JANTX2N4957 - Defense Supply Center Columbus

MIL-PRF-19500/426D

28 December 2001

SUPERSEDING

MIL-PRF-19500/426C

2 November 2000

PERFORMANCE SPECIFICATION

SEMICONDUCTOR DEVICE, TRANSISTOR, PNP, SILICON, AMPLIFIER

TYPE 2N4957 AND 2N4957UB

JAN, JANTX, JANTXV, AND JANS

This specification is approved for use by all Departments

and Agencies of the Department of Defense.

1. SCOPE

1.1 Scope. This specification covers the performance requirements for PNP silicon, VHF-UHF amplifier

transistors. Four levels of product assurance are provided for each device type as specified in MIL-PRF-19500.

1.2 Physical dimensions. See figure 1 (T0-72) and figure 2 (surface mount).

1.3 Maximum ratings.

PT (1)

TA = +25°C

VCEO

VCBO IC VEBO

TSTG and TJ

mW

V dc

mA dc

V dc

°C

200

30

3.0

-65 to +200

(1) Derate at 1.14 mW/°C above TA > +25°C.

* 1.4 Primary electrical characteristics (common to all types).

Limits

hFE3

|hfe|

rb'Cc

Ccb

Gpe

NF

VCE = 10

V dc

IC = 5.0

mA dc

IE = 2.0 mA

dc

VCE = 10 V

dc

f = 100 MHz

IE = 2.0 mA dc

f = 63.6 MHz

VCB = 10 V dc

(2N4957 only )

IE = 2.0 mA dc

f = 63.6 MHz

VCB = 10 V dc

(2N4957UB

only)

VCB = 10 V dc

IE = 0

100 kHz ≤ f ≤ 1

MHz

IC = 2.0 mA dc

f = 450 MHz

VCE = 10 V dc

IC = 2.0 mA dc

VCE = 10 V dc

f = 450 MHz

ps ps

pF

dB

Min 30 12 1.0 1.0 17

Max 165 36 8.0 16.0 0.8 25 3.5

Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in

improving this document should be addressed to: Defense Supply Center Columbus, ATTN: DSCC-VAC, P. O. Box

3990 East Broad Street, Columbus, OH 43216-5000, by using the Standardization Document Improvement

Proposal (DD Form 1426) appearing at the end of this document or by letter.

AMSC N/A FSC 5961

DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.

INCH-POUND The documentation and process

conversion measures necessary to

comply with this revision shall be

completed by 28 March 2002.

MIL-PRF-19500/426D

2

* FIGURE 1. Physical dimensions of transistor type 2N4957.

MIL-PRF-19500/426D

3

Symbol

Dimensions

Notes

Inches

Millimeters

Min

Max

Min

Max

CD

0.178

0.195

4.52

4.95

5

CH

0.170

0.210

4.32

5.33

HD

0.209

0.230

5.31

5.84

5

LC

.100 TP 2.54 TP

LD

0.016

0.021

0.406

0.533

7,8

LL

0.500

0.750

12.70

19.05

7,8

LU

0.016

0.019

0.41

0.48

7,8

L1

0.050

1 .27

8

L2

0.250

6.35

8

P

0.100

2.54

Q

0.050

1.27

5

r

.007

0.18

TL

0.028

0.048

0.71

1.22

TW

0.036

0.046

0.91

1.17

α

45° T. P.

NOTES:

1. Dimension are in inches.

2. Metric equivalents are given for general information only.

3. Beyond r (radius) maximum, TH shall be held for a minimum length of .011 (0.28 mm).

4. Dimension TL measured from maximum HD.

5. Body contour optional within zone defined by HD, CD, and Q.

6. Leads at gauge plane .054 +.001 -.000 inch (1.37 +0.03 -0.00 mm) below seating plane shall be within .007

inch (0.18 mm) radius of true position (TP) at maximum material condition (MMC) relative to tab at MMC.

The device may be measured by direct methods.

7. Dimension LU applies between L1 and L2. Dimension LD applies between L2 and LL minimum. Diameter is

uncontrolled in L1 and beyond LL minimum.

8. All four leads.

9. Dimension r (radius) applies to both inside corners of tab.

10. In accordance with ANSI Y14.5M, diameters are equivalent to φx symbology.

11. Lead 1 = emitter, lead 2 = base, lead 3 = collector, lead 4 = case (electrically connected).

* FIGURE 1. Physical dimensions of transistor type 2N4957 Continued.

MIL-PRF-19500/426D

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Dimensions

Symbol Inches Millimeters Note

Min Max Min Max

A .046 .056 0.97 1.42

A1 .017 .035 0.43 0.89

B1 .016 .024 0.41 0.61

B2 .016 .024 0.41 0.61

B3 .016 .024 0.41 0.61

D .085 .108 2.41 2.74

D1 .071 .079 1.81 2.01

D2 .035 .039 0.89 0.99

D3 .085 .108 2.41 2.74

E .115 .128 2.82 3.25

E3 .128 3.25

L1 .022 .038 0.56 0.96

L2 .022 .038 0.56 0.96

NOTES:

1. Dimensions are in inches.

2. Metric equivalents are given for general information only.

FIGURE 2. Physical dimensions, surface mount (2N4957UB version).

MIL-PRF-19500/426D

5

2. APPLICABLE DOCUMENTS

2.1 General. The documents listed in this section are specified in sections 3 and 4 of this specification. This

section does not include documents cited in other sections of this specification or recommended for additional

information or as examples. W hile every effort has been made to ensure the completeness of this list, document

users are cautioned that they must meet all specified requirements documents cited in sections 3 and 4 of this

specification, whether or not they are listed.

2.2 Government documents.

2.2.1 Specifications, standards, and handbooks. The following specifications, standards, and handbooks form a

part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are

those listed in the issue of the Department of Defense Index of Specifications and Standards (DoDISS) and

supplement thereto, cited in the solicitation (see 6.2).

SPECIFICATION

DEPARTMENT OF DEFENSE

MIL-PRF-19500 - Semiconductor Devices, General Specification for.

STANDARD

DEPARTMENT OF DEFENSE

MIL-STD-750 - Test Methods for Semiconductor Devices.

(Unless otherwise indicated, copies of the above specifications, standards, and handbooks are available from the

Document Automation and Production Services (DAPS), Building 4D (DPM-DODSSP), 700 Robbins Avenue,

Philadelphia, PA 19111-5094.)

2.2 Order of precedence. In the event of a conflict between the text of this document and the references cited

herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws

and regulations unless a specific exemption has been obtained.

3. REQUIREMENTS

3.1 General. The requirements for acquiring the product described herein shall consist of this document and

MIL-PRF-19500.

3.2 Qualification. Devices furnished under this specification shall be products that are manufactured by a

manufacturer authorized by the qualifying activity for listing on the applicable qualified manufacturer's list (QML)

before contract award (see 4.2 and 6.3).

3.3 Abbreviations, symbols, and definitions. Abbreviations, symbols, and definitions used herein shall be as

specified in MIL-PRF-19500.

3.4 Interface and physical dimensions. The interface and physical dimensions shall be as specified in

MIL-PRF-19500, and figure 1 (T0-72 ) and 2 (UB, surface mount).

3.4.1 Lead finish. Unless otherwise specified, lead finish shall be solderable in accordance with MIL-STD-750,

MIL-PRF-19500, and herein. Where a choice of lead finish is desired, it shall be specified in the acquisition

document (see 6.2).

* 3.5 Marking. Devices shall be marked in accordance with MIL-PRF-19500, except for the UB suffix package.

Marking on the UB package shall consist of an abbreviated part number, the date code, and the manufacturer's

symbol or logo. The prefixes JAN, JANTX, JANTXV, and JANS can be abbreviated as J, JX, JV, and JS

respectively. The "2N" prefix and the "UB" suffix can also be omitted.

MIL-PRF-19500/426D

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3.6 Electrical performance characteristics. Unless otherwise specified herein, the electrical performance

characteristics are as specified in 1.3, 1.4, and table I.

3.7 Electrical test requirements. The electrical test requirements shall be the subgroups specified in table I, group

A herein.

3.8 Workmanship. Semiconductor devices shall be processed in such a manner as to be uniform in quality and

shall be free from other defects that will affect life, serviceability, or appearance.

4. VERIFICATION

4.1 Classification of inspections. The inspection requirements specified herein are classified as follows:

a. Qualification inspection (see 4.2).

b. Screening (see 4.3)

c. Conformance inspection (see 4.4).

4.2 Qualification inspection. Qualification inspection shall be in accordance with MIL-PRF-19500 and as specified

herein.

* 4.3 Screening (JANTX, JANTXV and JANS levels only). Screening shall be in accordance with table IV of

MIL-PRF-19500 and as specified herein. The following measurements shall be made in accordance with table I

herein. Devices that exceed the limits of table I herein shall not be acceptable.

Screen (see table IV

of MIL-PRF-19500)

Measurement

JANS level

JANTX and JANTXV levels

3c

Thermal impedance, method 3131

of MIL-STD-750

Thermal impedance, method 3131 of

MIL-STD-750

7

Hermetic seal (optional)

(1)

9

ICBO1, hFE3

Not applicable

10

24 hours minimum

11

ICBO1; hFE3; ∆ICBO1 = 100 percent

of initial value or10 nA dc,

whichever is greater.

∆hFE3 = ±20 percent

ICBO1 ,hFE3

12

See 4.3.1, 240 hours minimum

See 4.3.1, 80 hours minimum

13

Subgroups 2 and 3 of table I

herein; ∆ICBO1= 100 percent of

initial value or 10 nA dc,

whichever is greater;

∆hFE3 = ±20 percent

Subgroup 2 of table I herein;

∆ICBO1= 100 percent of initial value or

10 nA dc, whichever is greater;

∆hFE3 = ±20 percent

(1) Hermetic seal test shall be performed in either screen 7 or screen 14.

MIL-PRF-19500/426D

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4.3.1 Power burn-in. Power burn-in conditions are as follows: TA = Room ambient as defined in the general

requirements of 4.5 of MIL-STD-750, VCB = 10 - 20 V dc. A power dissipation PD = 100 percent of PT maximum as

defined in 1.3 shall be used.

4.4 Conformance inspection. Conformance inspection shall be in accordance with MIL-PRF-19500, and as

specified herein. If alternate screening is being performed in accordance with appendix E, "Alternate procedure for

screening of JANTX and JANTXV types", of MIL-PRF-19500, a sample of screened devices shall be submitted to

and pass the requirements of group A1 and A2 inspection only (table VIb, group B, subgroup 1 is not required to be

performed again if group B has already been satisfied in accordance with 4.4.2).

4.4.1 Group A inspection. Group A inspection shall be conducted in accordance with MIL-PRF-19500, and table I

herein.

4.4.2 Group B inspection. Group B inspection shall be conducted in accordance with the tests and conditions

specified for subgroup testing in table VIa (JANS) of MIL-PRF-19500 and 4.4.2.1 herein. (See 4.4.2.2 for JAN,

JANTX, and JANTXV group B testing.) Electrical measurements (end-points) and delta requirements shall be in

accordance with table II herein as specified in the footnotes for table II.

* 4.4.2.1 Group B inspection, table VIa (JANS) of MIL-PRF-19500.

Subgroup Method Condition

B4 1037 VCB = 10 V dc.

B5 1027 VCB = 10 - 20 V dc minimum PD = maximum rated PT (see 1.3),

T

J = +150°C minimum, t = 1000 hours minimum.

4.4.2.2 Group B inspection, (JAN, JANTX, and JANTXV). Separate samples may be used for each step. For

rules on resubmission for failed steps, see MIL-PRF-19500 rules on resubmission of failed subgroups.

Step Method Condition

1. 1039 Steady-state life: Test condition B, 340 hours, VCB = 10 - 20 V dc. n = 45

devices, c = 0. Maximum rated power as defined in 1.3 shall be applied to

the device to achieve a TJ = 150°C minimum.

2. 1039 Steady-state life test of step 1 shall be extended to 1,000 hours for each die

design. Samples shall be selected from a wafer lot every twelve months of

wafer production. Group B step 2 shall not be required more than once for

any single wafer lot. n = 45 devices, c = 0

3. 1032 High-temperature life (non-operating), TA = +200°C n = 22, c = 0

4.4.2.3 Group B sample selection. Samples selected from group B inspection shall meet all of the following

requirements:

a. For JAN, JANTX and JANTXV samples shall be selected randomly from a minimum of three wafers (or

from each wafer in the lot) from each wafer lot. For JANS, samples shall be selected from each inspection

lot. See MIL-PRF-19500.

b. Must be chosen from an inspection lot that has been submitted to and passed group A, subgroup 2

conformance inspection. When the final lead finish is solder or any plating prone to oxidation at high

temperature, the samples for life test (subgroups B4 and B5 for JANS, and group B for JAN, JANTX and

JANTXV) may be pulled prior to the application of final lead finish.

MIL-PRF-19500/426D

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4.4.3 Group C inspection, JANS. Group C inspection shall be conducted in accordance with the tests and

conditions specified for subgroup testing in table VII of MIL-PRF-19500, and 4.4.3.1 herein (JANS). See 4.4.3.2 for

JAN, JANTX, and JANTXV group C testing. Electrical measurements (end points) and delta requirements shall be in

accordance with the steps of table II herein and as specified in the notes for table II.

4.4.3.1 Group C inspection, table VII (JANS) of MIL-PRF-19500.

Subgroup Method Condition

C2 2036 Test condition E; not applicable for UB devices.

C6 1026 VCB = 10 - 20 V dc; PT = maximum rated power as defined in 1.3. Adjust TA

to achieve TJ = +150°C minimum.

4.4.3.2 Group C inspection, JAN, JANTX, and JANTXV. Group C inspection (JAN, JANTX, and JANTXV), see

table VII of MIL-PRF-19500.

Subgroup Method Condition

C2 2036 Condition E; not applicable to UB devices.

C6 Not applicable.

4.4.3.3 Group C sample selection. Samples for subgroups in group C shall be chosen at random from any

inspection lot containing the intended package type and lead finish procured to the same specification which is

submitted to and passes group A tests for conformance inspection. When the final lead finish is solder or any

plating prone to oxidation at high temperature, the samples for C6 life test may be pulled prior to the application of

final lead finish. Testing of a subgroup using a single device type enclosed in the intended package type shall be

considered as complying with the requirements for that subgroup.

* 4.4.4 Group E inspection. Group E inspection shall be performed in accordance with table III herein for

qualification or re-qualification only. In case qualification was awarded to a prior revision of the specification sheet

that did not request the performance of table III tests, the tests specified in table III herein must be performed to

maintain qualification.

4.5 Methods of inspection. Methods of inspection shall be as specified in the appropriate tables and as follows.

4.5.1 Pulse measurements. Conditions for pulse measurement shall be as specified in section 4 of MIL-STD-750.

4.5.2 Collector -base time constant. This parameter may be determined by applying an RF signal voltage of 1 volt

(rms) across the collector-base terminals, and measuring the ac voltage drop (Veb) with a high impedance rf

voltmeter across the emitter-base terminals. With f = 63.6 MHz used for the 1 volt signal, the following computation

applies: Cc (ps) = 2 x Veb (millivolts).

MIL-PRF-19500/426D

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TABLE I. Group A inspection.

Inspection 1/

MIL-STD-750

Symbol

Limit

Unit

Method

Conditions

Min

Max

Subgroup 1 2/

Visual and mechanical

Inspection 3/

2071

n = 45 devices, c = 0

Solderability 3/ 4/ 2026

15 leads, c = 0

Resistance to solvents

3/ 4/ 5/

1022

15 devices, c = 0

Temperature cycling

3/ 4/

1051

Test condition C, 25 cycles.

n = 22 devices, c = 0

Heremetic seal 4/

Fine leak

Gross leak

1071

n = 22 devices, c = 0

Electrical

measurements 4/

Group A, subgroup 2

Bond strength 3/ 4/ 2037

Precondition TA = +250°C

at t = 24 hrs or TA = +300°C

at t = 2 hrs. n = 11 wires, c = 0

Subgroup 2

Breakdown voltage,

collector to emitter

3011

Bias condition D; IC = 1.0 mA dc,

IB = 0

V(BR)CEO

30

V dc

Collector to base cutoff

current

3036

Bias condition D; VCB = 30 Vdc

ICB02

100

µA dc

Emitter to base cutoff

current

3061

Bias condition D; VEB = 3 Vdc

IEB02

100

µA dc

Collector to base cutoff

current

3036

Bias condition D; VCB = 20 V dc,

IE = 0

ICB01

100

nA dc

Forward-current

transfer ratio*

3076

VCE = 10 V dc; IC = 0.5 mA dc;

hFE1

15

Forward-current

transfer ratio*

3076

VCE = 10 V dc; IC = 2.0 mA dc;

hFE2

20

Forward-current

transfer ratio*

3076

VCE = 10 V dc; IC = 5.0 mA dc;

hFE3 30 165

See footnotes at end of table.

MIL-PRF-19500/426D

10

* TABLE I. Group A inspection - Continued.

Inspection 1/

MIL-STD-750

Symbol

Limit

Unit

Method

Conditions

Min

Max

Subgroup 3

High temperature

operation:

TC = +150°C

Collector to base cutoff

current

3036

Bias condition D; VCE = 20 V dc,

IE = 0

ICB02

100

µA dc

Low temperature operation:

TA = -55°C

Forward-current t ransfer

ratio

3076

VCE = 10 V dc; IC = 5 mA dc;

hFE4 10

Subgroup 4

Magnitude of common-

emitter small-signal short-

circuit forward-current

transfer ratio

3306

VCE = 10 V dc; IE = 2. 0 mA dc;

f = 100 MHz; case lead grounded

|hfe|

12

36

Collector to base feedback

capacitance

3236

VCB = 10 V dc; IE = 0;

100 kHz ≤ f ≤ 1 MHz; case and

emitter leads shall be guarded

Ccb

0.8

pF

Collector to base time

constant

(2N4957 only )

3236 VCB = 10 V dc; IE = 2.0 mA dc;

f = 63.6 MHz; case and emitter leads

shall be grounded (see 4.5.2 and

figure 3)

rb'Cc 1.0 8.0 ps

Collector to base time

constant

(2N4957UB only )

3236 VCB = 10 V dc; IE = 2.0 mA dc;

f = 63.6 MHz; case and emitter leads

shall be grounded (see 4.5.2 and

figure 3)

rb'Cc 1.0 16.0 ps

Noise figure 3246

VCE = 10 V dc; IC = 2. 0 mA dc;

f = 450 MHz; RL = 50 Ω; case lead

shall be grounded (see figure 4)

NF

3.5

dB

Common-emitter small

signal power gain

3256

VCE = 10 V dc; C = 2.0 mA dc;

f = 450 MHz; case lead shall be

grounded (see figure 4)

GPE

17

25

dB

Subgroups 5, 6, and 7

Not applicable

1/ For sampling plan (unless otherwise specified), see MIL-PRF-19500.

2/ For resubmission of failed subgroup A1, double the sample size of the failed test or sequence of tests. A failure

in group A, subgroup 1 shall not require retest of the entire subgroup. Only the failed test shall be rerun upon

submission.

3/ Separate samples may be used.

4/ Not required for JANS devices.

5/ Not required for laser marked devices.

MIL-PRF-19500/426D

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TABLE II. Groups B and C electrical end-point inspection measurements. 1/ 2/ 3/ 4/

Step

Inspection

MIL-STD-750

Symbol

Limits

Unit

Method

Conditions

Min

Max

1.

Collector to base

cutoff current

3036

Bias condition D;

VCB = 20 V dc, IE = 0

ICB01

100

nA dc

2.

Collector to base

cutoff current

3036

Bias condition D;

VCB = 20 V dc, IE = 0

∆ICB01

±100 percent of initial

value or 10 nA dc,

whichever is greater.

3.

Forward current

transfer ratio

3076

IC = 5 mA dc,

VCE = 10 V dc

hFE3 30

165

4.

Forward current

transfer ratio

3076

IC = 5 mA dc,

VCE = 10 V dc

∆hFE3 30

±20 percent change

from initial reading.

1/ The electrical measurements for table VIa (JANS) of MIL-PRF-19500 are as follows:

a. Subgroup 3, see table II herein, steps 1 and 3.

b. Subgroup 4 and 5, see table II herein, steps 1, 2, 3, and 4.

2/ The electrical measurements for group B of 4.4.2.2 herein (JAN, JANTX, and JANTXV) are as follows:

a. Steps 1, 2, and 3, of 4.4.2.2, see table II herein, all steps.

3/ The electrical measurements for table VII (JANS) of MIL-PRF-19500 are as follows:

a. Subgroup 2, see table II herein, steps 1 and 3.

b. Subgroups 6, see table II herein, steps 1, 2, 3 and 4.

4/ The electrical measurements for group C, 4.4.3.2 herein (JAN, JANTX, and JANTXV) are as follows:

a. Step 2 of 4.4.3.2, see table II herein, steps 1 and 3.

MIL-PRF-19500/426D

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* TABLE III. Group E inspection (all quality levels) - for qualification only.

MIL-STD-750

Inspection

Method

Conditions

Qualification

Subgroup 1

Temperature cycling

(air to air)

Hermetic seal

Fine leak

Gross leak

Electrical measurements

Subgroup 2

Intermittent life

Electrical measurements

Subgroups 3, 4, 5, 6, and 7

Not applicable

1051

1071

1037

Test condition C, 500 cycles

See group A, subgroup 2 and table II herein.

VCB = 10 V dc, 6000 cycles

See group A, subgroup 2 and table II herein.

45 devices

c = 0

45 devices

c = 0

Subgroup 8

45 devices

c = 0

Reverse stability 1033 Condition A for devices ≥ 400 V, condition B for

devices < 400 V.

MIL-PRF-19500/426D

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FIGURE 3. RF amplifier for collector to base time constant tests.

MIL-PRF-19500/426D

14

Values:

C1, C7 = 1-10 pF (Variable air-piston type capacitors)

C2, C4, C6 = 500 pF (button type capacitors)

C3, C8 = .4 - 6.0 pF (Variable air-piston type capacitors)

C5 = 1,000 pF

R1 = 2.7 kΩ

R2, R4 = 1 kΩ

R3 = 20 kΩ

L1 = silver-plated brass bar, 1.0 inch long by 0.25 inch o.d. (straight bar)

L2 = silver-plated brass bar, 1.5 inches long by 0.25 inch o.d. Tap is 0.25 inch from collector (straight bar).

L3 = 1/2 turn of AWG number 16 wire, loop o.d. approximately 0.5 inch, located 0.25 inch from, and parallel to L2.

L4 = 0.22 µH

The noise source is a hot-cold body, (AIL type 70 or equivalent) with a test receiver (AIL type 70 or equivalent).

FIGURE 4. RF amplifier for power gain and noise figure tests.

MIL-PRF-19500/426D

15

5. PACKAGING

5.1 Packaging. For acquisition purposes, the packaging requirements shall be as specified in the contract or

order (see 6.2). When actual packaging of materiel is to be performed by DoD personnel, these personnel need to

contact the responsible packaging activity to ascertain requisite packaging requirements. Packaging requirements

are maintained by the Inventory Control Point's packaging activity within the Military Department or Defense Agency,

or within the Military Department's System Command. Packaging data retrieval is available from the managing

Military Department's or Defense Agency's automated packaging files, CD-ROM products, or by contacting the

responsible packaging activity.

6. NOTES

(This section contains information of a general or explanatory nature that may be helpful, but is not mandatory.)

6.1 Intended use. The notes specified in MIL-PRF-19500 are applicable to this specification.

6.2 Acquisition requirements. Acquisition documents must specify the following:

a. Title, number, and date of this specification.

b. Issue of DoDISS to be cited in the solicitation, and if required, the specific issue of individual

documents referenced (see 2.2).

c. Packaging requirements (see 5.1).

d. Lead finish (see 3.4.1).

6.3 Qualification. With respect to products requiring qualification, awards will be made only for products which

are, at the time of award of contract, qualified for inclusion in Qualified Manufacturers' List (QML) whether or not

such products have actually been so listed by that date. The attention of the contractors is called to these

requirements, and manufacturers are urged to arrange to have the products that they propose to offer to the Federal

Government tested for qualification in order that they may be eligible to be awarded contracts or orders for the

products covered by this specification. Information pertaining to qualification of products may be obtained from

Defense Supply Center, Columbus, ATTN: DSCC-VQE, P.O. Box 3990, Columbus, OH 43216-5000.

* 6.4 Changes from previous issue. The margins of this specification are marked with asterisks to indicate where

changes from the previous issue were made. This was done as a convenience only and the Government assumes

no liability whatsoever for any inaccuracies in these notations. Bidders and contractors are cautioned to evaluate the

requirements of this document based on the entire content irrespective of the marginal notations and relationship to

the last previous issue.

Custodians: Preparing activity:

Army - CR DLA - CC

Navy - EC

Air Force - 11 (Project 5961-2576)

DLA - CC

Review activities:

Army - AR, MI

Navy - SH

Air Force - 19

STANDARDIZATION DOCUMENT IMPROVEMENT PROPOSAL

INSTRUCTIONS

1. The preparing activity must complete blocks 1, 2, 3, and 8. In block 1, both the document number and revision

letter should be given.

2. The submitter of this form must complete blocks 4, 5, 6, and 7.

3. The preparing activity must provide a reply within 30 days from receipt of the form.

NOTE: This form may not be used to request copies of documents, nor to request waivers, or clarification of requirements on

current contracts. Comments submitted on this form do not constitute or imply authorization to waive any portion of the referenced

document(s) or to amend contractual requirements.

I RECOMMEND A CHANGE: 1. DOCUMENT NUMBER

MIL-PRF-19500/426D 2. DOCUMENT DATE

28 December 2001

3. DOCUMENT TITLE

SEMICONDUCTOR DEVICE, TRANSISTOR, PNP, SILICON, AMPLIFIER TYPE 2N4957 AND 2N4957UB JAN, JANTX, JANTXV,

AND JANS

4. NATURE OF CHANGE (Identify paragraph number and include proposed rewrite, if possible. Attach extra sheets as needed.)

5. REASON FOR RECOMMENDATION

6. SUBMITTER

a. NAME (Last, First, Middle initial)

b. ORGANIZATION

c. ADDRESS (Include Zip Code) d. TELEPHONE (Include Area Code)

COMMERCIAL

DSN

FAX

EMAIL

7. DATE SUBMITTED

8. PREPARING ACTIVITY

a. Point of Contact

Alan Barone

b. TELEPHONE

Commercial DSN FAX EMAIL

614-692-0510 850-0510 614-692-6939 alan.barone@dscc.dla.mil

c. ADDRESS

Defense Supply Center, Columbus

ATTN: DSCC-VAC

P.O. Box 3990

Columbus, OH 43216-5000

IF YOU DO NOT RECEIVE A REPLY WITHIN 45 DAYS, CONTACT:

Defense Standardization Program Office (DLSC-LM)

8725 John J. Kingman, Suite 2533

Fort Belvoir, VA 22060-6221

Telephone (703) 767-6888 DSN 427-6888

DD Form 1426, Feb 1999 (EG) Previous editions are obsolete WHS/DIOR, Feb 99