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參數(shù)資料
| 型號： | DS14285SN+T&R |
| 廠商： | Maxim Integrated Products |
| 文件頁數(shù)： | 24/26頁 |
| 文件大?。?/td> | 0K |
| 描述： | IC RTC W/NV RAM CNTRL 24-SOIC |
| 標準包裝： | 1,000 |
| 類型： | 時鐘/日歷 |
| 特點： | 警報器，夏令時，閏年，NVSRAM，方波輸出 |
| 存儲容量： | 114B |
| 時間格式： | HH:MM:SS（12/24 小時） |
| 數(shù)據(jù)格式： | YY-MM-DD-dd |
| 接口： | 并聯(lián) |
| 電源電壓： | 4.5 V ~ 5.5 V |
| 電壓 - 電源，電池： | 2.5 V ~ 3.6 V |
| 工作溫度： | -40°C ~ 85°C |
| 安裝類型： | 表面貼裝 |
| 封裝/外殼： | 24-SOIC（0.295"，7.50mm 寬） |
| 供應(yīng)商設(shè)備封裝： | 24-SOIC W |
| 包裝： | 帶卷 (TR) |
DS14285/DS14287
7 of 26
POWER-DOWN/POWER-UP CONSIDERATIONS
The real time clock function will continue to operate and all of the RAM, time, calendar, and alarm
memory locations remain nonvolatile regardless of the level of the VCC input. When VCC is applied to the
DS14285/DS14287 and reaches a level of greater than 4.25 volts (typical), the device becomes accessible
after 200 ms, provided that the oscillator is running and the oscillator countdown chain is not in reset (see
Register A). This time period allows the system to stabilize after power is applied. When VCC falls below
4.25 volts (typical), the chip select input is internally forced to an inactive level regardless of the value of
CS
at the input pin. The DS14285/DS14287 is, therefore, write-protected. When the DS14285/DS14287
is in a write-protected state, all inputs are ignored and all outputs are in a high impedance state. When
VCC falls below a level of approximately 3 volts, the external VCC supply is switched off and an internal
lithium energy source supplies power to the Real-time Clock and the RAM memory.
An external SRAM can be made nonvolatile by using the VCCO and SRAM chip enable pins (see Figure
1). Nonvolatile control of the external SRAM is analogous to that of the real time clock registers. When
VCC slews down during a power fail, CEO is driven to an inactive level regardless CEI . This write
protection occurs when VCC is less than 4.25 volts (typical).
During power up, when VCC reaches a level of greater than 4.25 volts (typical), CEO will reflect CEI
after 200 ms. During power-valid operation, the CEI input is passed to the CEO output with a
propagation delay of less than 10 ns.
When VCC is above a level of approximately 3V, the external SRAM will be powered by VCC through the
VCCO pin. When VCC is below a level of approximately 3V, the external SRAM will be powered by the
internal lithium cell through the VCCO pin. An internal comparator and switch determine whether VCCO is
powered by VCC or the internal lithium cell.
When the device is in battery backup mode, the energy source connected to the VBAT pin in the case of
the DS14285, or the internal lithium cell in the case of the DS14287 can power an external SRAM for an
extended period of time. The amount of time that the lithium cell can supply power to the external SRAM
is a function of the data retention current of the SRAM. The capacity of the lithium cell that is
encapsulated within the DS14287 module is 130 mAh. If an SRAM with a data retention current of less
than 1
A is used and the oscillator current is 300 nA (typical), the cumulative data retention time is
calculated at more than 11 years.
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DS14287 | 功能描述:實時時鐘 RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 總線接口:I2C 日期格式:DW:DM:M:Y 時間格式:HH:MM:SS RTC 存儲容量:64 B 電源電壓-最大:5.5 V 電源電壓-最小:1.8 V 最大工作溫度:+ 85 C 最小工作溫度: 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube |
| DS14287+ | 功能描述:實時時鐘 RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 總線接口:I2C 日期格式:DW:DM:M:Y 時間格式:HH:MM:SS RTC 存儲容量:64 B 電源電壓-最大:5.5 V 電源電壓-最小:1.8 V 最大工作溫度:+ 85 C 最小工作溫度: 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube |
| DS1-48-0001 | 功能描述:固定電感器 DS Storage choke 3.15A RoHS:否 制造商:AVX 電感:10 uH 容差:20 % 最大直流電流:1 A 最大直流電阻:0.075 Ohms 工作溫度范圍:- 40 C to + 85 C 自諧振頻率:38 MHz Q 最小值:40 尺寸:4.45 mm W x 6.6 mm L x 2.92 mm H 屏蔽:Shielded 端接類型:SMD/SMT 封裝 / 箱體:6.6 mm x 4.45 mm |
| DS1-48-0002 | 功能描述:固定電感器 DS Storage choke 4A RoHS:否 制造商:AVX 電感:10 uH 容差:20 % 最大直流電流:1 A 最大直流電阻:0.075 Ohms 工作溫度范圍:- 40 C to + 85 C 自諧振頻率:38 MHz Q 最小值:40 尺寸:4.45 mm W x 6.6 mm L x 2.92 mm H 屏蔽:Shielded 端接類型:SMD/SMT 封裝 / 箱體:6.6 mm x 4.45 mm |
| DS1-48-0003 | 制造商:Schurter Electronic Components 功能描述: |
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