参数资料
| 型号： | DS1677E |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 16/18页 |
| 文件大小： | 0K |
| 描述： | IC CTRLR SYSTEM PORT 20-TSSOP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 74 |
| 类型： | 便携系统控制器 |
| 特点： | 警报器，闰年，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： | 3 线串口 |
| 电源电压： | 4.5 V ~ 5.5 V |
| 电压 - 电源，电池： | 2.5 V ~ 3.7 V |
| 工作温度： | 0°C ~ 70°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 20-TSSOP（0.173"，4.40mm 宽） |
| 供应商设备封装： | 20-TSSOP |
| 包装： | 管件 |
DS1677
7 of 18
STATUS REGISTER
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
CU
LOBAT
0
IRQF
CU (Conversion Update In Progress). When this bit is a one, an update to the ADC Register (register
0Eh) will occur within 488 μs. When this bit is a zero, an update to the ADC Register will not occur for at
least 244 μs.
LOBAT (Low Battery Flag). This bit reflects the status of the backup power source connected to the
VBAT pin. When VBAT is greater than 2.5V, LOBAT is set to a logic 0. When VBAT is less than 2.3V,
LOBAT is set to a logic 1.
IRQF (Interrupt Request Flag). A logic 1 in the Interrupt Request Flag bit indicates that the current
time has matched the time of day Alarm registers. If the AIE bit is also a logic 1, the INT pin will go
high. IRQF is cleared by reading or writing to any of the alarm registers.
POWER-UP DEFAULT STATES
These bits are set to a one upon initial power-up: EOSC , TD0 and TD1. These bits are cleared upon
initial power-up: WP, AIS1, and AIS0.
NONVOLATILE SRAM CONTROLLER
The DS1677 provides automatic backup and write protection for an external SRAM. This function is
provided by gating the chip enable signal and by providing a constant power supply through the VCCO pin.
The DS1677 nonvolatizes the external SRAM by write protecting the SRAM and by providing a back–up
power supply in the absence of VCC. When VCC falls below VPF, access to the external SRAM is
prohibited by forcing CE0 high regardless of the level of CEI . Upon power-up, access is prohibited until
the end of tRPU.
POWER-FAIL COMPARATOR
The PFI input is connected to an internal reference. If PFI is less than 1.25V, PFO goes low. The power-
fail comparator can be used as an undervoltage detector to signal an impending power supply failure.
PFO
can be used as a
P interrupt input to prepare for power-down. For battery conservation, the
comparator is turned off and PFO is held low when in battery-backed mode
ADDING HYSTERESIS TO THE POWER-FAIL COMPARATOR
Hysteresis adds a noise margin to the power-fail comparator and prevents PFO from oscillating when VIN
is near the power-fail comparator trip point. Figure 8 shows how to add hysteresis to the power-fail
comparator. Select the ratio of R1 and R2 such that PFI sees 1.25V when VIN falls to the desired trip point
(VTRIP). Resistors R2 and R3 add hysteresis. R3 will typically be an order of magnitude greater than R1 or
R2. R3 should be chosen in manner to prevent it from loading down the PFO pin. Capacitor C1 adds
noise filtering and has a value of typically 1.0
F. See Figure 8 for a schematic diagram and equations.
相关PDF资料 |
PDF描述 |
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相关代理商/技术参数 |
参数描述 |
|---|---|
| DS1677E+ | 功能描述:实时时钟 Portable System Controller 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 |
| DS1677E-5 | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Portable System Controller(275.85 k) |
| DS1678 | 功能描述:实时时钟 Real-Time Event Recorder 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 |
| DS1678+ | 功能描述:实时时钟 Real-Time Event Recorder 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 |
| DS1678J | 制造商:未知厂家 制造商全称:未知厂家 功能描述:2-Input Digital Multiplexer |
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