BQ48SH-28X6NSH

 SLUS508A – DECEMBER 2001 REVISED – JUNE 2002        FEATURES
Detachable Unit Allowing Replacement
Integrated 6-pF Watch Crystal for Real-Time



DESCRIPTION Clock Operation Integrated Lithium Coin Cell for Nonvolatile Memory Backup Protects Battery and Crystal From Conditions Associated with Surface Mount Soldering For Use With bq4802YDSH and bq4802LYDSH Keyed Insertion to Avoid Incorrect Attachment The bq48SH–28x6 is the top section suitable for any SOIC (DSH) packaged IC including the bq4802YDSH or bq4802LYDSH parallel real-time clock (RTC) and NVSRAM controller. The fully integrated SNAPHAT includes a 6-pF watch crystal and lithium coin cell with 48 mAh of capacity. The SNAPHAT is designed to be attached after the DSH packaged base SOIC has been soldered preventing the battery and crystal being over-stressed by the soldering temperatures. APPLICATIONS
Telecommunications Base Stations
Servers
Handheld Data Collection Equipment AVAILABLE OPTIONS TA PACKAGED DEVICES SNAPHAT (NSH) SYMBOL 0°C to 70°C bq48SH–28x6NSH bq48SH–28x6 † The SNAPHAT package is available taped and reeled. Add an R suffix to the device type (e.g. bq48SH–28x6NSHR to order quantities of 2,500 devices per reel. CONNECTION DIAGRAMS X2 BC X1 VSS Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. SNAPHAT is a trademark of STMicroelectronics. Copyright  2002, Texas Instruments Incorporated    !"# $ %& '# "$  (&
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 SLUS508A – DECEMBER 2001 REVISED – JUNE 2002 absolute maximum ratings over operating free-air temperature (unless otherwise noted)† Operating temperature range, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to 85°C Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C † Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. recommended operating conditions TYP UNIT Nominal battery voltage, VCC 2.8 V Nominal battery capacity 48 mAh MAX UNIT crystal specifications (DT–35 or equivalent) PARAMETER TEST CONDITIONS MIN TYP fO CL Oscillation frequency TP k Temperature turnover point Q Quality factor R1 Series resistance 45 kΩ CO Shunt capacitance 1.1 1.8 pF CO/C1 Capacitance ratio 430 600 DL Drive level ∆f/fO Aging (first year at 25C) Load capacitance 20 kHz 6 pF 25 Parabolic curvature constant 40,000 NO. C 70,000 1 1 TERMINAL NAME 30 –0.042 ppm/C TERMINAL FUNCTIONS I/O DESCRIPTION BC 3 O Battery positive terminal VSS 2 I Battery negative terminal X1 1 I Crystal input X2 4 O Crystal output 2 32.768 www.ti.com µW ppm 
 SLUS508A – DECEMBER 2001 REVISED – JUNE 2002 functional description connections The SOIC (DSH) is connected to the SNAPHAT containing the battery and crystal through four pins that insert into four press-fitted sockets in the SOIC (DSH) where the contact area is gold platted. Each of the sockets internally contains six independent contacts to ensure solid reliable connectivity and minimize contact resistance. Four molded retaining clips on the SNAPHAT also help fasten the SOIC (DSH), ensuring mechanical and electrical connection even under severe mechanical shock and vibration. The combined SOIC (DSH) and SNAPHAT assembly can sustain shock levels in excess of 100 g without separating. This package also passes variable frequency testing in accordance with MIL–STD–883, method 2007.2, condition A. Force – lbs Figure 1 illustrates the effect of repeated insertion and extraction of the SNAPHAT top to the SOIC (DSH). The force required to extract the SNAPHAT, and then to re-insert it, reduces each time. After three or four extractions, though, the reduction starts to become unnoticeable, and the force required remains at a fairly constant figure. Typically, though, the SNAPHAT needs to be extracted and re-inserted only once in its lifetime. Figure 1. SNAPHAT Insertion and Extraction Forces www.ti.com 3 
 SLUS508A – DECEMBER 2001 REVISED – JUNE 2002 functional description (continued) battery characteristics Figure 2 illustrates the lithium coin cell discharge rate for a given load. This demonstrates the characteristically flat voltage level supplied by the battery until very near the end of its life. These discharge levels have been greatly accelerated in comparison to the normal, actual usage. UL recognition The bq48SH–28x6 has been recognized by Underwriters Laboratories under their Component Recognition Program and carries UL File No. E89556. battery life The life expectancy of the battery is greatly affected by temperature and usage profiles. Figure 2 highlights the effective discharge during loading periods, but temperature during loading periods can greatly affect the effective run time as shown in Figure 3. general notes To remove the SNAPHAT top for replacement, a DIP/IC extractor tool should be used. The SNAPHAP top should be grasped by the narrow end to avoid bending the pins. CAUTION: To avoid draining the battery, do NOT place SNAPHAT pins into conductive foam. TYPICAL CHARACTERISTICS BR1225 LITHIUM COIN CELL DISCHARGE RATE vs CELL VOLTAGE 3.5 TA = 20C VCC – Cell Voltage – V 3.0 2.5 2.0 RL = 30 kΩ RL = 15 kΩ 1.5 RL = 100 kΩ 1.0 0 400 800 1200 1600 tD – Discharge Duration – h Figure 2 4 www.ti.com 2000 
 SLUS508A – DECEMBER 2001 REVISED – JUNE 2002 MECHANICAL DATA NSH (R-PDIP-P4) PLASTIC DUAL-IN-LINE D Dimension E Inches Millimeters Min. Max. Min. Max. A – 0.385 – 9.78 A1 0.265 0.285 6.73 7.24 A2 0.255 0.275 6.48 6.99 A3 – 0.015 – 0.38 B 0.018 0.022 0.46 0.56 D 0.835 0.860 21.21 21.84 E 0.560 0.590 14.22 14.99 eA eB 0.612 0.628 15.95 0.126 0.142 15.54 3.20 L 0.080 0.090 2.03 2.29 3.61 A2 A1 A3 A B L eA eB 4201973/A 08/01 NOTES: A. All linear dimensions are in millimeters. B. This drawing is subject to change without notice. www.ti.com 5 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third–party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. Mailing Address: Texas Instruments Post Office Box 655303 Dallas, Texas 75265 Copyright  2002, Texas Instruments Incorporated