Datasheet SiC450, SiC451, SiC453 (Vishay) - 10

SiC450, SiC451, SiC453
www.vishay.com Vishay Siliconix
VOUT RELATED WARNINGS AND VOLTAGE LEVEL FREQUENCY SETTINGS FAULTS RT RESISTOR (k
Ω
) FREQUENCY (kHz)
POWER_GOOD_ON 90 % VOUT 0.845 300 POWER_GOOD_OFF 85 % VOUT 1.30 400 VOUT_OV_FAULT_LIMIT 115 % VOUT 1.78 500 VOUT_OV_WARN_LIMIT 110 % VOUT 2.32 550 VOUT_UV_WARN_LIMIT 90 % VOUT 2.87 600 VOUT_UV_FAULT_LIMIT 80 % VOUT 3.48 650 VOUT_MARGIN_LOW 95 % VOUT 4.12 700 VOUT_MARGIN_HIGH 105 % VOUT 4.75 750
RT/SYNC PIN and Mode of Switching Configuration
5.49 800 The SiC45x has an RT / SYNC pin. This pin can be used to 6.19 850 set the switching frequency and to send or receive a clock 6.98 900 signal for synchronization between a master and slave. 7.87 950 SiC45x will inject less than 1 mA DC current across the 8.87 1000 RT/SYNC pin to the ground during initial power up process, 10 1250 and connecting a resistor from the RT/SYNC pin to ground 11 1500 will be used to set the switching frequency according to the table listed below. The following table shows the supported SiC45x supports four modes of switching configuration, frequency settings by the RT resistor value. Please do not including standalone mode, master mode, slave mode in leave the setting resistor open or short, or contact Vishay for phase, and slave mode 180° out of phase. The master mode technical support. The frequency set by the external resistor is default one of switching configuration and user can can be overridden by a PMBus command with resolution override it to be either standalone mode, slave mode in 50 kHz (see PMBus command table). phase, or slave mode 180° out of phase by PMBus command INTERLEAVE (see PMBus command table). The following table introduces four modes of switching configuration, recommended RT/SYNC pin connections, and content of related PMBus command INTERLEAVE.
MODE OF SWITCHING CONFIGURATION, PIN CONNECTION, AND INTERLEAVE PMBus SWITCHING FREQUENCY AND RECOMMENDED SWITCHING INTERLEAVE MODE TYPE MODE DESCRIPTION RT/SYNC PIN CONNECTION PHASE COMMAND
Cross a resistor RRT from RT / SYNC pin to ground. During power up, less than 1 mA DC current will be injected into resistor R Standalone Chip works individually RT to determine default switching frequency. The Self determined 0x0000 default switching frequency can be overridden by PMBus command. After power up, RT / SYNC pin is released and connected to ground via RRT. Chip works as a master Cross a resistor RRT from RT / SYNC pin to ground. During chip outputting a clock power up, less than 1 mA DC current will be injected into signal in phase with its resistor RRT to determine default switching frequency. The Master switching to drive an default switching frequency can be overridden by PMBus Self determined 0x0100 external slave chip’s command. After power up, RT / SYNC pin outputs a 50 % switching frequency and duty cycle pulse signal toggling between 0 and VDD, which phase is in phase with the chip’s switching node. Cross a resistor RRT from RT / SYNC pin to ground. During power up, less than 1 mA DC current will be injected into resistor R Chip works as a slave RT to determine default switching frequency. The default switching frequency can be overridden by PMBus In phase with the chip receiving an external command. When there is an external clock signal external clock, or clock signal and Slave in phase presented at the RT / SYNC pin, the switching frequency self determined 0x0120 synchronize its switching will be overridden and the chip’s switching node is in when individually in phase with the clock phase with the external clock signal. If the external clock works signal signal comes from a SiC45x working in master mode switching configuration, the resistor RRT shall be same to the RRT used by the master chip. S21-0213-Rev. B, 08-Mar-2021
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