2C Serial Real-Time Clock 9 of 20 DETAILED DESCRIPTION The DS1339 serial real-time clock (RTC)" />
參數(shù)資料
型號: DS1339U-3+T&R
廠商: Maxim Integrated Products
文件頁數(shù): 20/20頁
文件大?。?/td> 0K
描述: IC RTC I2C W/ALARM 8-USOP
產(chǎn)品培訓(xùn)模塊: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
標(biāo)準(zhǔn)包裝: 3,000
類型: 時鐘/日歷
特點: 警報器,閏年,方波輸出,涓流充電器
時間格式: HH:MM:SS(12/24 小時)
數(shù)據(jù)格式: YY-MM-DD-dd
接口: I²C,2 線串口
電源電壓: 2.7 V ~ 3.3 V
電壓 - 電源,電池: 1.3 V ~ 3.7 V
工作溫度: -40°C ~ 85°C
安裝類型: 表面貼裝
封裝/外殼: 8-TSSOP,8-MSOP(0.118",3.00mm 寬)
供應(yīng)商設(shè)備封裝: 8-uMAX
包裝: 帶卷 (TR)
DS1339 I
2C Serial Real-Time Clock
9 of 20
DETAILED DESCRIPTION
The DS1339 serial real-time clock (RTC) is a low-power clock/date device with two programmable time-of-day
alarms and a programmable square-wave output. Address and data are transferred serially through an I
2C bus.
The clock/date provides seconds, minutes, hours, day, date, month, and year information. The date at the end of
the month is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The
clock operates in either the 24-hour or 12-hour format with AM/PM indicator. The DS1339 has a built-in power-
sense circuit that detects power failures and automatically switches to the backup supply, maintaining time, date,
and alarm operation.
OPERATION
The DS1339 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 and data can be written and read when VCC is
greater than VPF. However, when VCC falls below V
PF, the internal clock registers are blocked from any access. If
VPF is less than VBACKUP, the device power is switched from VCC to VBACKUP when VCC drops below VPF. If VPF is
greater than VBACKUP, the device power is switched from VCC to VBACKUP when VCC drops below VBACKUP. The
registers are maintained from the VBACKUP source until VCC is returned to nominal levels. The block diagram in
Figure 3 shows the main elements of the serial real-time clock.
POWER CONTROL
The power-control function is provided by a precise, temperature-compensated voltage reference and a
comparator circuit that monitors the VCC level. The device is fully accessible and data can be written and read
when VCC is greater than VPF. However, when VCC falls below VPF, the internal clock registers are blocked from any
access. If VPF is less than VBACKUP, the device power is switched from VCC to VBACKUP when VCC drops below VPF. If
VPF is greater than VBACKUP, the device power is switched from VCC to VBACKUP when VCC drops below VBACKUP. The
registers are maintained from the VBACKUP source until VCC is returned to nominal levels (Table 1). After VCC returns
above VPF, read and write access is allowed after tREC (Figure 1). On the first application of power to the device the
time and date registers are reset to 01/01/00 01 00:00:00 (MM/DD/YY DOW HH:MM:SS).
Table 1. Power Control
SUPPLY CONDITION
READ/WRITE
ACCESS
POWERED
BY
VCC < VPF, VCC < VBACKUP
No
VBACKUP
VCC < VPF, VCC > VBACKUP
No
VCC
VCC > VPF, VCC < VBACKUP
Yes
VCC
VCC > VPF, VCC > VBACKUP
Yes
VCC
OSCILLATOR CIRCUIT
The DS1339 uses an external 32.768kHz crystal. The oscillator circuit does not require any external resistors or
capacitors to operate. Table 2 specifies several crystal parameters for the external crystal. Figure 3 shows a
functional schematic of the oscillator circuit. The startup time is usually less than 1 second when using a crystal
with the specified characteristics.
相關(guān)PDF資料
PDF描述
VI-JN2-MZ CONVERTER MOD DC/DC 15V 25W
VI-J5F-MZ CONVERTER MOD DC/DC 72V 25W
VE-240-MX-B1 CONVERTER MOD DC/DC 5V 75W
VE-BNZ-MY-F4 CONVERTER MOD DC/DC 2V 20W
MS3450L22-2SZ CONN RCPT 3POS WALL MNT W/SCKT
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS1340 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:I2C RTC with Trickle Charger
DS1340_06 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:I2C RTC with Trickle Charger
DS1340_11 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:I2C RTC with Trickle Charger
DS1340-3 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:I2C RTC with Trickle Charger
DS1340C-18 功能描述:實時時鐘 I2C RTC w/Trickle Charger 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