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

V. ........Quality Assurance Information

II. ........Manufacturing Information

VI. .......Reliability Evaluation

III. .......Packaging Information

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 V

, 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 V

. The device ia available in a space-saving 8-pin SO

package.

B. Absolute Maximum Ratings

Item

Rating

IN, VCC to GND

-0.3V to +6V

COMP, FB, REF to GND

-0.3V to (VCC + 0.3V)

LX to Current (Note 1)

ą4.5A

PGND to GND

Internally Connected

Operating Temperature Range

-40°C to +85°C

Junction Temperature Range

-40°C to +150°C

Storage Temperature Range

-65°C to +150°C

Lead Temperature (soldering, 10s)

+300°C

Continuous Power Dissipation (TA = +70°C)
8-Pin SO

976mW

Derates above +70

8-Pin SO

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:

/SiO

(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:

SiO

I. Die Separation Method:

Wafer Saw

V. Quality Assurance Information

A. Quality Assurance Contacts:

Jim Pedicord (Reliability Lab Manager)

Bryan Preeshl (Executive Director)

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 (

) is calculated as follows:

= 1 = 1.83 (Chi square value for MTTF upper limit)

MTTF

192 x 4389 x 45 x 2

Temperature Acceleration factor assuming an activation energy of 0.8eV

= 24.13 x 10

-9

= 24.13 F.I.T. (60% confidence level @ 25

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 Mil-

Std-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

FAILURE

SAMPLE

NUMBER OF

IDENTIFICATION

PACKAGE

SIZE

FAILURES

Static Life Test (Note 1)

Ta = 135

DC Parameters

Biased

& functionality

Time = 192 hrs.

Moisture Testing (Note 2)

Pressure Pot

Ta = 121

DC Parameters

P = 15 psi.

& functionality

RH= 100%

Time = 168hrs.

85/85

Ta = 85

DC Parameters

RH = 85%

& functionality

Biased

Time = 1000hrs.

Mechanical Stress (Note 2)

Temperature

-65

C/150

DC Parameters

Cycle

1000 Cycles

Method 1010

Note 1: Life Test Data may represent plastic DIP qualification lots.
Note 2: Generic Package/Process data

Part Number MAX1952