参数资料
型号: 1337DVGI
厂商: INTEGRATED DEVICE TECHNOLOGY INC
元件分类: 时钟/数据恢复及定时提取
英文描述: REAL TIME CLOCK, PDSO8
封装: 3 MM, ROHS COMPLIANT, MSOP-8
文件页数: 18/24页
文件大小: 362K
代理商: 1337DVGI
IDT1337
REA LTIME CLOCK WITH SERIAL INTERFACE
RTC
IDT REAL-TIME CLOCK WITH I2C SERIAL INTERFACE
3
IDT1337
REV J 111009
Typical Operating Circuit
Detailed Description
Communications to and from the IDT1337 occur serially
over an I2C bus. The IDT1337 operates as a slave device on
the serial bus. Access is obtained by implementing a START
condition and providing a device identification code,
followed by data. Subsequent registers can be accessed
sequentially until a STOP condition is executed. The device
is fully accessible through the I2C interface whenever VCC
is between 5.5 V and 1.8 V. I2C operation is not guaranteed
when VCC is below 1.8 V. The IDT1337 maintains the time
and date when VCC is as low as 1.3 V.
The following sections discuss in detail the Oscillator block,
Clock/Calendar Register Block and Serial I2C block.
Oscillator Block
Selection of the right crystal, correct load capacitance and
careful PCB layout are important for a stable crystal
oscillator. Due to the optimization for the lowest possible
current in the design for these oscillators, losses caused by
parasitic currents can have a significant impact on the
overall oscillator performance. Extra care needs to be taken
to maintain a certain quality and cleanliness of the PCB.
Crystal Selection
The key parameters when selecting a 32 kHz crystal to work
with IDT1337 RTC are:
Recommended Load Capacitance
Crystal Effective Series Resistance (ESR)
Frequency Tolerance
Effective Load Capacitance
Please see diagram below for effective load capacitance
calculation. The effective load capacitance (CL) should
match the recommended load capacitance of the crystal in
order for the crystal to oscillate at its specified parallel
resonant frequency with 0ppm frequency error.
In the above figure, X1 and X2 are the crystal pins of our
device. Cin1 and Cin2 are the internal capacitors which
include the X1 and X2 pin capacitance. Cex1 and Cex2 are
the external capacitors that are needed to tune the crystal
frequency. Ct1 and Ct2 are the PCB trace capacitances
between the crystal and the device pins. CS is the shunt
capacitance of the crystal (as specified in the crystal
manufacturer's datasheet or measured using a network
analyzer).
CPU
X1
X2
VCC
SQW/INTB
INTA
GND
SDA
SCL
CRYSTAL
IDT1337
VCC
2k
VCC
10k
相关PDF资料
PDF描述
1338-31DCGI 1 TIMER(S), REAL TIME CLOCK, PDSO8
1339-2DVGI 1 TIMER(S), REAL TIME CLOCK, PDSO8
1339-31DCGI8 1 TIMER(S), REAL TIME CLOCK, PDSO8
13715-806-XTD 300 MHz, OTHER CLOCK GENERATOR, PDSO16
1374610-3 INTERCONNECTION DEVICE
相关代理商/技术参数
参数描述
1337DVGI8 制造商:Integrated Device Technology Inc 功能描述:REAL TIME CLOCK SERL 8TSSOP - Tape and Reel
1337G0 制造商:未知厂家 制造商全称:未知厂家 功能描述:Peripheral IC
1337G1 功能描述:重负荷电源连接器 PCB45 HORIZ (TOP) RA LP CONT. RoHS:否 制造商:Hirose Connector 系列:PS2 产品类型:Connectors 位置/触点数量: 端接类型:Crimp 触点材料: 触点电镀:Gold 电压额定值: 电流额定值:300 A 附件类型:
1337G2 制造商:未知厂家 制造商全称:未知厂家 功能描述:Peripheral IC
1337GCSRI 功能描述:实时时钟 实时时钟 with Embedded Crystal 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