参数资料
型号: DS1685SN-3
厂商: DALLAS SEMICONDUCTOR
元件分类: Timer or RTC
英文描述: 1 TIMER(S), REAL TIME CLOCK, PDSO24
封装: SOIC-24
文件页数: 36/39页
文件大小: 290K
代理商: DS1685SN-3
DS1685/DS1687
6 of 39
DS1685 ONLY
X1, X2 - Connections for a standard 32.768 kHz quartz crystal. For greatest accuracy, the DS1685 must
be used with a crystal that has a specified load capacitance of either 6 pF or 12.5 pF. The Crystal Select
(CS) bit in Extended Control Register 4B is used to select operation with a 6 pF or 12.5 pF crystal. The
crystal is attached directly to the X1 and X2 pins. There is no need for external capacitors or resistors.
Note: X1 and X2 are very high impedance nodes. It is recommended that they and the crystal be guard-
ringed with ground and that high frequency signals be kept away from the crystal area.
For more information on crystal selection and crystal layout considerations, please consult Application
Note 58, “Crystal Considerations with Dallas Real Time Clocks.” The DS1685 can also be driven by an
external 32.768 kHz oscillator. In this configuration, the X1 pin is connected to the external oscillator
signal and the X2 pin is floated.
VBAT - Battery input for any standard 3-volt lithium cell or other energy source. Battery voltage must be
held between 2.5 and 3.7 volts for proper operation.
POWER-DOWN/POWER-UP CONSIDERATIONS
The real-time clock function will continue to operate and all of the RAM, time, calendar, and alarm
memory locations remain nonvolatile regardless of the level of the VCC input. When VCC is applied to the
DS1685/DS1687 and reaches a level of greater than VPF (power fail trip point), the device becomes
accessible after tREC, provided that the oscillator is running and the oscillator countdown chain is not in
reset (see Register A). This time period allows the system to stabilize after power is applied.
The DS1685/DS1687 is available in either a 3-volt or a 5-volt device.
The 5-volt device is fully accessible and data can be written and read only when VCC is greater than
4.5 volts.
When VCC is below 4.5 volts, read and writes are inhibited. However, the timekeeping
function continues unaffected by the lower input voltage. As VCC falls below the greater of VBAT and
VBAUX, the RAM and timekeeper are switched over to a lithium battery connected either to the VBAT pin
or VBAUX pin.
The 3-volt device is fully accessible and data can be written or read only when VCC is greater than
2.7 volts. When VCC falls below VPF , access to the device is inhibited. If VPF is less than VBAT and
VBAUX, the power supply is switched from VCC to the backup supply (the greater of VBAT and VBAUX)
when VCC drops below VPF . If VPF is greater than VBAT and VBAUX, the power supply is switched from
VCC to the backup supply when VCC drops below the larger of VBAT and VBAUX.
When VCC falls below VPF, the chip is write-protected. With the possible exception of the KS , PWR , and
SQW pins, all inputs are ignored and all outputs are in a high impedance state.
相关PDF资料
PDF描述
DS1685Q-5 1 TIMER(S), REAL TIME CLOCK, PQCC28
DS1689SN 1 TIMER(S), REAL TIME CLOCK, PDSO28
DS1689S 1 TIMER(S), REAL TIME CLOCK, PDSO28
DS1693 1 TIMER(S), REAL TIME CLOCK, PDMA28
DS1689 1 TIMER(S), REAL TIME CLOCK, PDIP28
相关代理商/技术参数
参数描述
DS1685SN-3+ 功能描述:实时时钟 3V/5V RTC RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 总线接口:I2C 日期格式:DW:DM:M:Y 时间格式:HH:MM:SS RTC 存储容量:64 B 电源电压-最大:5.5 V 电源电压-最小:1.8 V 最大工作温度:+ 85 C 最小工作温度: 安装风格:Through Hole 封装 / 箱体:PDIP-8 封装:Tube
DS1685SN-5 功能描述:实时时钟 3V/5V RTC RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 总线接口:I2C 日期格式:DW:DM:M:Y 时间格式:HH:MM:SS RTC 存储容量:64 B 电源电压-最大:5.5 V 电源电压-最小:1.8 V 最大工作温度:+ 85 C 最小工作温度: 安装风格:Through Hole 封装 / 箱体:PDIP-8 封装:Tube
DS1685SN-5/T& 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:3V/5V Real-Time Clocks
DS1685SN-5/T&R 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述:
DS1685SN-5/T&R 功能描述:实时时钟 RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 总线接口:I2C 日期格式:DW:DM:M:Y 时间格式:HH:MM:SS RTC 存储容量:64 B 电源电压-最大:5.5 V 电源电压-最小:1.8 V 最大工作温度:+ 85 C 最小工作温度: 安装风格:Through Hole 封装 / 箱体:PDIP-8 封装:Tube