation for the standard HMC976LP3E evaluation PCB with no heat sink and no air flow (fans). Customers should perform this calculation for their PCB layout and operating conditions. VIN=5.5V, Vout=5.0V, Iout=400mA Vdropout=VIN-VOUT=0.5V Dissipated power on regulator Pd=0.5Vx0.4A=0.2W = θja 51.5°C/W Junction temperature increase using standard HMC976 board: DTj=Pd x θ = ja 10.3°C. Thermal shutdown junction temperature of regulator (absolute min) Tsdwn=+115°C. Maximum corresponding ambient temperature Ta_max = Tsdwn - DTj = +104.7°C The plots below show how the PCB ground copper area affects the HMC976LP3E junction temperature for different HMC976LP3E power dissipation conditions. The following cases are included in the plots: 1. 100 mm2 Copper Area 2. 1000 mm2 Copper Area 3. 2580 mm2 Copper Area HMC976LP3E Evaluation PCB No Heat Sink (HS) 4. 2580 mm2 Copper Area HMC976LP3E Evaluation PCB with Heat Sink (HS) 5. JEDEC Board as per JESD51-3 T The typical corresponding i θja s shown in Table 8: M
Table 8. Typical for specified PCB Copper Sizes
θja G - S Copper size (mm2) ( θja °C/W) IN 100 173.5 N 1000 57.3 2580 no HS 51.5 IO 2580 with HS 44 IT D
Figure 14. HMC976LP3E JUNCTION TEMPERATURE Figure 15. HMC976LP3E JUNCTION TEMPERATURE
N
°C vs. TOTAL POWER DISSIPATION 25°C AMBIENT °C vs. TOTAL POWER DISSIPATION 50°C AMBIENT
O 150 150 115°C WORST CASE 115°C WORST CASE THERMAL SHUTDOWN THERMAL SHUTDOWN 125 (°C) 125 (°C) R C Tj Tjmax Tj Tjmax E 100mm2 no HS 100mm2 no HS 1000mm2 no HS 100 100 2580mm2 no HS W 1000mm2 no HS 2580mm2 with HS O 75 TEMPERATURE 2580mm2 no HS 75 TEMPERATURE P 2580mm2 with HS 50 50 JEDEC no HS JUNCTION JUNCTION JEDEC no HS 25 25 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 POWER DISSIPATION (W) POWER DISSIPATION (W) InfoFro ma r p tion rfiucre nis, d he e d lbiv y e An raly a og n Ded t viceo p s is la be clie o eved rtd o e b re sa: H ccur iattti e te M and re ilicarbloew . a Ho ve C wever, onro For price, delivery, and to place orders: Analog Devices, Inc., responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other poration, 2 Elizabeth Drive, Chelmsford, MA 01824 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106 978-250-3343 tel • 978-250-3373 fax • O rights of third parties that may result from its use. Specifications subject to change without notice. No rd P e h r O one n : 7-lin 81- e a 329-t w 47 w 0 w.h 0 • O it rd teite r o .nc li o n m license is granted by implication or otherwise under any patent or patent rights of Analog Devices. e at www.analog.com 10 Application S Trademarks and registered trademarks are the property of their respective owners. upport: apps@ A h p i p tliti c te ati .ocom n Support: Phone: 1-800-ANALOG-D