PAM2808 document number: dsxxxxx rev. 1 - 0 1 of 8 www.diodes.com october 2012 ? diodes incorporated PAM2808 a product line o f diodes incorporated 5w high power hbled driver description the PAM2808 is a 5w high power hble d driver with 1.5a constant current. it features high efficiency and low quiescent current, making it ideal for battery powered applications. the PAM2808 features over current protection and over temperature shutdown. the PAM2808 is stable with a ceramic output capacitor of 4.7f or higher. PAM2808 is available in sop-8(ep) package. features ? high output current up to 1.5a ? low feedback voltage: 0.1v ? stable with a ceramic output capacitor ? low quiescent current ? open load led protection ? over temperature shutdown ? low temperature coefficient ? standard sop-8(ep) packages ? pb-free package pin assignments applications ? high bright led driver ? white led torch (flashlight) typical applications circuit
PAM2808 document number: dsxxxxx rev. 1 - 0 2 of 8 www.diodes.com october 2012 ? diodes incorporated PAM2808 a product line o f diodes incorporated pin description pin number pin name function 1 nc not connected 2 vin input voltage 3 en enabled 4 gnd ground 5 nc not connected 6 fb feedback 7 vout output voltage 8 nc not connected block diagram absolute maximum ratings (@t a = +25c, unless otherwise specified.) these are stress ratings only and functional operation is not implied. exposure to absolute maximum ratings for prolonged time periods may affect device reliability. all voltages are with respect to ground. parameter rating unit input pin voltage 6.5 v en, fb vout pin voltage -0.3 to v in +0.3 maximum output current p d /(v in ? v o ) ? storage temperature -65 to +150 c maximum junction temperature 150 lead soldering temperature 300
PAM2808 document number: dsxxxxx rev. 1 - 0 3 of 8 www.diodes.com october 2012 ? diodes incorporated PAM2808 a product line o f diodes incorporated recommended operating conditions (@t a = +25c, unless otherwise specified.) parameter rating unit maximum supply voltage 6 v junction temperature range -40 to +125 c ambient temperature range -40 to +85 thermal information parameter symbol package max unit thermal resistance (junction to case) jc sop-8(ep) 11 c/w thermal resistance (junction to ambient) ja sop-8(ep) 90 electrical characteristics (@t a = +25c, v in = 4.5v, c in = 4.7f, c o = 4.7f, unless otherwise specified.) parameter symbol test conditions min typ max units input voltage range v in 2.5 6.0 v fb reference voltage v ref 0.1 v output current i o r s = 0.3 ? 330 ma r s = 0.14 ? 700 r s = 0.1 ? 1000 r s = 0.067 ? 1500 over temperature shutdown ots 150 c over temperature hysteresis oth 40 c en input high threshold v eh v in = 2.5v to 5v 1.5 v en input low threshold v el v in = 2.5v to 5v 0.3 v shutdown current i sd v en = 0v 1 a
PAM2808 document number: dsxxxxx rev. 1 - 0 4 of 8 www.diodes.com october 2012 ? diodes incorporated PAM2808 a product line o f diodes incorporated typical performance characteristics (@t a = +25c, c in = 4.7f, c o = 4.7f, unless otherwise specified.)
PAM2808 document number: dsxxxxx rev. 1 - 0 5 of 8 www.diodes.com october 2012 ? diodes incorporated PAM2808 a product line o f diodes incorporated application information external capacitor requirements a 4.7 f or larger ceramic input bypass capacitor, connected between v in and gnd and located close to the PAM2808, is required for stability. a 4.7f minimum value capacitor from v o to gnd is also required. to improve transient response, noise rejection, and ripple rejection, an additional 10 f or larger, low esr capacitor is recommended at the output. a hi gher-value, low esr output capacitor may be necessary if large , fast-rise-time load transients are anticipated and the device is located several inches fr om the power source, especially if th e minimum input voltage of 2.5v is used. regulator protection the PAM2808 features internal current limiti ng, thermal protection and short circuit pr otection. during normal operation, the p am2808 limits output current to about 2.5a. when current limiting engages, the ou tput voltage scales back linearly until the over current con dition ends. while current limiting is designed to prevent gross device failure, care should be taken not to exc eed the power dissipation ratings of the package. if the temperature of the device exceeds +150c, th ermal-protection circuitry will shut down. once the device has cooled down to appro ximately +40c below the high temp trip point, regulator operation resumes. thermal information the amount of heat generates is: () i v v p o o in d ? = all integrated circuits have a maximu m allowable junction temperature (t j max ) above which normal operation is not assured. a system designer must design the operating environment so that the operating junction temperature (t j ) does not exceed the maximum junction temperature (t j max ). the two main environmental variables that a designer can use to improve thermal perfo rmance are air flow and external heat s inks. the purpose o f this information is to aid t he designer in determining the proper operat ing environment for a linear regulator that is operating at a specific power level. in general, the maximum expected power (p d(max) ) consumed by a linear regulator is computed as: ( ) + ? = where: v i(avg) is the average input voltage. v o(avg) is the average output voltage. i o(avg) is the average output current. i (q) is the quiescent current. the quiescent current is insignificant compared to the average output current; therefore, the term v i(avg) x i (q) can be neglected. the operating junction temperature is computed by adding the ambient temperature (t a ) and the increase in temperature due to the regulator's power dissipation. the temperature rise is comput ed by multiplying the maximum expected power dissipation by the sum of the thermal r esistances between the junction and the case (r jc ), the case to heatsink (r js ), and the heatsink to ambient (r ja ). thermal resistances are measures of how effectively an object dissipates heat. typically, the larger the device, the more surface area available for power dissipat ion so that the object?s thermal resistance will be lower.
PAM2808 document number: dsxxxxx rev. 1 - 0 6 of 8 www.diodes.com october 2012 ? diodes incorporated PAM2808 a product line o f diodes incorporated ordering information part number marking package type standard package PAM2808blbr p2808 xxxyw sop-8(ep) 2500 units/tape&reel marking information
PAM2808 document number: dsxxxxx rev. 1 - 0 7 of 8 www.diodes.com october 2012 ? diodes incorporated PAM2808 a product line o f diodes incorporated package outline dimensions (all dimensions in mm.) sop-8(ep)
PAM2808 document number: dsxxxxx rev. 1 - 0 8 of 8 www.diodes.com october 2012 ? diodes incorporated PAM2808 a product line o f diodes incorporated important notice diodes incorporated makes no warranty of any kind, express or implied, with regards to this document, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose (and their equivalents under the laws of any jurisdiction). diodes incorporated and its subsidiaries reserve the right to ma ke modifications, enhancements, im provements, corrections or ot her changes without further notice to this document and any product described herein. diodes incorporated does not assume any liability ari sing out of the application or use of this document or any product described herein; neither does diodes incorporated convey any license under its patent or trademark rights, nor the rights of others. any customer or us er of this document or products described herein in such applica tions shall assume all risks of such use and will agree to hold diodes incorporat ed and all the companies whose products are represented on diodes incorporated website, harmless against all damages. diodes incorporated does not warrant or accept any liability wh atsoever in respect of any products purchased through unauthoriz ed sales channel. should customers purchase or use diodes inco rporated products for any unintended or unauthorized application, customers shall i ndemnify and hold diodes incorporated and its representat ives harmless against all claims, damages, expenses, and attorney fees arising out of, directly or indirectly, any claim of personal injury or death a ssociated with such unintended or unauthorized application. products described herein may be covered by one or more united states, international or foreign patents pending. product names and markings noted herein may also be covered by one or more united states, international or foreign trademarks. this document is written in english but may be translated into mu ltiple languages for reference. only the english version of t his document is the final and determinative format released by diodes incorporated. life support diodes incorporated products are specifically not authorized for use as critical comp onents in life support devices or systems without the express written approval of the chief executive offi cer of diodes incorporated. as used herein: a. life support devices or syst ems are devices or systems which: 1. are intended to implant into the body, or 2. support or sustain life and whose failure to perform when proper ly used in accordance with inst ructions for use provided in the labeling can be reasonably expected to result in significant injury to the user. b. a critical component is any component in a life support devic e or system whose failure to perform can be reasonably expect ed to cause the failure of the life support device or to affect its safety or effectiveness. customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support dev ices or systems, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning the ir products and any use of diodes incorporated products in such safety-critica l, life support devices or systems, notwithstanding any devices- or systems-related information or support that may be provided by diodes incorporated. further, customers must fully indemnify diodes incorporate d and its representatives against any damages arising out of the use of diodes incorporated products in such safety-critical, life suppor t devices or systems. copyright ? 2012, diodes incorporated www.diodes.com
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