Electronic Components Datasheet Search |
|
ACT8798QLGHW-T Datasheet(PDF) 11 Page - Active-Semi, Inc |
|
ACT8798QLGHW-T Datasheet(HTML) 11 Page - Active-Semi, Inc |
11 / 34 page SYSTEM MANAGEMENT ACT8798 Rev0, 10-Oct-08 Innovative Power TM - 11 - www.active-semi.com Copyright © 2008 Active-Semi, Inc. ActivePMU TM is a trademark of Active-Semi. I 2CTM is a trademark of Philips Electronics. nMSTR Enable Input In most applications, connect nMSTR to an active low, momentary push-button switch to utilize the ACT8798's closed-loop enable/disable functionality. If a momentary-on switch is not used, drive nMSTR to GA or to a logic low to initiate a startup se- quence. Enable/Disable Inputs The ACT8798 provides two manual enable/disable inputs, PWRHLD and ON3. PWRHLD is the master enable input. When driven high, PWRHLD enables REG1, REG2, and REG4, and also activates the enable/disable control logic for the other regulators. ON3 is the enable input for REG3, and is active when either of the following conditions exists: 1) nMSTR is asserted low, or 2) PWRHLD is asserted high. Power-On Reset Output The ACT8798 integrates a 260ms power-on reset generator, reducing system size and cost. nRSTO is an open-drain output. Connect a 10kΩ or greater pull-up resistor from nRSTO to an appropriate volt- age supply. nRSTO asserts low upon startup and remains low until the reset-timeout period expires, at which point nRSTO goes high-Z. nIRQ Output Figure 2 shows two simple circuits that can be used to generate nIRQ, a processor interrupt signal, which can be used as part of the ACT8798’s push- button control logic. This signal is typically used to drive the interrupt input of the system processor, and is useful in a variety of software-controlled en- able/disable control routines. Figure 2A provides an active-low, open-collector push-button status output that sinks current when nMSTR is driven to a logic- low. Figure 2B provides an active-high, open- collector push-button status output that sources current when nMSTR is driven to a logic-low. Thermal Shutdown The ACT8798 integrates thermal shutdown protec- tion circuitry to prevent damage resulting from ex- cessive thermal stress, as may be encountered un- der fault conditions. This circuitry disables all regu- lators if the ACT8798 die temperature exceeds 160°C, and prevents the regulators from being en- abled until the IC temperature drops by 20°C (typ). FUNCTIONAL DESCRIPTION (CONT’D) Figure 2: Simple Circuits ACT8798 PB PB nMSTR ACT8798 100k 100k nIRQ OUT2 VCC CPU 500k OUT2 VCC nIRQ 100k 100k INL (A) (B) |
Similar Part No. - ACT8798QLGHW-T |
|
Similar Description - ACT8798QLGHW-T |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | 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 |