Electronic Components Datasheet Search |
|
ACT4921QI Datasheet(PDF) 21 Page - Active-Semi, Inc |
|
ACT4921QI Datasheet(HTML) 21 Page - Active-Semi, Inc |
21 / 35 page ACT4921QI Rev 1.0, 18-Jan-2018 Innovative PowerTM www.active-semi.com ActiveSwitcherTM is a trademark of Active-Semi Copyright © 2018 Active-Semi, Inc. 21 Table 4: Over Voltage Reference Settings VINS_OV_REF[2:0] OV Threshold (V) 000 Disabled 001 0.82 010 0.92 011 1.00 100 1.08 101 1.16 110 1.24 111 1.32 ENB The ENB pin enables the blocking FET, the buck converter, and the boost converter. They are disabled when ENB is low and enabled when ENB is high. ENB provides two main system level functions. The first is to isolate the storage capacitors as startup to allow faster system startup. ENB is typically held low by the system processor at startup. After the system starts up, the processor pulls ENB high to allow the boost converter to charge the storage caps. The second function is to provide fault isolation. In the event of a storage capacitor failure, ENB can be pulled low to isolate the capacitors from the system. This allows the system to continue operating until it can be safely shutdown. STR STR is the output to the storage capacitor bank. In normal operation the internal boost converter charges the storage capacitors through the STR pin. When the IC enters supplement mode, the internal buck converter uses the STR pin as its input to power the system. The STR pin is typically connected to hundreds of microfarads of storage capacitance. It always requires a 22uF or greater ceramic capacitor. See the Buck Converter section for more information. nIRQ—Interrupt ACT4921 has an interrupt pin to inform the host of any fault conditions. In general, any IC function with a status bit asserts nIRQ pin low if the status changes. The status changes can be masked by setting their corresponding register bits. If nIRQ is asserted low, the fault must be read before the IC deasserts nIRQ. If the fault remains after reading the status bits, nIRQ remains asserted. The status changes shown below assert the nIRQ pin: Input overvoltage, undervoltage Thermal warning, thermal shutdown eFuse VIN to VOUT over limits eFuse current warning and limit VB pin is not valid (VB or STR short) Storage capacitor overvoltage, undervoltage Supplemental mode active Buck operation faults Buck undervoltage shutdown REF LDO undervoltage nIRQ is an open-drain output and should be pulled up to an appropriate supply voltage with a 10kΩ or greater pull-up resistor. SCL, SDA SCL and SDA are the I2C clock and data pins to the IC They have standard I2C functionality. They are open- drain outputs and each require a pull-up resistor. The pull-up resistor is typically tied to the system’s uP IO pins. The pullup voltage can range from 1.8V to 5.0V. REF The REF pin is an internal bias voltage output pin. Connect a 1µF capacitor between REF and AGND. Do not apply an external load to the REF pin. BSET BSET sets the boost converter output voltage. The output voltage is a function of both a resistor connected between BSET and AGND as well as internal I2C register settings. See the Storage Boost Converter section for more information. ISET ISET sets the eFuse current limit with a resistor connected to AGND. See the eFuse section for more information. SS The SS pin uses a capacitor to AGND to control the eFuse softstart timing. See the eFuse section for more information. PGND The PGND pin is the buck and boost converters’ power ground. The internal FETs connect directly to the PGND pins. The power supply input and output capacitors should connect to the PGND pins. |
Similar Part No. - ACT4921QI |
|
Similar Description - ACT4921QI |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List 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 |