u Cellular Handsets & Accessories u Portable Instrumentation u Keypads, Side Keys, LCD Displays u Notebooks & Desktop Computers u MP3 Players

Transcription

1 P OTECTION PRODUCTS Ò D! The µclamp series of Transient Voltage Suppressors (TVS) are designed to replace multilayer varistors (MLVs) in portable applications such as cell phones, notebook computers, and PDAs. They offer superior electrical characteristics such as lower clamping voltage and no device degradation when compared to MLVs. They are designed to protect sensitive semiconductor components from damage or upset due to electrostatic discharge (ESD), lightning, electrical fast transients (EFT), and cable discharge events (CDE). The µclamp 3T is constructed using Semtech s proprietary EPD process technology. The EPD process provides low standoff voltages with significant reductions in leakage currents and capacitance over siliconavalanche diode processes. They feature a true operating voltage of 3.3 volts for superior protection when compared to traditional pn junction devices. The µclamp3t is in a -pin SLP6PT package. It measures. x.6 x.4. The leads are spaced at a pitch of.65 and are finished with lead-free NiPdAu. Each device will protect one line operating at 3.3 volts. It gives the designer the flexibility to protect single lines in applications where arrays are not practical. They may be used to meet the ESD iunity requirements of IEC The combination of small size and high ESD surge capability makes them ideal for use in portable applications such as cellular phones, digital cameras, and MP3 players. F"# A+"! uclamp3t Low Profile µclamp -Line ESD protection u Transient protection for data lines to IEC 6-4- (ESD) ±3kV (air), ±3kV (contact) IEC (EFT) 4A (tp = 5/5ns) Cable Discharge Event (CDE) u Ultra-small package (. x.6 x.4) u Protects one data line u Low reverse current: na typical (VR=3.3V) u Working voltage: 3.3V u Low leakage current u Solid-state silicon-avalanche technology M%"!"+ (%"" u SLP6PT package u Pb-Free, Halogen Free, RoHS/WEEE Compliant u Nominal Dimensions:. x.6 x.4 u Lead Finish: NiPdAu u Molding compound flaability rating: UL 94V- u Marking : Marking code u Packaging : Tape and Reel u Cellular Handsets & Accessories u Portable Instrumentation u Keypads, Side Keys, LCD Displays u Notebooks & Desktop Computers u MP3 Players D$!! S%$" & '! (!)*#"! Revision 4/8/5 Nominal Dimensions () SLP6PT (Bottom View)

2 uclamp3t, ,-58976:,-./3-4 KGBILN Rating Symbol Value Units Peak Pulse Power (tp = 8/µs) M aximum Peak Pulse Current ( tp = 8/µs) P pk 4 Watts I pp 5 Amps ESD per IEC 6-4- (Air) SD per IEC 6-4- (Contact) E V ESD +/- 3 +/- 3 kv Operating Temperature T J -4 to +85 C Storage Temperature T STG 55 to +5 - C O?CQBRIQG? TUGRGQBCRI=BIQ= VWXYZ o C) Parameter Symbol Conditions Minimum Typical Maximum Units Reverse Stand-Off Voltage V WM R. 3 3 V Punch-Through Snap-Back Voltage Voltage V PT V SB I PT I SB = µ A V = 5mA. 8 V Reverse Leakage Current I R V RWM = 3.3V..5 µ A Clamping Voltage V C I PP = A, tp = 8/µ s 6. 5 V Clamping Voltage V C I PP = 5A, tp = 8/µ s 8 V ESD Clamping Voltage V C I P P = 4A, tlp =./ns ESD Clamping Voltage V C I P P = 6A, tlp =./ns 5.6 V 8.6 V, 3 Dynamic Resistance R DYN tlp =. / n s.5 Ohms I/O pin to Gnd Junction Capacitance C j = V, f = MHz V R 5 7 pf Notes )ESD gun return path connected to ESD ground plane. )Transmission Line Pulse Test (TLP) Settings: t p = ns, t r =.ns, I TLP and V TLP averaging window: t = 7ns to t = 9ns. 3) Dynamic resistance calculated from I pp = 4A to I pp = 6A 5 Semtech Corporation

3 uclamp3t [\de]fe_da [\dghfei jypical Characteristics Non-Repetitive Peak Pulse Power vs. Pulse Time [\]^_`_ab\c Clamping Voltage vs. Peak Pulse Current 9 Peak Pulse Power - P PP (W). Pulse Duration - tp (µs) Clamping Voltage - V C (V) DR Peak Pulse Current - I PP (A) Waveform Parameters: tr = 8µs td = µs Normalized Capacitance vs. Reverse Voltage TLP Characteristic.6.4. f = MHz 5 Transmission Line Pulse Test (TLP) Settings: t p = ns, t r =.ns, I TLP and V TLP averaging window: t = 7ns to t = 9ns Cj(VR) / Cj(VR=V) TLP Current (A) Reverse Voltage - V R (V) TLP Voltage (V) ESD Clamping (+8kV Contact per IEC 6-4-) ESD Clamping (-8kV Contact per IEC 6-4-) Measured with 5 Ohm scope input impedance, GHz bandwidth. Corrected for 5 Ohm, db attenuator. ESD gun return path connected to ESD ground plane Voltage (V) 3 5 Voltage (V) Measured with 5 Ohm scope input impedance, GHz bandwidth. Corrected for 5 Ohm, db attenuator. ESD gun return path connected to ESD ground plane Time (ns) Time (ns) 5 Semtech Corporation 3

4 uclamp3t kltumvuotq kltwxvuy zypical Characteristics klmnopoqrls Typical Insertion Loss (S) CH S LOG 6 db / REF db : -.35 db 8 MHz db : -.59 db 9 MHz -6 db - db -8 db : db MHz 4: db.8 GHz -4 db 5: -.95 db.5 GHz -3 db -36 db MHz MHz MHz GHz 3 GHz START. 3 MHz STOP 3. MHz { }~ ~ ƒ ƒ ˆ ~ ƒ Device Connection Options The µclamp3t is designed to protect one data line operating up to 3.3 volts. It will present a high impedance to the protected line up to 3.3 volts. It will turn on when the line voltage exceeds 3.5 volts. The device is bidirectional and may be used on lines where the signal polarity is above and below ground. These devices are not recoended for use on dc power supply lines due to their snap-back voltage characteristic. Circuit Board Layout Recoendations for Suppression of ESD. Good circuit board layout is critical for the suppression of ESD induced transients. The following guidelines are recoended: Place the TVS near the input terminals or connectors to restrict transient coupling. Minimize the path length between the TVS and the protected line. Minimize all conductive loops including power and ground loops. The ESD transient return path to ground should be kept as short as possible. Never run critical signals near board edges. Use ground planes whenever possible. Device Schematic & Pin Configuration 5 Semtech Corporation 4

5 Š Š š œ ž Ÿ Ÿ ž Ÿ ech Low Voltage TVS Conventional TVS diodes are silicon avalanche, p-n junction devices designed to operate at voltages as low as 5 volts. However, many of today's semiconductor devices operate at voltages below 5 volts, and thus require lower voltage protection devices. Unfortunately, for operating voltages below 5 volts, conventional TVS diode technology becomes impractical. This is due to the adverse effects of high leakage current and high capacitance caused by the high impurity concentrations that are needed to lower the device voltage below 5 volts. Semtech's proprietary low voltage EPD device technology was developed to provide protection for today's circuits operating at voltages below 5 volts. Unlike conventional TVS diodes, the EPD device utilizes a complex four layer (n-p-p-n) structure. The construction of these devices results in very low operating voltage without the adverse effects mentioned above. uclamp3t Š Œ Ž Š Device Operation Since the EPD TVS devices use a 4-layer structure, they exhibit a slightly different IV characteristic curve when compared to conventional devices. Figure compares the IV characteristic curves of a low voltage TVS with a working voltage (V RWM ) of 3.3 volts to a conventional device with a working voltage of 5 volts. During normal operation, each device represents a high-impedance to the circuit up to its working voltage. During an ESD event, they will begin to conduct and will enter a low impedance state. For the 3.3 volt device, this happens when the punch-through voltage (V PT ) is exceeded. Unlike a conventional 5 volt device, the low voltage TVS will exhibit a slight negative resistance characteristic as it conducts current. This characteristic aids in lowering the clamping voltage of the device. However, the device can latch up if a DC bias voltage is present. The reason being that in order for the device to turn off, the voltage must fall below the snap-back voltage (V SB ). This value is normally a minimum of.8 volts. If the device is biased above the.8 volts, it will never fall below the snap-back voltage and will therefore stay in a conducting state. Low Voltage TVS Working Voltage (V RWM ): Maximum rated operating voltage at which the device will appear as a high impedance to the protected circuit. Punch-Through Voltage (V PT ): Minimum rated voltage at which the device will become a low impedance (i.e. Minimum Turn-On Voltage). When V PT is exceeded, the device will conduct. Snap-Back Voltage (V SB ): Minimum rated voltage when the device is in a conducting state measured at I SB = 5mA. This voltage is less than the working voltage. The voltage must fall below V SB for the device to turn off. Clamping Voltage (V C ): Maximum voltage drop across the device at a defined peak pulse current (I PP ). This is the voltage seen by the protected circuit during a transient event. Current - I (A) Semtech 3.3 Volt TVS V PT V RWM V SB V RWM Voltage - V (V) V BR Semtech 5 Volt TVS Figure volt vs. 5 volt TVS IV Curve 5 Semtech Corporation 5

6 uclamp3t ª«³ µ ³ ª«³ µ ¹ºº»¼½¾ ¼ÀÁ ÃÁÄÀÅƾ ¼ÀÁ Ç Èº¼½É ÊÀËÉ» ª«±«² uclamp3t Spice Model uclamp3t Spice Parameters Parameter IS BV VJ RS IBV CJO TT U nit D (TVS) D (TVS) Amp E- E- Volt Volt Ohm.. Farad E- E- Amp E-3 E-3 sec.54e- 9.54E- 9 M N --.. EG ev.. 5 Semtech Corporation 6

7 ÌÍÖ ÎØ ÐÖÓ ÌÍÖÙÚØ Û ÜÝÞßàáâãäåæàáç ãäåwing è - éüèê SLP6PT uclamp3t ÌÍÎÏÐÑÐÓÔÍÕ A D B aaa C A TOP VIEW A E C SEATING PLANE DIMENSIONS DIM MIN INCHES MILLIMETERS NOM MAX MIN NOM MAX A A b D E e.6 BSC.65 BSC L R N aaa.3.8 bbb.4. PIN ID bxn bbb C A B R e BOTTOM VIEW x L NOTES:. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). ëåáì íattern - SLP6PT (C) G Z X Y DIMENSIONS DIM INCHES MILLIMETERS C (.33) (.85) G X Y..55 Z.55.4 NOTES:. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. 5 Semtech Corporation 7

8 uclamp3t îï øðùøò ô îï úûùøü îïðñòóòôõïö ýþÿm Oÿ ÿ ÿþ Notes: ) Device is electrically syetrical ) Marking will also include line matrix date code Part Number Qty per Reel Reel Size uclamp3t.tct 3, 7 Inch uclamp3t.tnt, 7 Inch MicroClamp, uclamp and µclamp are trademarks of Semtech Corporation þÿÿ ÿ Cape Specification 3 Pin Location (Towards Sprocket Holes) Device Orientation in Tape A B K.69 +/-..9 +/ /-. Tape Width B, (Max) D D E F P P P T W 8 4. (.65) ( ).4 ±.5 (.).75±. (.69±.4) 3.5±.5 (.38±.) 4.±. (.57±.- 4) 4.±. (.57±.- 4).±.5 (.79±.).54±. (.6) (.±.) 5 Semtech Corporation 8

9 uclamp3t P P!", piece, Pitch Reel P Bo Ko Ao A B K.7 +/ / /-.5 Note: All dimensions in unless otherwise specified Pin Location (Towards Sprocket Holes) Device Orientation in Tape #$%&'(& )%*$+,'&-$% Semtech Corporation Protection Products Division Flynn Road, Camarillo, CA 93 Phone: (85)498- FAX (85) Semtech Corporation 9