MAX1887EEE Rev. A RELIABILITY REPORT FOR MAX1887EEE PLASTIC ENCAPSULATED DEVICES March 6, 2003 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 MAX1887 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 MAX1887 step-down slave controller is intended for low-voltage, high-current, multiphase DC-to-DC applications. The MAX1887 slave controller can be combined with any of Maxim's Quick-PWM™ step-down controllers to form a multiphase DC-to-DC converter. Existing Quick-PWM controllers, such as the MAX1718, function as the master controller, providing accurate output voltage regulation, fast transient response, and fault protection features. Synchronized to the master's low-side gate driver, the MAX1887 includes the Quick-PWM constant on-time controller, gate drivers for a synchronous rectifier, active current balancing, and precision current-limit circuitry. The MAX1887 provides the same high efficiency, ultra-low duty factor capability, and excellent transient response as other Quick-PWM controllers. The MAX1887 differentially senses the inductor currents of both the master and the slave across current-sense resistors. These differential inputs and the adjustable current-limit threshold derived from an external reference allow the slave controller to accurately balance the inductor currents and provide precise current-limit protection. The MAX1887's dual-purpose current-limit input also allows the slave controller to automatically enter a low-power standby mode when the master controller shuts down. The MAX1887 triggers on the rising edge of the master's low-side gate driver, which staggers the on-times of both master and slave, providing out-of-phase operation that can reduce the input ripple current and consequently the number of input capacitors. B. Absolute Maximum Ratings Item V+ to GND VCC, VDD to GND PGND to GND TRIG, LIMIT to GND ILIM, CM+, CM-, CS+, CS-, COMP to GND DL to PGND BST to GND DH to LX LX to BST Operating Temperature Range Junction Temperature Storage Temperature Range Lead Temperature (soldering, 10s) Continuous Power Dissipation (TA = +70°C) 16-Pin QSOP Derates above +70°C 10-Pin uMAX Rating -0.3V to +30V -0.3V to +6V ±0.3V -0.3V to +6V -0.3V to (VCC + 0.3V) -0.3V to (VDD + 0.3V) -0.3V to +36V -0.3V to (VBST + 0.3V) -6V to +0.3V -40°C to +85°C +150°C -65°C to +150°C +300°C 667mW 8.3mW/°C II. Manufacturing Information A. Description/Function: Quick-PWM Slave Controllers for Multiphase, Step-Down Supplies B. Process: S12 – Silicon Gate 1.2 micron CMOS C. Number of Device Transistors: 1422 D. Fabrication Location: Oregon or California, USA E. Assembly Location: Malaysia, Thailand or Philippines F. Date of Initial Production: October, 2001 III. Packaging Information A. Package Type: 16-Lead QSOP B. Lead Frame: Copper C. Lead Finish: Solder Plate D. Die Attach: Silver-filled epoxy E. Bondwire: Gold (1.3 mil dia.) F. Mold Material: Epoxy with silica filler G. Bonding Diagram 05-3801-0006 H. Flammability Rating: Class UL94-V0 I. Classification of Moisture Sensitivity per JEDEC standard JESD22-A112: Level 1 IV. Die Information A. Dimensions: 86 x 91 mils B. Passivation: Si3N4/SiO2 (Silicon nitride/ Silicon dioxide) C. Interconnect: Aluminum 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: B. Outgoing Inspection Level: Jim Pedicord (Reliability Lab Manager Bryan Preeshl (Executive Director of QA) Kenneth Huening (Vice President) 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 80 x 2 Temperature Acceleration factor assuming an activation energy of 0.8eV λ = 13.57 x 10-9 λ = 13.57 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 rf om 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. # 06-5881) 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 PD13 die type has been found to have all pins able to withstand a transient pulse of ±2000V, per MilStd-883 Method 3015 (reference attached ESD Test Circuit). Latch-Up testing has shown that this device withstands a current of ±250mA. Table 1 Reliability Evaluation Test Results MAX1887EEE TEST ITEM TEST CONDITION Static Life Test (Note 1) Ta = 135°C Biased Time = 192 hrs. FAILURE IDENTIFICATION PACKAGE DC Parameters & functionality SAMPLE SIZE NUMBER OF FAILURES 80 0 77 0 0 Moisture Testing (Note 2) Pressure Pot Ta = 121°C P = 15 psi. RH= 100% Time = 168hrs. DC Parameters & functionality QSOP 85/85 Ta = 85°C RH = 85% Biased Time = 1000hrs. DC Parameters & functionality 77 DC Parameters 77 Mechanical Stress (Note 2) Temperature Cycle -65°C/150°C 1000 Cycles Method 1010 Note 1: Life Test Data may represent plastic D.I.P. qualification lots. Note 2: Generic package/process data 0 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 Mil Std 883D Method 3015.7 Notice 8 TERMINAL D R = 1.5kΩ Ω C = 100pf CURRENT PROBE (NOTE 6) ONCE PER SOCKET ONCE PER BOARD 6.2 OHMS +5V 47 K 0.1 uF 10 K 4.7 K +20V 15 K 0.1 uF 20 19 18 17 0.1 uF 16 1 15 2 14 3 13 4 12 5 11 6 7 8 9 10 DEVICES: MAX 1897 PACKAGE: 20-QFN MAX. EXPECTED CURRENT = 2mA (+5V), 0.1mA (+20V) DOCUMENT I.D. 06-5881 REVISION A MAXIM TITLE: BI Circuit (MAX1897) DRAWN BY: TEK TAN NOTES: PAGE 2 OF 3