MAX1644EAE Rev. A RELIABILITY REPORT FOR MAX1644EAE PLASTIC ENCAPSULATED DEVICES February 11, 2002 MAXIM INTEGRATED PRODUCTS 120 SAN GABRIEL DR. SUNNYVALE, CA 94086 Written by Reviewed by Jim Pedicord Quality Assurance Reliability Lab Manager Bryan J. Preeshl Quality Assurance Executive Director Conclusion The MAX1644 successfully meets the quality and reliability standards required of all Maxim products. In addition, Maxim’s continuous reliability monitoring program ensures that all outgoing product will continue to meet Maxim’s quality and reliability standards. Table of Contents I. ........Device Description II. ........Manufacturing Information III. .......Packaging Information IV. .......Die Information V. ........Quality Assurance Information VI. .......Reliability Evaluation ......Attachments I. Device Description A. General The MAX1644 constant-off-time, PWM step-down DC-DC converter is ideal for use in applications such as PC cards, CPU daughter cards, and desktop computer bus-termination boards. The device features internal synchronous rectification for high efficiency and reduced component count. It requires no external Schottky diode. The internal 0.10 PMOS power switch and 0.10 NMOS synchronous-rectifier switch easily deliver continuous load currents up to 2A. The MAX1644 produces a preset +3.3V or +2.5V output voltage or an adjustable output from +1.1V to VIN. It achieves efficiencies as high as 95%. The MAX1644 uses a unique current-mode, constant-off-time, PWM control scheme, which includes an Idle Modeª to maintain high efficiency during light-load operation. The programmable constant-off-time architecture sets switching frequencies up to 350kHz, allowing the user to optimize performance trade-offs between efficiency, output switching noise, component size, and cost. The device also features an adjustable soft-start to limit surge currents during start-up, a 100% duty cycle mode for low-dropout operation, and a low-power shutdown mode that disconnects the input from the output and reduces supply current below 1µA. The MAX1644 is available in a 16-pin SSOP package. B. Absolute Maximum Ratings Item Vcc, IN to GND IN to VCC PGND to GND LX to PGND All other Pins to GND Continuous LX Output Current REF Short Circuit to GND Duration Storage Temp. Lead Temp. (10 sec.) Continuous Power Dissipation (TA = +70°C) 16-Pin SSOP Derates above +70°C (part mounted on 1 in2 of 1 oz. Copper) 16-Pin SSOP Rating -0.3V to +6V +/-0.3V +/-0.3V -0.3V to (VIN + 0.3V) -0.3V to (VCC + 0.3V) 2.5A Continuous -65°C to +150°C +300°C 1.2W 16.7mW/°C II. Manufacturing Information A. Description: 2A, Low-Voltage, Step-Down Regulator w/ Synchronous Rectification & Internal Switches B. Process: S12 (Standard 1.2 micron silicon gate CMOS) C. Number of Device Transistors: 1840 D. Fabrication Location: Oregon or California, USA E. Assembly Location: Philippines F. Date of Initial Production: June, 1999 III. Packaging Information A. Package Type: 16-Lead SSOP B. Lead Frame: Copper C. Lead Finish: Solder Plate D. Die Attach: Silver-filled Epoxy E. Bondwire: Gold (2.0 mil dia.) F. Mold Material: Epoxy with silica filler G. Assembly Diagram: Buildsheet # 05-1101-0105 H. Flammability Rating: Class UL94-V0 I. Classification of Moisture Sensitivity per JEDEC standard JESD22-A112: Level 1 IV. Die Information A. Dimensions: 121 x 132 mils B. Passivation: Si3N4/SiO2 (Silicon nitride/ Silicon dioxide) C. Interconnect: Aluminum/Si (Si = 1%) D. Backside Metallization: None E. Minimum Metal Width: 1.2 microns (as drawn) F. Minimum Metal Spacing: 1.2 microns (as drawn) G. Bondpad Dimensions: 5 mil. Sq. H. Isolation Dielectric: SiO2 I. Die Separation Method: Wafer Saw V. Quality Assurance Information A. Quality Assurance Contacts: Jim Pedicord (Reliability Lab Manager) Bryan Preeshl (Executive Director of QA) Kenneth Huening (Vice President) B. Outgoing Inspection Level: 0.1% for all electrical parameters guaranteed by the Datasheet. 0.1% For all Visual Defects. C. Observed Outgoing Defect Rate: < 50 ppm D. Sampling Plan: Mil-Std-105D VI. Reliability Evaluation A. Accelerated Life Test The results of the 135°C biased (static) life test are shown in Table 1. Using these results, the Failure Rate (λ) is calculated as follows: λ= 1 = MTTF 1.83 (Chi square value for MTTF upper limit) 192 x 4389 x 239 x 2 Temperature Acceleration factor assuming an activation energy of 0.8eV λ = 4.54 x 10-9 λ = 4.54 F.I.T. (60% confidence level @ 25°C) This low failure rate represents data collected from Maxim’s reliability qualification and monitor programs. Maxim also performs weekly Burn-In on samples from production to assure reliability of its processes. The reliability required for lots which receive a burn-in qualification is 59 F.I.T. at a 60% confidence level, which equates to 3 failures in an 80 piece sample. Maxim performs failure analysis on rejects from lots exceeding this level. The attached Burn-In Schematic (Spec. # 06-5250) shows the static circuit used for this test. Maxim also performs 1000 hour life test monitors quarterly for each process. This data is published in the Product Reliability Report (RR1M). B. Moisture Resistance Tests Maxim evaluates pressure pot stress from every assembly process during qualification of each new design. Pressure Pot testing must pass a 20% LTPD for acceptance. Additionally, industry standard 85°C/85%RH or HAST tests are performed quarterly per device/package family. C. E.S.D. and Latch-Up Testing The PX05 die type has been found to have all pins able to withstand a transient pulse of ±1500V, per MilStd-883 Method 3015 (reference attached ESD Test Circuit). Latch-Up testing has shown that this device withstands a current of ±250mA and/or ±20V. Table 1 Reliability Evaluation Test Results MAX1644EAE TEST ITEM TEST CONDITION Static Life Test (Note 1) Ta = 135°C Biased Time = 192 hrs. FAILURE IDENTIFICATION SAMPLE SIZE NUMBER OF FAILURES DC Parameters & functionality 239 0 Moisture Testing (Note 2) Pressure Pot Ta = 121°C P = 15 psi. RH= 100% Time = 168hrs. DC Parameters & functionality 340 1 85/85 Ta = 85°C RH = 85% Biased Time = 1000hrs. DC Parameters & functionality 77 0 DC Parameters 77 Mechanical Stress (Note 2) Temperature Cycle -65°C/150°C 1000 Cycles Method 1010 0 Note 1: Life Test Data may represent plastic D.I.P. qualification lots for the Small Outline package. Note 2: Generic Package/Process data Attachment #1 TABLE II. Pin combination to be tested. 1/ 2/ Terminal A (Each pin individually connected to terminal A with the other floating) Terminal B (The common combination of all like-named pins connected to terminal B) 1. All pins except VPS1 3/ All VPS1 pins 2. All input and output pins All other input-output pins 1/ Table II is restated in narrative form in 3.4 below. 2/ No connects are not to be tested. 3/ Repeat pin combination I for each named Power supply and for ground (e.g., where VPS1 is VDD, VCC, VSS, VBB, GND, +VS, -VS, VREF, etc). 3.4 Pin combinations to be tested. a. Each pin individually connected to terminal A with respect to the device ground pin(s) connected to terminal B. All pins except the one being tested and the ground pin(s) shall be open. b. Each pin individually connected to terminal A with respect to each different set of a combination of all named power supply pins (e.g., VSS1, or VSS2 or VSS3 or VCC1 , or VCC2 ) connected to terminal B. All pins except the one being tested and the power supply pin or set of pins shall be open. c. Each input and each output individually connected to terminal A with respect to a combination of all the other input and output pins connected to terminal B. All pins except the input or output pin being tested and the combination of all the other input and output pins shall be open. TERMINAL C R1 R2 S1 TERMINAL A REGULATED HIGH VOLTAGE SUPPLY S2 C1 DUT SOCKET SHORT TERMINAL B TERMINAL D Mil Std 883D Method 3015.7 Notice 8 R = 1.5kΩ Ω C = 100pf CURRENT PROBE (NOTE 6)