Electronic Components Datasheet Search |
|
ISL6566ACR-T Datasheet(PDF) 8 Page - Intersil Corporation |
|
ISL6566ACR-T Datasheet(HTML) 8 Page - Intersil Corporation |
8 / 28 page 8 FN9200.2 July 27, 2005 to smooth the voltage transition during Dynamic VID operations. OFS The OFS pin provides a means to program a dc current for generating an offset voltage across the resistor between FB and VDIFF. The offset current is generated via an external resistor and precision internal voltage references. The polarity of the offset is selected by connecting the resistor to GND or VCC. For no offset, the OFS pin should be left unconnected. OCSET This is the overcurrent set pin. Placing a resistor from OCSET to ICOMP allows a 100 µA current to flow out this pin, producing a voltage reference. Internal circuitry compares the voltage at OCSET to the voltage at ISUM, and if ISUM ever exceeds OCSET, the overcurrent protection activates. ISEN1, ISEN2 and ISEN3 These pins are used for balancing the channel currents by sensing the current through each channel’s lower MOSFET when it is conducting. Connect a resistor between the ISEN1, ISEN2, and ISEN3 pins and their respective phase node. This resistor sets a current proportional to the current in the lower MOSFET during its conduction interval. UGATE1 and UGATE2 Connect these pins to the corresponding upper MOSFET gates. These pins are used to control the upper MOSFETs and are monitored for shoot-through prevention purposes. Maximum individual channel duty cycle is limited to 66%. BOOT1 and BOOT2 These pins provide the bias voltage for the corresponding upper MOSFET drives. Connect these pins to appropriately- chosen external bootstrap capacitors. Internal bootstrap diodes connected to the PVCC pins provide the necessary bootstrap charge. PHASE1 and PHASE2 Connect these pins to the sources of the upper MOSFETs. These pins are the return path for the upper MOSFET drives. LGATE1 and LGATE2 These pins are used to control the lower MOSFETs. Connect these pins to the corresponding lower MOSFETs’ gates. PWM3 Pulse-width modulation output. Connect this pin to the PWM input pin of an Intersil driver IC if 3-phase operation is desired. EN_PH3 This pin has two functions. First, a resistor divider connected to this pin will provide a POR power up synch between the on-chip and external driver. The resistor divider should be designed so that when the POR-trip point of the external driver is reached the voltage on this pin should be 1.220V. The second function of this pin is disabling PWM3 for 2- phase operation. This can be accomplished by connecting this pin to a +5V supply. PGOOD During normal operation PGOOD indicates whether the output voltage is within specified overvoltage and undervoltage limits. If the output voltage exceeds these limits or a reset event occurs (such as an overcurrent event), PGOOD is pulled low. PGOOD is always low prior to the end of soft-start. Operation Multi-Phase Power Conversion Microprocessor load current profiles have changed to the point that the advantages of multi-phase power conversion are impossible to ignore. The technical challenges associated with producing a single-phase converter that is both cost-effective and thermally viable have forced a change to the cost-saving approach of multi-phase. The ISL6566A controller helps simplify implementation by integrating vital functions and requiring minimal external components. The block diagram on page 2 provides a top level view of multi-phase power conversion using the ISL6566A controller. Interleaving The switching of each channel in a multi-phase converter is timed to be symmetrically out of phase with each of the other channels. In a 3-phase converter, each channel switches 1/3 cycle after the previous channel and 1/3 cycle before the following channel. As a result, the three-phase converter has a combined ripple frequency three times greater than the ripple frequency of any one phase. In addition, the peak-to- peak amplitude of the combined inductor currents is reduced in proportion to the number of phases (Equations 1 and 2). FIGURE 1. PWM AND INDUCTOR-CURRENT WAVEFORMS FOR 3-PHASE CONVERTER 1 µs/DIV PWM2, 5V/DIV PWM1, 5V/DIV IL2, 7A/DIV IL1, 7A/DIV IL1 + IL2 + IL3, 7A/DIV IL3, 7A/DIV PWM3, 5V/DIV ISL6566A ISL6566A |
Similar Part No. - ISL6566ACR-T |
|
Similar Description - ISL6566ACR-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 |