参数资料
| 型号： | ISL12032IVZ |
| 厂商： | Intersil |
| 文件页数： | 17/26页 |
| 文件大小： | 0K |
| 描述： | IC RTC LP BATT BACK SRAM 14TSSOP |
| 产品培训模块： | Solutions for Industrial Control Applications |
| 标准包装： | 960 |
| 类型： | 时间事件记录器 |
| 特点： | 警报器，SRAM，涓流充电器 |
| 存储容量： | 128B |
| 时间格式： | HH:MM:SS:hh（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-TSSOP（0.173"，4.40mm 宽） |
| 供应商设备封装： | 14-TSSOP |
| 包装： | 管件 |
24
FN6618.3
May 5, 2011
Application Section
Oscillator Crystal Requirements
The ISL12032 uses a standard 32.768kHz crystal. Either
through hole or surface mount crystals can be used.
Table 28 lists some recommended surface mount crystals
and the parameters of each. This list is not exhaustive and
other surface mount devices can be used with the ISL12032
if their specifications are very similar to the devices listed.
The crystal should have a required parallel load capacitance
of 12.5pF and an equivalent series resistance of less than
50k
Ω. The crystal’s temperature range specification should
match the application. Many crystals are rated for -10°C to
+60°C (especially through hole and tuning fork types), so an
appropriate crystal should be selected if extended
temperature range is required.
Layout Considerations
The crystal input at X1 has a very high impedance, and
oscillator circuits operating at low frequencies (such as
32.768kHz) are known to pick up noise very easily if layout
precautions are not followed. Most instances of erratic
clocking or large accuracy errors can be traced to the
susceptibility of the oscillator circuit to interference from
adjacent high speed clock or data lines. Careful layout of the
RTC circuit will avoid noise pickup and ensure accurate
clocking.
Two main precautions for crystal PC board layout should be
followed:
1. Do not run the serial bus lines or any high speed logic
lines in the vicinity of the crystal. These logic level lines
can induce noise in the oscillator circuit to cause
misclocking.
2. Add a ground trace around the crystal with one end
terminated at the chip ground. This will provide
termination for emitted noise in the vicinity of the RTC
device.
In addition, it is a good idea to avoid a ground plane under
the X1 and X2 pins and the crystal, as this will affect the load
capacitance and therefore the oscillator accuracy of the
circuit. If the FOUT pin is used as a clock, it should be routed
away from the RTC device as well. The traces for the VBAT
and VDD pins can be treated as a ground, and should be
routed around the crystal.
AC Input Circuits
The AC input ideally will have a 2.5VP-P sine wave at the
input, so this is the target for any signal conditioning circuitry
for the 50/60Hz waveform. Note that the peak-to-peak
amplitude can range from 1VP-P up to VDD, although it is
best to keep the max signal level just below VDD. The AC
input provides DC offset so AC coupling with a series
capacitor is advised.
If the AC power supply has a transformer, the secondary
output can be used for clocking with a resistor divider and
series AC coupling capacitor. A sample circuit is shown in
peak-to-peak range on the secondary voltage in order to
match the input of the ISL12032. CIN can be sized to pass
up to 300Hz or so, and in most cases, 0.47F should be the
selected value for a ±20% tolerance device.
The AC input to the IS12032 can be damaged if subjected to
a normal AC waveform when VDD is powered down. this can
happen in circuits where there is a local LDO or power
switch for placing circuitry in standby, while the AC main is
still switched ON. Figure 11 shows a modified version of the
Figure 12 circuit, which uses an emitter follower to
essentially turn off the AC input waveform if the VDD supply
goes down.
Using the ISL12032 with No AC Input
Some applications may need all the features of the
ISL12032 but do not have access to the power line AC clock,
or do not need the accuracy provided by that clock. In these
cases there is no problem using the crystal oscillator as the
primary clock source for the device.
The user must simply set the ACENB bit in register 13h to
“1”, which disables the AC input pin and forces the device to
use the crystal oscillator exclusively for the RTC and FOUT
clock source. Setting this bit to “1” also will cause the
ACRDY bit in the SRAC register to be set to “1”, indicating
that there can be no fault with the AC input clock since it is
not used.
TABLE 28. SUGGESTED SURFACE MOUNT CRYSTALS
MANUFACTURER
PART NUMBER
Citizen
CM200S
Epson
MC-405, MC-406
Raltron
RSM-200S
SaRonix
32S12
Ecliptek
ECPSM29T-32.768K
ECS
ECX-306
Fox
FSM-327
ISL12032
相关PDF资料 |
PDF描述 |
|---|---|
| ISL12057IUZ | IC RTC/CALENDAR I2C 8-MSOP |
| ISL12058IUZ | IC RTC/CALENDAR I2C-BUS 8-MSOP |
| ISL12059IBZ | IC RTC/CALENDAR I2C-BUS 8-SOIC |
| ISL12082IUZ | IC RTC I2C LO-POWER 10-MSOP |
| ISL1208IU8-TK | IC RTC/CALENDAR I2C 8-MSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL12032IVZ-T | 功能描述:实时时钟 REAL TIME CLK W/ EEPROM 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 |
| ISL12057 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Low Cost and Low Power I2C RTC Real Time Clock/Calendar |
| ISL12057IBZ | 功能描述:实时时钟 REAL TIME CLK W/ ALARM DS1337 COMP 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 |
| ISL12057IBZ-T | 功能描述:实时时钟 REAL TIME CLK W/ ALARM DS1337 COMP 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 |
| ISL12057IRUZ-T | 功能描述:实时时钟 REAL TIME CLK W/ ALARM DS1337 COMP 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 |
发布紧急采购，3分钟左右您将得到回复。