Os motores de busca de Datasheet de Componentes eletrônicos |
|
ISL1209IU10 Folha de dados(PDF) 8 Page - Intersil Corporation |
|
ISL1209IU10 Folha de dados(HTML) 8 Page - Intersil Corporation |
8 / 24 page 8 FN6109.1 September 27, 2005 has occurred and requests action. It is an open drain active low output. • Frequency Output Mode. The pin outputs a clock signal which is related to the crystal frequency. The frequency output is user selectable and enabled via the I2C bus. It is an open drain active low output. Serial Clock (SCL) The SCL input is used to clock all serial data into and out of the device. The input buffer on this pin is always active (not gated). It is disabled when the backup power supply on the VBAT pin is activated to minimize power consumption. Serial Data (SDA) SDA is a bidirectional pin used to transfer data into and out of the device. It has an open drain output and may be ORed with other open drain or open collector outputs. The input buffer is always active (not gated) in normal mode. An open drain output requires the use of a pull-up resistor. The output circuitry controls the fall time of the output signal with the use of a slope controlled pull-down. The circuit is designed for 400kHz I2C interface speeds. It is disabled when the backup power supply on the VBAT pin is activated. VDD, GND Chip power supply and ground pins. The device will operate with a power supply from VDD=2.7V to 5.5VDC. A 0.1µF capacitor is recommended on the VDD pin to ground. Functional Description Power Control Operation The power control circuit accepts a VDD and a VBAT input. Many types of batteries can be used with Intersil RTC products. For example, 3.0V or 3.6V Lithium batteries are appropriate, and battery sizes are available that can power the ISL1209 for up to 10 years. Another option is to use a Super Cap for applications where VDD is interrupted for up to a month. See the Applications Section for more information. Normal Mode (VDD) to Battery Backup Mode (VBAT) To transition from the VDD to VBAT mode, both of the following conditions must be met: Condition 1: VDD < VBAT - VBATHYS where VBATHYS ≈ 50mV Condition 2: VDD < VTRIP where VTRIP ≈ 2.2V Battery Backup Mode (VBAT) to Normal Mode (VDD) The ISL1209 device will switch from the VBAT to VDD mode when one of the following conditions occurs: Condition 1: VDD > VBAT + VBATHYS where VBATHYS ≈ 50mV Condition 2: VDD > VTRIP + VTRIPHYS where VTRIPHYS ≈ 30mV These power control situations are illustrated in Figures 9 and 10. The I2C bus is deactivated in battery backup mode to provide lower power. Aside from this, all RTC functions are operational during battery backup mode. Except for SCL and SDA, all the inputs and outputs of the ISL1209 are active during battery backup mode unless disabled via the control register. The User SRAM is operational in battery backup mode down to 1.8V. Power Failure Detection The ISL1209 provides a Real Time Clock Failure Bit (RTCF) to detect total power failure. It allows users to determine if the device has powered up after having lost all power to the device (both VDD and VBAT). Low Power Mode The normal power switching of the ISL1209 is designed to switch into battery backup mode only if the VDD power is lost. This will ensure that the device can accept a wide range of backup voltages from many types of sources while reliably switching into backup mode. Another mode, called Low VBAT - VBATHYS VBAT VBAT + VBATHYS BATTERY BACKUP MODE VDD VTRIP 2.2V 1.8V FIGURE 9. BATTERY SWITCHOVER WHEN VBAT < VTRIP FIGURE 10. BATTERY SWITCHOVER WHEN VBAT > VTRIP VTRIP VBAT VTRIP + VTRIPHYS BATTERY BACKUP MODE VDD VTRIP 3.0V 2.2V ISL1209 ∆ |
Nº de peça semelhante - ISL1209IU10 |
|
Descrição semelhante - ISL1209IU10 |
|
|
Ligação URL |
Privacy Policy |
ALLDATASHEETPT.COM |
ALLDATASHEET é útil para você? [ DONATE ] |
Sobre Alldatasheet | Publicidade | Contato conosco | Privacy Policy | roca de Link | Lista de Fabricantes All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |