1、EIA SPECIFICATION Specification for Small Form Factor 63.5 millimeters (2.5 inches) Disk DrivesEIA-720-B (Revision of EIA-720-A) August 2016Electronic Components Industry Association ANSI/EIA-720-B-2016 Approved: August 25, 2016 EIA-720-BNOTICE EIA Engineering Specifications and Publications are des
2、igned to serve the public interest through eliminating misunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for his particular need. Existence
3、of such Specifications and Publications shall not in any respect preclude any member or nonmember of ECIA from manufacturing or selling products not conforming to such Specifications and Publications, nor shall the existence of such Specifications and Publications preclude their voluntary use by tho
4、se other than ECIA members, whether the standard is to be used either domestically or internationally. Specifications and Publications are adopted by ECIA in accordance with the American National Standards Institute (ANSI) patent policy. By such action, ECIA does not assume any liability to any pate
5、nt owner, nor does it assume any obligation whatever to parties adopting the Specification or Publication. This EIA specification is considered to have International Standardization implications, but the International Electrotechnical Commission activity has not progressed to the point where a valid
6、 comparison between the EIA standard and the IEC document can be made. This Specification does not purport to address all safety problems associated with its use or all applicable regulatory requirements. It is the responsibility of the user of this Specification to establish appropriate safety and
7、health practices and to determine the applicability of regulatory limitations before its use. NOTE The users attention is called to the possibility that compliance with this standard may require use of an invention covered by patent rights. By publication of this standard, no position is taken with
8、respect to the validity of any such claim(s) or of any patent rights in connection therewith. If a patent holder has filed a statement of willingness to grant a license under these rights on reasonable and nondiscriminatory terms and conditions to applicants desiring to obtain such a license, then d
9、etails may be obtained from the standards developer Neither the standards developer nor ANSI is responsible for identifying patents for which a license may be required by an American National Standard or for conducting inquiries into the legal validity or scope of those patents that are brought to t
10、heir attention. (From Standards Proposal No. 5343-A, formulated under the cognizance of the CE-2.0 Committee on EIA National Connector and Socket Standards.) Published by Electronic Components Industry Association 2016 EIA Standards & Technology Department 2214 Rock Hill Road, Suite 265 Herndon, VA
11、20170 PLEASE ! DONT VIOLATE THE LAW!This document is copyrighted by the ECIA and may not be reproduced without permission. Organizations may obtain permission to reproduce a limited number of copies through entering into a license agreement. For information, contact: IHS Markit 15 Inverness Way East
12、 Englewood, CO 80112-5704 or call USA and Canada (1-877-413-5186), International (303-397-7956) (This page left blank) i CONTENTS Clause Page Foreword . iii 1 Introduction . 1 1.1 Scope . 1 1.2 Applicable documents . 1 2 General 2 2.1 Application environment . 2 2.2 Patent rights and conformance 2 2
13、.3 Definitions . 2 3 Interface requirements 3 3.1 Power and grounding 3 3.2 I/O signals connectors . 3 4 Physical configurations . 3 4.1 Physical dimensions 3 4.2 Generic drive dimensional information 4 4.3 Drive connectors . 9 4.4 Drive considerations . 10 4.5 Drive with 50-pin connector . 10 4.6 D
14、rive with SCA-2 (Single Connector Attached) connector . 13 4.7 Drive with serial attached connector . 16 4.8 Drive with combination connector including USB Micro-B receptacle . 19 4.9 Drive with 0.8millimeter card edge drive connector . 22 ii CONTENTS (continued) Figure Page 1 Generic form factor .
15、6 2 Detail views of form factor . 7 3 Required mounting holes 8 4 Length of drive with connector . 9 5 50 - pin connector location . 12 6 SCA-2 connector referenced to bottom mounting screw 14 7 SCA-2 connector referenced to side mounting screw . 15 8 Serial attached connector referenced to bottom m
16、ounting screw . 17 9 Serial attached connector referenced to side mounting screw 18 10 Combination connector including a USB 3.0 Micro-B receptacle referenced to bottom mounting screw 20 11 Combination connector including a USB 3.0 Micro-B receptacle referenced to side mounting screw . 21 12 0.8 mil
17、limeter card edge drive connector location 23 Table 1 Generic form factor dimensions 4 2 50-pin connector location . 11 3 SCA-2 connector location . 13 4 Serial attached connector location 16 5 USB 3.0 combination connector location . 19 6 0.8 millimeter card edge drive connector location . 22 Annex
18、 A Related documents (informative) . A-1 A.1 EIA specification A-1 A.2 Industry documents . A-1 iii ForewordThis Specification is from EIA Standards Proposal No. 5343, formulated under the cognizance of EIA CE-2.0, Committee on Connector and Socket Standards. This project was conducted in liaison wi
19、th the SFF Committee as representing the disk drive industry. Utilization of this Standard is intended to eliminate misunderstandings or confusion between a manufacturer and user with respect to product performance and testing requirements for this as well as other possible applications. The develop
20、ment work on this specification was done by the SFF Committee, an industry group. The membership of the committee since its formation in August 1990 has included a mix of companies that are leaders across the industry. iv (This page left blank) EIA-720-B Page 1 Specification for Small Form Factor 63
21、.5 millimeters (2.5 inches) Disk Drives (From EIA Standards Proposal No. 5343-A, formulated under the cognizance of the EIA CE-2.0 Committee on National Connector and Socket Standards, and previously published in EIA-720-A.) 1. Introduction 1.1 Scope This specification defines the dimensions and con
22、nector locations of 63.5 millimeters (2.5 inches) small form factor disk drives. The purpose of this specification is to define the external characteristics of small form factor disk drives so that products from different vendors may be used in the same mounting configurations. This specification es
23、tablishes the requirements for external dimensions, connectors, connector placement, and mounting holes to assist manufacturers in the systems integration of small form factor disk drives. 1.2 Applicable documents The following documents form a part of this specification to the extent indicated here
24、in. In the event of conflict between this specification and the referenced documents, this specification shall take precedence. 1.2.1 EIA specification EIA-700A0AE Detail Specification for Trapezoidal Connectors with Nonremovable Ribbon Cable Contacts on 1.27 mm Pitch Double Row Used with Single Con
25、nector Attachments (SCA2)1.2.2 Industry document ASME Y14.5 Dimensioning and Tolerancing SFF-8201 Specification for 2.5 inch Form Factor Drive Dimensions SFF-8212 Specification for 2.5 inch Form Factor Drive with 50-pin Connector EIA-720-B Page 2 1.2.3 SFF specifications SFF-8222 Specification for 2
26、.5 inch Form Factor Drive with SCA-2 Connector SFF-8223 Specification for 2.5 inch Form Factor Drive with Serial Attached Connector SFF-8248 Specification for 2.5inch Form Factor w/Combo Connector including USB Micro-B Receptacle SFF-8252 Specification for 2.5 inch Form Factor Drive with SFF-8784 Co
27、nnector 2 General 2.1 Application environment The application environment for small form factor disks is any computer, cabinet, or enclosure connecting to one or more drives in a restricted packaging environment. The purpose of this specification is to provide information that will assist vendors to
28、 design products that can fit the same packaging envelope. Small form factor disks are widely used where low power and small size are important configuration parameters. 2.2 Patent rights and conformance The users attention is called to the possibility that compliance with this standard may require
29、use of an invention covered by patent rights. (See NOTE under NOTICE inside the front cover regarding patent disclosure requirements.) 2.3 Definitions 2.3.1 Optional This term describes features that are not required by the specification. However, if any feature defined by the specification is imple
30、mented, it shall be done in the same way as defined by the specification. Describing a feature as optional in the text is done to assist the reader. 2.3.2 Vendor specific This term is used to describe bits, bytes, fields, pins, signals, code values and features that are not described in this specifi
31、cation and may be used in a way that varies between vendors. EIA-720-B Page 3 3 Interface requirements 3.1 Power and grounding 3.1.1 Power The drive receives DC power through the same connector that contains the signal lines if it is a direct mount to a receptacle on a board. Certain supported Inter
32、face Standards require DC power to be delivered through the same connector that contains the signal lines. 3.1.2 Grounding Provision for tying the DC logic ground and the chassis ground together or for separating these two grounds is vendor specific. 3.2 I/O signals connectors 3.2.1 The I/O signals
33、connectors are suited to different applications. The defined configurations are: A 50-pin low density connector for Parallel ATA and Parallel SCSI An SCA-2 connector for Parallel SCSI An SCA-2 connector for Fibre Channel Arbitrated Loop A unitized connector for Serial Attached SCSI A unitized connec
34、tor for Serial ATA A combination connector including a USB Micro-B receptacle A unitized 0.8mm Card Edge Drive Connector for serial applications 3.2.2 See the respective industry interface standard for pin assignments and application information. 4 Physical configurations This content is based on SF
35、F-8201 (63.5 millimeters (2.5 inches) drive form factor dimensions). 4.1 Physical dimensions 4.1.1 Any physical measurements shall be performed at 20 C 2 C. The drive shall not be exposed to any conditions (transit temperatures, shock, etc.) beyond the manufacturers specified limits before measureme
36、nt. 4.1.2 The dimensioning conventions are described in ASME Y14.5. Dimensions are supplied in both millimeters and inches. Unless stated otherwise, millimeters are the controlling dimensional units. EIA-720-B Page 4 4.2 Generic drive dimensional information 4.2.1 Table 1 specifies the drive dimensi
37、ons and correlates them to the figures. Dimensions identified as obsolete are for reference and may apply to existing device features. New devices are to be designed to dimensions that are not identified as obsolete. 4.2.2 Figure 1 defines the dimensions and shows relationships among the dimensions.
38、 4.2.3 Figure 2 contains detail views of the form factor. 4.2.4 Figure 3 defines the required mounting holes. 4.2.5 Figure 4 defines the length of the form factor plus connector. Table 1 - Generic form factor dimensions Dimension Tolerance Millimeters Inches Comments A 1 19.05 0.750 A 1 17.00 0.669
39、A 1 15.00 0.591 A 1 12.70 0.500 A 1 10.50 0.413 A 1 9.50 0.374 A2=A3=0.20 millimeter A 1 8.47 0.333 A 1 7.00 0.276 A2=0.20 millimeter A 1 5.00 0.197 A2=A3=0.20 millimeter A 2 0.00 0.000 A 3 0.50 0.020 A 4 69.85 2.750 A 5 0.25 0.010 A 6 Max 101.85 4.010 Obsolete A 6 Max 100.45 3.955 New requirement A
40、10 100.20 3.945 Clause 4.5 A11 100.50 3.957 Clause 4.7 A12 110.20 4.339 Clause 4.6 A23 3.00 0.118 A24 34.93 1.375 Obsolete A25 38.10 1.500 Obsolete A26 M3 N/A A27 0.50 0.020 EIA-720-B Page 5 Table 1 - Generic form factor dimensions (continued) Dimension Tolerance Millimeters Inches Comments A28 4.07
41、 0.160 A29 61.72 2.430 A30 34.93 1.375 Obsolete A31 38.10 1.500 Obsolete A33 0.50 0.020 A37 8.00 0.315 A50 14.00 0.551 A51 90.60 3.567 A52 14.00 0.551 A53 90.60 3.567 Threads A32 Size M3 A38 Min Penetration 3 2 for A1 7 millimeters A41 Min Penetration 2.5 NOTES 1 (A4+A5) represents the maximum width
42、 of the drive, 70.10 millimeters. 2 Dimensions A10, A11, and A12 are based on a nominal form factor length of 100.20 millimeters. 3 Unless diameter targets indicate specific areas, dimensions for a surface apply to a single point minimum. If a surface is not flat, the dimension applies to the highes
43、t raised location on that surface. 4 Information in Comments column take precedence over the stated dimensions. EIA-720-B Page 6 NOTE Bottom mounting holes are optional on form factors with A1 7 millimeters. Figure 1 - Generic form factor EIA-720-B Page 7 NOTE Bottom mounting holes are optional on f
44、orm factors with A1 7 millimeters. Figure 2 - Detail views of form factor EIA-720-B Page 8 NOTE Bottom mounting holes are optional on form factors with A1 7 millimeters. Figure 3 - Required mounting holes EIA-720-B Page 9 (A10)(A11)(A12)Form factor overall length with 50-pin connectorRef. SFF-8212Fo
45、rm factor overall length with Serial ATA or Serial Attached SCSI connectorRef. SFF-8223Form factor overall length with SCA-2 connectorRef. SFF-8222ConnectorConnectorConnectorFigure 4 - Length of drive with connector 4.3 Drive connectors 4.3.1 The drive PCB and/or connector may extend beyond the HDA.
46、 If it does, there is a space at the end of the HDA underneath or above the PCB or connector overhang. Such “dead space“ is not to be encroached upon in any way by the host system. 4.3.2 There is only one location specified for the interface connector on a drive, and if a drive can be directly inser
47、ted into the backplane of a cabinet, the information necessary to assist manufacturers in systems integration is provided. 4.3.3 Backplane: Care shall be taken in the application of these drives so that excessive stress is not exerted on the connectors. Backplane configurations shall pay particular
48、attention so that the connector is not damaged due to excessive side loading, compressive forces, or from supporting the weight of the device. ef. Clause 4.5 Ref. Clause 4.7 f. Clause 4.6 EIA-720-B Page 10 4.3.4 Cabled: A connector configuration may permit the same drive to be used in either a backp
49、lane or a cabled application. Drives designed for use in cabled applications need not conform to all the dimensions and tolerances specified for backplanes e.g., if the connector was mounted in a vertical orientation it could require the PCB to be longer (thereby increasing the overall length of the drive). 4.4 Drive considerations 4.4.1 Cooling airflow Except at the attachment points, 0.75 millimeter (0.030 inch) minimum clearance around the drive is recommended for cooling airflow. 4.4.2 Mounting considerations 4.4.2.1 Th
