MAXIM MAX1951

MAX1951ESA
Rev. A
RELIABILITY REPORT
FOR
MAX1951ESA
PLASTIC ENCAPSULATED DEVICES
May 14, 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 MAX1951 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
V. ........Quality Assurance Information
VI. .......Reliability Evaluation
IV. .......Die Information
.....Attachments
I. Device Description
A. General
The MAX1951 high-efficiency, DC-to-DC step-down switching regulator delivers up to 1.5A of output current. The
device operates from an input voltage range of 2.6V to 5.5V and provides an output voltage from 0.8V to VIN, making
the MAX1951 ideal for on-board postregulation applications. The MAX1951 total output error is less than 1% over
load, line, and temperature.
The MAX1951 operates at a fixed frequency of 1MHz with an efficiency of up to 94%. The high operating frequency
minimizes the size of external components. Internal soft-start control circuitry reduces inrush current. Short-circuit
and thermal-overload protection improve design reliability.
The MAX1951 provides an adjustable output from 0.8V to VIN. The device ia available in a space-saving 8-pin SO
package.
B. Absolute Maximum Ratings
Item
IN, VCC to GND
COMP, FB, REF to GND
LX to Current (Note 1)
PGND to GND
Operating Temperature Range
Junction Temperature Range
Storage Temperature Range
Lead Temperature (soldering, 10s)
Continuous Power Dissipation (TA = +70°C)
8-Pin SO
Derates above +70°C
8-Pin SO
Rating
-0.3V to +6V
-0.3V to (VCC + 0.3V)
±4.5A
Internally Connected
-40°C to +85°C
-40°C to +150°C
-65°C to +150°C
+300°C
976mW
12.12mW/°C
II. Manufacturing Information
A. Description/Function: 1MHz, All-Ceramic, 2.6V to 5.5V Input,1.5A PWM Step-Down DC-to-DC Regulators
B. Process:
S8 (Standard 0.8 micron silicon gate CMOS)
C. Number of Device Transistors:
2500
D. Fabrication Location:
California, USA
E. Assembly Location:
Philippines or Thailand
F. Date of Initial Production:
September, 2002
III. Packaging Information
A. Package Type:
8-Pin SO
B. Lead Frame:
Copper
C. Lead Finish:
Solder Plate
D. Die Attach:
Silver-filled Epoxy
E. Bondwire:
Gold (2 mil dia.)
F. Mold Material:
Epoxy with silica filler
G. Assembly Diagram:
# 05-3501-0029
H. Flammability Rating:
Class UL94-V0
I. Classification of Moisture Sensitivity
per JEDEC standard JESD22-112:
Level 1
.
IV. Die Information
A. Dimensions:
80 x 90 mils
B. Passivation:
Si3N4/SiO2 (Silicon nitride/ Silicon dioxide)
C. Interconnect:
Aluminum/Si (Si = 1%)
D. Backside Metallization:
None
E. Minimum Metal Width:
0.8 microns (as drawn)
F. Minimum Metal Spacing:
0.8 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)
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
192 x 4389 x 45 x 2
(Chi square value for MTTF upper limit)
Temperature Acceleration factor assuming an activation energy of 0.8eV
λ = 24.13 x 10-9
λ = 24.13 F.I.T. (60% confidence level @ 25°C)
This low failure rate represents data collected from Maxim’s reliability monitor program. In addition to
routine production Burn-In, Maxim pulls a sample from every fabrication process three times per week and subjects
it to an extended Burn-In prior to shipment to ensure its reliability. The reliability control level for each lot to be
shipped as standard product 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 any lot that exceeds this reliability control level. Attached Burn-In
Schematic (Spec. # 06-5972) shows the static Burn-In circuit. Maxim also performs quarterly 1000 hour life test
monitors. This data is published in the Product Reliability Report (RR-1M).
B. Moisture Resistance Tests
Maxim pulls pressure pot samples from every assembly process three times per week. Each lot sample
must meet an LTPD = 20 or less before shipment as standard product. Additionally, the industry standard
85°C/85%RH testing is done per generic device/package family once a quarter.
C. E.S.D. and Latch-Up Testing
The PM43 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
MAX1951ESA
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
45
0
77
77
0
0
0
Moisture Testing (Note 2)
Pressure Pot
Ta = 121°C
P = 15 psi.
RH= 100%
Time = 168hrs.
DC Parameters
& functionality
SO
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 DIP 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
TERMINAL D
Mil Std 883D
Method 3015.7
Notice 8
R = 1.5kΩ
C = 100pf
CURRENT
PROBE
(NOTE 6)
ONCE PER BOARD
ONCE PER SOCKET
4.7 OHMS
+5V
1
8
2
7
3
6
10 K
1 uF
4
0.1 uF
100 uF
5
100 K
100 pF
1 uF
DEVICES: MAX1951/1952
PACKAGE: 8-NSO
MAX. EXPECTED CURRENT = 10 mA
DOCUMENT I.D. 06-5972
REVISION B
DRAWN BY: TEK TAN
NOTES:
MAXIM
TITLE: BI
Circuit (MAX1951/1952)
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