HDP01-0512N ® Application Specific Discretes A.S.D.TM HARD DISK DRIVE POWER SUPPLY PROTECTION APPLICATIONS PROTECTION FOR THE +5V AND +12V POWER LINES OF: - Hard disk drives - Floppy disk drives - CD-ROMs, CD-R, CD-RW - DVDs PL5 GND PL5 FEATURES PL12 PROTECTION OF BOTH 5V AND 12V SUPPLY RAILS. MAXIMUM CURRENT ON THE 5V LINE 3A DURING 1s. MONOLITHIC INTEGRATION IN PLANAR TECHNOLOGY. SOT223 DESCRIPTION This device is dedicated to the protection of the +5V power supply line against transient overvoltages due to surge of power rails up to the activation of the serial thermal protection element. It is also dedicated to the protection of the +12V rail against transient overvoltages. BENEFITS COMPONENT COUNT REDUCTION PCB SURFACE REDUCTION SIMPLIFIED SYSTEM PROTECTION DESIGN BASIC APPLICATION DIAGRAM Unprotected 5V Protected 5V Unprotected 12V PL12 PL5 Protected 12V PL12 PL5 OVERVOLTAGE CLAMPING OVERVOLTAGE DETECTION HDP01-0512N Gnd note: The element in series with the 5V line is a resettable device, like Raychem Polyswitch MiniSMD075. TM : ASD is trademark of STMicroelectronics. April 1999 - Ed: 6A 1/6 HDP01-0512N ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit 1 s 0 to + 75 °C 125 - 55 to + 150 °C °C 260 °C Value Unit Junction to tab 30 °C/W Junction to ambient (note 2) 60 °C/W ton Conduction time with I-PL5 = 3A DC (note1) Top Operating temperature range Tj Tstg Maximum junction temperature Storage temperature range Lead solder temperature (10s duration) TL note 1 : I-PL5 is the current going through the 5V line (PL5) THERMAL RESISTANCE Symbol Parameter Rth (j-t) Rth (j-a) 2 note 2 : With 5cm copper (e=35µm) surface under tab. ELECTRICAL CHARACTERISTICS (Tamb=25°C) I I +5V PROTECTION +12V PROTECTION ION IA-PL5 Slope = 1 / Rd VA-PL5 IRM-PL5 IRM-PL12 VON-PL5 VRM-PL5 VNA-PL5 VRM-PL12 VBR-PL12 ELECTRICAL CHARACTERISTICS (Tamb = 25°C) PROTECTION OF 5 V LINE (PL5) Symbol Parameter VNA-PL5 Non activation voltage between PL5 and Gnd at IRM=100µA VA-PL5 IRM-PL5 Activation voltage between PL5 and Gnd Value Min. Typ. Max. 6.0 Unit V 7.0 Leakage current between PL5 and Gnd at VRM =5V 7.4 1 V µA IA-PL5 Activation current between PL5 and Gnd 10 mA VON-PL5 Voltage drop on active state at ION=3A 1.3 V PROTECTION OF 12 V LINE (PL12) Symbol Parameter VBR-PL12 Breakdown voltage at IR=1mA IRM-PL12 Leakage current between PL12 and Gnd at VRM =12V Rd Dynamic resistance. Square pulse Ipp=3A, tp = 2.5µs 2/6 Value Min. Typ. 14 2.5 Max. Unit 16 V 1 µA Ω HDP01-0512N Fig. 1: Non repetitive surge peak on-state current versus pulse duration (rectangular waveform). Fig. 2: Peak pulse power dissipation versus exponential pulse duration (Tj initial = 25°C). Ppp(W) ITSM(A) 500 50 Tj initial=25°C Tj initial=25°C 100 10 10 Pl5 vs GND tp(ms) 1 1 10 100 1000 Fig. 3: Typical clamping voltage versus peak pulse current (rectangular waveform, tp=2.5µs). 0.1 1 10 100 300 Fig. 4: Thermal resistance junction to ambient versus copper surface under tab (Epoxy printed circuit board FR4, copper thickness: 35µm). Ipp(A) Rth(j-a) (°C/W) 3 130 120 110 100 90 80 70 60 50 40 30 20 10 0 2 1 0.5 PL12 vs GND Vcl(V) 0.1 15 tp(ms) Pl12 vs GND 1 0.01 16 17 18 19 20 21 22 S(Cu) (cm²) 0 1 2 3 4 5 Note: Rth(j-a) = (TjMax - Tamb) / PMax Fig. 5: Thermal impedance junction to ambient and junction to tab versus pulse duration. Zth(°C/W) 2E+2 1E+2 Zth(j-a) Zth(j-t) 1E+1 1E+0 1E-1 tp(s) 1E-2 1E-4 1E-3 1E-2 1E-1 1E+0 1E+1 1E+2 3/6 HDP01-0512N APPLICATION INFORMATION DESCRIPTION The HDP01-0512N has been specially designed to protect equipment supplied by both +5 and +12 Volt power rails such as hard disk drives, CD-ROMs, DVDs, floppy disk drives with the topology indicated in figure A.1. Fig. A.1: typical application schematic. HDP01-512N OVERVOLTAGE DETECTOR OVERVOLTAGE ELIMINATOR +12V supply rail ELECTRONIC MODULE (i.e. Disk drive) This protection device is able to protect both +5 and +12 Volts power rails against transients and rails inversion. The internal +5V protection is achieved with a crowbar structure whereas the +12V one is secured by a clamping structure. +5V supply rail ABOUT THE +5V PROTECTION In normal conditions, (region ➊ of figure A.2) the +5V protection (PL5 termination) of the HDP01-0512N connected to the +5V rail, is in idle state and its leakage current is 1µA max at +5V @ 25°C. Upon occurrence of transients, the HDP01-0512N eliminates the overvoltage by clamping up to a maximum of +7.4V (region ➋ ) since the current induced by the transient does not exceed the activation current IA min (10mA). If the IA min current value is passed, the internal +5V protection trips in crowbar mode (region ➌ ) and then a short circuit appears on the +5V rail . Fig. A.2: Current and voltage characteristic of the +5V protection. I 3 The arrows indicate the way the device is activated from point ➋ to point ➌ , and the way it goes back in idle state, point ➌ to point ➊ Thanks to this behavior the electronic module (i.e. disk drive) connected to the +5V rail is safe. IH IA 1 2 V VA As soon as the transient disappears and assuming that the current in the +5V power supply rail is under the holding current IHmin value (10mA) of the +5V protection, the HDP01-0512N gets back in idle state and the protected electronic module turns back on. As in many cases the current delivered by the +5V power supply is higher than the IH min current value of the HDP01-0512N, it is necessary to use a serial protection on the +5V rail (i.e. resettable fuse), connected before the HDP protection. This will prevent the HDP01-0512N from being damaged by an over-rated dissipated power. The choice of the serial protector is led by both peak current and current duration the HDP01-0512N is able to support. The serial protection shall fulfill the next condition : i2t serial protection < ITSM @ tp of +5V HDP protection. 4/6 HDP01-0512N The ITSM value as a function of the pulse duration tp for the HDP01 device is given on the figure 1 of this datasheet. In the case the supply cables of the +12V and +5V are reversed, the +5V (PL5) internal protection of the HDP01-512N immediately shorts circuits +5V rail and ensures on efficient protection of the electronic module. ABOUT THE +12V PROTECTION The +12V internal protection (PL12 termination) eliminates all transients appearing on the +12V supply rail. In normal conditions (region 4 of figure A.3) its leakage current is 1µA maximum at 12V @ 25°C. When a surge occurs on the +12V rail, the overvoltage is clamped (region 5) and the electronic module connected to this rail is protected. Fig. A.3: Current and voltage characteristic of the +12V protection. I The clamping voltage (Vcl) is depending on several parameters which are : - current induced by the transient (Ipp) - ambient temperature effect (αT) - breakdown voltage of the protection (VBR) - dynamic resistance of the protection (Rd) 5 4 V VCL To evaluate the clamping voltage appearing on the +12V rail when a transient occurs, the next formula is needed : Vcl = VBRmax + Rd*IPP with a typical Rd equals to 2.5Ω IPP is the peak current given by the transient which is : ⇒ Vtransient = peak voltage of the transient IPP = (Vtransient - Vcl)/Rs ⇒ Rs is the series resistance of the surge generator. If, for example, we consider a 50V combined surge 1.2/50µs - 8/20µs, as defined by the standard IEC1000-4-5, the Vcl is calculated as: RS = 42 Ω (generator impedance) Vcl = 16 + 2.5*IPP and IPP = (50 - Vcl) / 42 then it comes up with Vcl = 17.9V and IPP = 0.7A The impact of the temperature on the clamping voltage can be considered as to be : Vcl(T°C) = Vcl(25°C) * (1 + αT(T°C-25°C)) where T°C is the ambient temperature for which the module shall run. The HDP01-0512N +12V protection has a power dissipation capability that is given in the figure 2 of this datasheet named "Peak pulse power versus exponential pulse duration". This figure is necessary to determine if the power involved in the +12V protection does not exceed the maximum power the HDP01 +12V protection can support. For example, considering the last calculation where Vcl=17.9 and IPP=0.7A, the peak power is in that case 12.5W (Vcl*IPP) for a 20µs exponential surge duration. If we compare this value to the curve of figure 2, then we see the dissipated power is much lower than the +12V protection limit (200W @ 20µs) this tells us the +12V protection of the HDP01-0512N can easily withstand such a 12.5W surge. 5/6 HDP01-0512N PACKAGE MECHANICAL DATA SOT223 (Plastic) DIMENSIONS REF. Min. c A Typ. Max. 1.80 A1 B Inches Typ. Max. Min. A V A1 Millimeters 0.071 0.02 0.001 e1 B 0.60 0.70 0.80 0.024 0.027 0.031 D B1 2.90 3.00 3.10 0.114 0.118 0.122 c 0.24 0.26 0.32 0.009 0.010 0.013 D 6.30 6.50 6.70 0.248 0.256 0.264 B1 H E e e 2.3 0.090 e1 4.6 0.181 E 3.30 3.50 3.70 0.130 0.138 0.146 H 6.70 7.00 7.30 0.264 0.276 0.287 V 10° max FOOT PRINT DIMENSIONS (in millimeters) SOT223 (Plastic) MARKING Order code Marking Package Weight Packing Base Qty HDP01-0512NRL HD1 SOT223 0.123 g Tape & reel 1000pcs Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics © 1999 STMicroelectronics - Printed in Italy - All rights reserved. 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