参数资料
型号: ISL12029IB30AZ-T
厂商: Intersil
文件页数: 16/29页
文件大小: 0K
描述: IC RTC/CALENDAR EEPROM 14-SOIC
标准包装: 2,500
类型: 时钟/日历
特点: 警报器,闰年,监控器,监视计时器
时间格式: HH:MM:SS(12/24 小时)
数据格式: YY-MM-DD-dd
接口: I²C,2 线串口
电源电压: 2.7 V ~ 5.5 V
电压 - 电源,电池: 1.8 V ~ 5.5 V
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 14-SOIC(0.154",3.90mm 宽)
供应商设备封装: 14-SOICN
包装: 带卷 (TR)
23
FN6206.10
December 16, 2010
Application Section
Crystal Oscillator and Temperature Compensation
Intersil has now integrated the oscillator compensation
circuity on-chip, to eliminate the need for external
components and adjust for crystal drift over-temperature and
enable very high accuracy time keeping (<5ppm drift).
The Intersil RTC family uses an oscillator circuit with on-chip
crystal compensation network, including adjustable
load-capacitance. The only external component required is
the crystal. The compensation network is optimized for
operation with certain crystal parameters, which are
common in many of the surface mount or tuning-fork crystals
available today. Table 9 summarizes these parameters.
Table 10 contains some crystal manufacturers and part
numbers that meet the requirements for the Intersil RTC
products.
The turnover-temperature in Table 9 describes the
temperature where the apex of the of the drift vs temperature
curve occurs. This curve is parabolic with the drift increasing
as (T-T0)2. For an Epson MC-405 device, for example, the
turnover-temperature is typically +25°C, and a peak drift of
>110ppm occurs at the temperature extremes of -40 and
+85°C. It is possible to address this variable drift by adjusting
the load capacitance of the crystal, which will result in
predictable change to the crystal frequency. The Intersil RTC
family allows this adjustment over-temperature since the
devices include on-chip load capacitor trimming. This control
is handled by the Analog Trimming Register, or ATR, which
has 6 bits of control. The load capacitance range covered by
the ATR circuit is approximately 3.25pF to 18.75pF, in
0.25pF increments. Note that actual capacitance would also
include about 2pF of package related capacitance. In-circuit
tests with commercially available crystals demonstrate that
this range of capacitance allows frequency control from
+116ppm to -37ppm, using a 12.5pF load crystal.
In addition to the analog compensation afforded by the
adjustable load capacitance, a digital compensation feature
is available for the Intersil RTC family. There are 3 bits
known as the Digital Trimming Register or DTR, and they
operate by adding or skipping pulses in the clock signal. The
range provided is ±30ppm in increments of 10ppm. The
default setting is 0ppm. The DTR control can be used for
coarse adjustments of frequency drift over-temperature or
for crystal initial accuracy correction.
A final application for the ATR control is in-circuit calibration
for high accuracy applications, along with a temperature
sensor chip. Once the RTC circuit is powered up with battery
backup, the IRQ/FOUT output is set at 32.768kHz and
frequency drift is measured. The ATR control is then
adjusted to a setting which minimizes drift. Once adjusted at
a particular temperature, it is possible to adjust at other
discrete temperatures for minimal overall drift, and store the
resulting settings in the EEPROM. Extremely low overall
temperature drift is possible with this method. The Intersil
evaluation board contains the circuitry necessary to
implement this control.
TABLE 9. CRYSTAL PARAMETERS REQUIRED FOR INTERSIL RTCs
PARAMETER
MIN
TYP
MAX
UNITS
NOTES
Frequency
32.768
kHz
Frequency Tolerance
±100
ppm
Down to 20ppm if desired
Turnover-Temperature
20
25
30
°C
Typically the value used for most crystals
Operating Temperature Range
-40
85
°C
Parallel Load Capacitance
12.5
pF
Equivalent Series Resistance
50
k
Ω
For best oscillator performance
TABLE 10. CRYSTAL MANUFACTURERS
MANUFACTURER
PART NUMBER
TEMP RANGE
(°C)
+25°C FREQUENCY
TOLERANCE
(ppm)
Citizen
CM201, CM202, CM200S
-40 to +85
±20
Epson
MC-405, MC-406
-40 to +85
±20
Raltron
RSM-200S-A or B
-40 to +85
±20
SaRonix
32S12A or B
-40 to +85
±20
Ecliptek
ECPSM29T-32.768K
-10 to +60
±20
ECS
ECX-306/ECX-306I
-10 to +60
±20
Fox
FSM-327
-40 to +85
±20
ISL12029, ISL12029A
相关PDF资料
PDF描述
AD5259BRMZ50 IC POT DGTL 50K 256POS 10-MSOP
ISL12029IB27AZ-T IC RTC/CALENDAR EEPROM 14-SOIC
ISL12028IB30AZ-T IC RTC/CALENDAR EEPROM 14-SOIC
ISL12028IBAZ-T IC RTC/CALENDAR EEPROM 14-SOIC
D38999/20MH21PN CONN RCPT 21POS WALL MNT W/PINS
相关代理商/技术参数
参数描述
ISL12029IBAZ 功能描述:实时时钟 REAL TIME CLKRTC W/ EPROM 4 64VSET 14 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
ISL12029IBAZ-T 功能描述:实时时钟 REAL TIME CLKRTC W/ EPROM 4 64VSET 14 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
ISL12029IBZ 功能描述:实时时钟 REAL TIME CLKRTC W/ EPROM IN 14LD 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
ISL12029IBZ-T 功能描述:实时时钟 REAL TIME CLKRTC W/ EPROM IN 14LD 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
ISL12029IV27AZ 功能描述:实时时钟 REAL TIME CLKRTC W/ EPROM 2 92VSET 14 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