DS1689/DS1693
2 of 36
PIN DESCRIPTION
PIN
SO
EDIP
NAME
FUNCTION
1
VBAUX
Auxiliary Battery Supply. Auxiliary battery input required for
kickstart and wake-up features. This input also supports
clock/calendar and External NV RAM if VBAT is at lower voltage or
is not present. A standard +3V lithium cell or other energy source
can be used. Battery voltage must be held between +2.5V and +3.7V
for proper operation. If VBAUX is not going to be used it should be
grounded and auxiliary battery enable bit bank 1, register 4BH,
should = 0.
2, 3
X1, X2
Connections for Standard 32.768kHz Quartz Crystal. For greatest
accuracy, the DS1689 must be used with a crystal that has a
specified load capacitance of either 6pF or 12.5pF. The crystal select
(CS) bit in Extended Control Register 4B is used to select operation
with a 6pF or 12.5pF 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 by 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, refer to Application Note 58: Crystal Considerations
with Dallas Real Time Clocks. The DS1689 can also be driven by an
external 32.768kHz oscillator. In this configuration, the X1 pin is
connected to the external oscillator signal and the X2 pin is floated.
4
RCLR
Active-Low RAM Clear Input. If enabled by software, taking
RCLR
low will result in the clearing of the 114 bytes of user RAM. When
enabled,
RCLR can be activated whether or not VCC is present.
5–12
AD0–AD7
Multiplexed Address/Data Bus. Multiplexed buses save pins because
address information and data information time-share the same signal
paths. The addresses are present during the first portion of the bus
cycle and the same pins and signal paths are used for data in the
second portion of the cycle. Address/data multiplexing does not slow
the access time of the DS1689 since the bus change from address to
data occurs during the internal RAM access time. Addresses must be
valid prior to the latter portion of ALE, at which time the
DS1689/DS1693 latches the address. Valid write data must be
present and held stable during the latter portion of the
WR pulse. In a
read cycle, the DS1689/
DS1693 outputs 8 bits of data during the latter portion of the
RD
pulse. The read cycle is terminated and the bus returns to a high
impedance state as
RD transitions high. The address/data bus also
serves as a bidirectional data path for the external extended RAM.
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相关代理商/技术参数
DS1689SN+T&R-W 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
DS1689SN+W 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
DS1689S-TRL 功能描述:IC RTC SER W/NV RAM CTRL 28-SOIC RoHS:否 类别:集成电路 (IC) >> 时钟/计时 - 实时时钟 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:- 类型:时钟/日历 特点:警报器,闰年,SRAM 存储容量:- 时间格式:HH:MM:SS(12/24 小时) 数据格式:YY-MM-DD-dd 接口:SPI 电源电压:2 V ~ 5.5 V 电压 - 电源,电池:- 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-WDFN 裸露焊盘 供应商设备封装:8-TDFN EP 包装:管件
DS1691 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
DS1691 WAF 制造商:Texas Instruments 功能描述:
DS1691/1692 WAF 制造商:Texas Instruments 功能描述:
DS1691A 制造商:NSC 制造商全称:National Semiconductor 功能描述:(RS-422/RS-423) Line Drivers with TRI-STATE Outputs
DS1691AJ/883 制造商:NSC 制造商全称:National Semiconductor 功能描述:(RS-422/RS-423) Line Drivers with TRI-STATE Outputs