Datasheet SiC931 (Vishay) - 7
| Fabricante | Vishay |
| Descripción | 4.5 V to 18 V Input, 20 A MicroBRICK DC/DC Regulator Module |
| Páginas / Página | 22 / 7 — SiC931. Mode Setting, Over Current Protection, Switching. Frequency, and … |
| Formato / tamaño de archivo | PDF / 3.6 Mb |
| Idioma del documento | Inglés |
SiC931. Mode Setting, Over Current Protection, Switching. Frequency, and Soft Start Selection
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SiC931
www.vishay.com Vishay Siliconix
Mode Setting, Over Current Protection, Switching
to enable or disable the light load mode. Two MODE pins,
Frequency, and Soft Start Selection
MODE1 and MODE2, are user programmable by connecting The SiC931 has a low pin count, minimal external a resistor from MODEx to VDD or AGND, allowing the user to components, and offers the user flexibility to choose soft choose various operating modes. This is best explained in start times, current limit settings, switching frequencies and the tables below.
TABLE 1 - MODE1 CONFIGURATION SETTINGS OPERATION CONNECTION fSWITCH (kHz) RMODE1 (k )
600 51 1000 100 Skip To AGND 1500 200 2000 499 600 51 1000 100 Forced CCM To VDD 1500 200 2000 499
TABLE 2 - MODE2 CONFIGURATION SETTINGS SOFT-START TIME CONNECTION ILIMIT (%) RMODE2 (k )
30 51 54 100 3 ms To AGND 78 200 100 (32 A) 499 30 51 54 100 6 ms To VDD 78 200 100 (32 A) 499
OUTPUT MONITORING AND PROTECTION FEATURES Output Over Current Protection (OCP) Output Undervoltage Protection (UVP)
SiC931 has pulse-by-pulse over current limit control. The UVP is implemented by monitoring the FB pin. If the voltage inductor current is monitored during low side MOSFET level at FB drops below 0.12 V for more than 25 μs, a UVP conduction time through RDS(on) sensing. After a pre-defined event is recognized and both high side and low side blanking time, the inductor current is compared with an MOSFETs are turned off. After a duration equivalent to 20 internal OCP threshold. If inductor current is higher than soft start periods, the IC attempts to re-start. If the fault OCP threshold, high side MOSFET is kept off until the condition still exists, the above cycle will be repeated. inductor current falls below OCP threshold. UVP is active after the completion of soft start sequence. OCP is enabled immediately after VDD passes UVLO rising
Output Overvoltage Protection (OVP)
threshold. OVP is implemented by monitoring the FB pin. If the voltage level at FB rising above 0.72 V, a OVP event is recognized and both high side and low side MOSFETs are turned off. OCPthreshold Normal operation is resumed once FB voltage drop below 0.68 V. Iload I OVP is active after VDD passes UVLO rising threshold. inductor
Over-Temperature Protection (OTP)
OTP is implemented by monitoring the junction GH temperature. If the junction temperature rises above 150 °C, a OTP event is recognized and both high side and low
Fig. 8 - Over-Current Protection Illustration
MOSFETs are turned off. After the junction temperature falls below 115 °C (35 °C hysteresis), the device restarts by initiating a soft start sequence. S23-0880-Rev. G, 23-Oct-2023
7
Document Number: 79602 For technical questions, contact: powerictechsupport@vishay.com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
www.vishay.com Vishay Siliconix
Mode Setting, Over Current Protection, Switching
to enable or disable the light load mode. Two MODE pins,
Frequency, and Soft Start Selection
MODE1 and MODE2, are user programmable by connecting The SiC931 has a low pin count, minimal external a resistor from MODEx to VDD or AGND, allowing the user to components, and offers the user flexibility to choose soft choose various operating modes. This is best explained in start times, current limit settings, switching frequencies and the tables below.
TABLE 1 - MODE1 CONFIGURATION SETTINGS OPERATION CONNECTION fSWITCH (kHz) RMODE1 (k )
600 51 1000 100 Skip To AGND 1500 200 2000 499 600 51 1000 100 Forced CCM To VDD 1500 200 2000 499
TABLE 2 - MODE2 CONFIGURATION SETTINGS SOFT-START TIME CONNECTION ILIMIT (%) RMODE2 (k )
30 51 54 100 3 ms To AGND 78 200 100 (32 A) 499 30 51 54 100 6 ms To VDD 78 200 100 (32 A) 499
OUTPUT MONITORING AND PROTECTION FEATURES Output Over Current Protection (OCP) Output Undervoltage Protection (UVP)
SiC931 has pulse-by-pulse over current limit control. The UVP is implemented by monitoring the FB pin. If the voltage inductor current is monitored during low side MOSFET level at FB drops below 0.12 V for more than 25 μs, a UVP conduction time through RDS(on) sensing. After a pre-defined event is recognized and both high side and low side blanking time, the inductor current is compared with an MOSFETs are turned off. After a duration equivalent to 20 internal OCP threshold. If inductor current is higher than soft start periods, the IC attempts to re-start. If the fault OCP threshold, high side MOSFET is kept off until the condition still exists, the above cycle will be repeated. inductor current falls below OCP threshold. UVP is active after the completion of soft start sequence. OCP is enabled immediately after VDD passes UVLO rising
Output Overvoltage Protection (OVP)
threshold. OVP is implemented by monitoring the FB pin. If the voltage level at FB rising above 0.72 V, a OVP event is recognized and both high side and low side MOSFETs are turned off. OCPthreshold Normal operation is resumed once FB voltage drop below 0.68 V. Iload I OVP is active after VDD passes UVLO rising threshold. inductor
Over-Temperature Protection (OTP)
OTP is implemented by monitoring the junction GH temperature. If the junction temperature rises above 150 °C, a OTP event is recognized and both high side and low
Fig. 8 - Over-Current Protection Illustration
MOSFETs are turned off. After the junction temperature falls below 115 °C (35 °C hysteresis), the device restarts by initiating a soft start sequence. S23-0880-Rev. G, 23-Oct-2023
7
Document Number: 79602 For technical questions, contact: powerictechsupport@vishay.com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000