BQ4845 RTC IC W NVSRAM 控制器、看门狗定时器、加电复位、中断与低电池电量警告

BQ4845 描述

The bq4845 Real-Time Clock is a low-power microprocessor peripheral that integrates a time-of-day clock, a 100-year calendar, and a CPU supervisor in a 28-pin SOIC or DIP. The bq4845 is ideal for fax machines, copiers, industrial control systems, point-of-sale terminals, data loggers, and computers. The bq4845 provides direct connections for a 32.768KHz quartz crystal and a 3V backup battery. Through the use of the conditional chip enable output (CE\OUT) and battery voltage output (VOUT) pins, the bq4845 can write-protect and make nonvolatile external SRAMs. The backup cell powers the real-time clock and maintains SRAM information in the absence of system voltage. The bq4845 contains a temperature-compensated reference and comparator circuit that monitors the status of its voltage supply

	BQ4845
Supply Voltage(V)	5
Bus Interface	Parallel
Operating Temperature Range(°C)	-40 to 85,0 to 70
Pin/Package	28PDIP, 28SOIC
Approx. Price (US$)	2.50 \| 1ku
RTC Bytes	16

BQ4845 特性

Real-Time Clock counts seconds through years in BCD format
On-chip battery-backup switchover circuit with nonvolatile control for external SRAM
Less than 500nA of clock operation current in backup mode
Microprocessor reset valid to VCC =VSS
Independent watchdog timer with a programmable time-out period
Power-fail interrupt warning
Programmable clock alarm interrupt active in battery-backup mode
Programmable periodic interrupt
Battery-low warning

BQ4845 芯片订购指南

器件	状态	温度 (oC)	价格（美元）	封装 \| 引脚	封装数量 \| 封装载体	丝印标记
BQ4845P-A4	ACTIVE	0 to 70	2.50 \| 1ku	PDIP (N) \| 28	13 \| TUBE	4845P -A4
BQ4845S-A4	ACTIVE	0 to 70	3.00 \| 1ku	SOIC (DW) \| 28	20 \| TUBE	4845S -A4
BQ4845S-A4G4	ACTIVE	0 to 70	3.00 \| 1ku	SOIC (DW) \| 28	20 \| TUBE	4845S -A4
BQ4845S-A4N	ACTIVE	-40 to 85	3.00 \| 1ku	SOIC (DW) \| 28	20 \| TUBE	4845S -A4
BQ4845S-A4NG4	ACTIVE	-40 to 85	3.00 \| 1ku	SOIC (DW) \| 28	20 \| TUBE	4845S -A4
BQ4845S-A4NTR	ACTIVE		2.50 \| 1ku	SOIC (DW) \| 28	1000 \| LARGE T&R	4845S -A4
BQ4845S-A4NTRG4	ACTIVE		2.50 \| 1ku	SOIC (DW) \| 28	1000 \| LARGE T&R	4845S -A4
BQ4845S-A4TR	ACTIVE	0 to 70	2.50 \| 1ku	SOIC (DW) \| 28	1000 \| LARGE T&R	4845S -A4
BQ4845S-A4TRG4	ACTIVE	0 to 70		SOIC (DW) \| 28		4845S -A4

BQ4845 质量与无铅数据

器件	环保计划*	铅/焊球涂层	MSL 等级/回流焊峰	环保信息与无铅 (Pb-free)	DPPM / MTBF / FIT 率
BQ4845P-A4	Pb-Free (RoHS)	A42 SN	N/A for Pkg Type	BQ4845P-A4	BQ4845P-A4
BQ4845S-A4	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	BQ4845S-A4	BQ4845S-A4
BQ4845S-A4G4	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	BQ4845S-A4G4	BQ4845S-A4G4
BQ4845S-A4N	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	BQ4845S-A4N	BQ4845S-A4N
BQ4845S-A4NG4	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	BQ4845S-A4NG4	BQ4845S-A4NG4
BQ4845S-A4NTR	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	BQ4845S-A4NTR	BQ4845S-A4NTR
BQ4845S-A4NTRG4	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	BQ4845S-A4NTRG4	BQ4845S-A4NTRG4
BQ4845S-A4TR	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	BQ4845S-A4TR	BQ4845S-A4TR

BQ4845 应用技术支持与电子电路设计开发资源下载

BQ4845 数据资料 dataSheet 下载.PDF
TI 德州仪器实时时钟产品选型与价格 . xls
PowerPAD™ Thermally Enhanced Package (PDF 1040 KB)
全面认识开关型电源中的BUCK-BOOST功率级 (Rev. A) (PDF 2206 KB)
Shelf-Life Evaluation of Lead-Free Component Finishes (PDF 1305 KB)
PowerPAD™ Made Easy (PDF 57 KB)
标准线性产品交叉参考 (Rev. D) (PDF 1058 KB)
模数规格和性能特性术语表 (Rev. A) (PDF 1993 KB)
所选封装材料的热学和电学性质 (PDF 645 KB)
高速数据转换 (PDF 1967 KB)

BQ4845 相关工具

名称	型号	公司	工具/软件类型
BQ4845 评估模块	BQ4845EVM	Texas Instruments	开发电路板/EVM