| Integrated Circuits (ICs) | 5 | Obsolete | |
UCC39123-V to 8-V hot swap controller with circuit breaker and adjustable current monitoring | Integrated Circuits (ICs) | 6 | Active | The UCC3912 family of hot swap power managers provides complete power management, hot swap capability, and circuit breaker functions. The only component required to operate the device, other than supply bypassing, is the fault timing capacitor, CT. All control and housekeeping functions are integrated, and externally programmable. These include the fault current level, maximum output-sourcing current, maximum fault time, and startup delay. In the event of a constant fault, the internal fixed 3% duty cycle ratio limits average output power.
The internal 4-bit DAC allows programming of the fault level current from 0 A to 3 A with 0.25-A resolution. The IMAX control pin sets the maximum sourcing current to 1 A above the fault level when driven low, and to a full 4 A when driven high for applications which require fast output capacitor charging.
When the output current is below the fault level, the output MOSFET is switched on with a nominal on resistance of 0.15. When the output current exceeds the fault level, but is less than the maximum sourcing level, the output remains switched on, but the fault timer starts charging CT. Once CTcharges to a preset threshold, the switch is turned off, and remains off for 30 times the programmed fault time. When the output current reaches the maximum sourcing level, the MOSFET transitions from a switch to a constant current source.
The UCC3912 family is designed for unidirectional current flow, emulating an ideal diode in series with the power switch. This feature is particularly attractive in applications where many devices are powering a common bus, such as with SCSI Termpwr.
The UCC3912 family can be put into sleep mode drawing only 1-µA of supply current. The SHTDWN\ pin has a preset threshold hysteresis which allows the user the ability to set a time delay upon startup to achieve sequencing of power. Other features include an open drain FAULT\ output indicator, thermal shutdown, under voltage lockout, and a low thermal resistance small outline package.
The UCC3912 family of hot swap power managers provides complete power management, hot swap capability, and circuit breaker functions. The only component required to operate the device, other than supply bypassing, is the fault timing capacitor, CT. All control and housekeeping functions are integrated, and externally programmable. These include the fault current level, maximum output-sourcing current, maximum fault time, and startup delay. In the event of a constant fault, the internal fixed 3% duty cycle ratio limits average output power.
The internal 4-bit DAC allows programming of the fault level current from 0 A to 3 A with 0.25-A resolution. The IMAX control pin sets the maximum sourcing current to 1 A above the fault level when driven low, and to a full 4 A when driven high for applications which require fast output capacitor charging.
When the output current is below the fault level, the output MOSFET is switched on with a nominal on resistance of 0.15. When the output current exceeds the fault level, but is less than the maximum sourcing level, the output remains switched on, but the fault timer starts charging CT. Once CTcharges to a preset threshold, the switch is turned off, and remains off for 30 times the programmed fault time. When the output current reaches the maximum sourcing level, the MOSFET transitions from a switch to a constant current source.
The UCC3912 family is designed for unidirectional current flow, emulating an ideal diode in series with the power switch. This feature is particularly attractive in applications where many devices are powering a common bus, such as with SCSI Termpwr.
The UCC3912 family can be put into sleep mode drawing only 1-µA of supply current. The SHTDWN\ pin has a preset threshold hysteresis which allows the user the ability to set a time delay upon startup to achieve sequencing of power. Other features include an open drain FAULT\ output indicator, thermal shutdown, under voltage lockout, and a low thermal resistance small outline package. |
UCC3913Floating negative hot swap controller with commercial temp range with current limiting | Power Management (PMIC) | 3 | Active | The UCCx913 family of negative voltage circuit breakers provides complete power management, hot-swap, and fault handling capability. The device is referenced to the negative input voltage and is driven through an external resistor connected to ground, which is essentially a current drive as opposed to the traditional voltage drive. The on-board 10-V shunt regulator protects the device from excess voltage and serves as a reference for programming the maximum allowable output sourcing current during a fault. In the event of a constant fault, the internal timer limits the on-time from less than 0.1% to a maximum of 3%. The duty cycle modulates depending on the current into the PL pin, which is a function of the voltage across the FET, and limits average power dissipation in the FET. The fault level is fixed at 50 mV across the current-sense resistor to minimize total dropout. The fault current level is set with an external current sense resistor. The maximum allowable sourcing current is programmed with a voltage divider from VDD to generate a fixed voltage on the IMAX pin. The current level, when the output appears as a current source, is equal to VIMAX/RSENSE. If desired, a controlled current startup can be programmed with a capacitor on the IMAX pin.
When the output current is below the fault level, the output device is switched on. When the output current exceeds the fault level, but is less than the maximum sourcing level programmed by the IMAX pin, the output remains switched on, and the fault timer starts charging CT. Once CT charges to 2.5 V, the output device is turned off and performs a retry some time later. When the output current reaches the maximum sourcing current level, the output appears as a current source, limiting the output current to the set value defined by IMAX.
Other features of the UCCx913 family include undervoltage lockout, and 8-pin small outline (SOIC) and dual-in-line (DIP) packages.
The UCCx913 family of negative voltage circuit breakers provides complete power management, hot-swap, and fault handling capability. The device is referenced to the negative input voltage and is driven through an external resistor connected to ground, which is essentially a current drive as opposed to the traditional voltage drive. The on-board 10-V shunt regulator protects the device from excess voltage and serves as a reference for programming the maximum allowable output sourcing current during a fault. In the event of a constant fault, the internal timer limits the on-time from less than 0.1% to a maximum of 3%. The duty cycle modulates depending on the current into the PL pin, which is a function of the voltage across the FET, and limits average power dissipation in the FET. The fault level is fixed at 50 mV across the current-sense resistor to minimize total dropout. The fault current level is set with an external current sense resistor. The maximum allowable sourcing current is programmed with a voltage divider from VDD to generate a fixed voltage on the IMAX pin. The current level, when the output appears as a current source, is equal to VIMAX/RSENSE. If desired, a controlled current startup can be programmed with a capacitor on the IMAX pin.
When the output current is below the fault level, the output device is switched on. When the output current exceeds the fault level, but is less than the maximum sourcing level programmed by the IMAX pin, the output remains switched on, and the fault timer starts charging CT. Once CT charges to 2.5 V, the output device is turned off and performs a retry some time later. When the output current reaches the maximum sourcing current level, the output appears as a current source, limiting the output current to the set value defined by IMAX.
Other features of the UCCx913 family include undervoltage lockout, and 8-pin small outline (SOIC) and dual-in-line (DIP) packages. |
| Hot Swap Controllers | 8 | Active | |
| Integrated Circuits (ICs) | 1 | Active | |
| Hot Swap Controllers | 2 | Active | |
| Hot Swap Controllers | 1 | Obsolete | |
| Integrated Circuits (ICs) | 5 | Obsolete | |
UCC39183-V to 6-V hot swap controller | Power Management (PMIC) | 1 | Unknown | The UCC3918 low on-resistance hot swap power manager provides complete power management, hot swap capability, and circuit breaker functions. The only components needed to operate the device, other than supply bypassing, are a timing capacitor, and two programming resistors. All control and housekeeping functions are integrated, and externally programmable. These include the fault current level, maximum output sourcing current, maximum fault time, and startup delay. In the event of a constant fault, the internal fixed 3%duty cycle ratio limits the average output power. The IFAULT pin allows linear programming of the fault level current from 0 A to 4 A.
Fast overload protection is accomplished by an additional overload comparator. Its threshold is internally set above the maximum sourcing current limit setting. In the event of a short circuit or extreme current condition, this comparator is tripped, shutting down the output. This function is needed since the maximum sourcing current limit loop has a finite bandwidth.
When the output current is below the fault level, the output MOSFET is switched on with a nominal resistance of 0.075. When the output current exceeds the fault level or the maximum sourcing level, the output remains on, but the fault timer starts charging a capacitor connected to the CT pin (CT). Once CTcharges to a preset threshold, the switch is turned off, and remains off for 30 times the programmed fault time. When the output current reaches the maximum sourcing level, the MOSFET transitions from a switch to a constant current source.
The UCC3918 is designed for unidirectional current flow, emulating an ideal diode in series with the power switch. This feature is particularly attractive in applications where many devices are powering a common bus, such as with SCSI termintation power (Termpwr). The UCC3918 can also be put into the sleep mode, drawing only 1 uA of supply current.
Other features include an open-drain fault output indicator, thermal shutdown, undervoltage lockout, 3 V to 6 V operation, and a low thermal resistance small-outline power package.
The UCC3918 low on-resistance hot swap power manager provides complete power management, hot swap capability, and circuit breaker functions. The only components needed to operate the device, other than supply bypassing, are a timing capacitor, and two programming resistors. All control and housekeeping functions are integrated, and externally programmable. These include the fault current level, maximum output sourcing current, maximum fault time, and startup delay. In the event of a constant fault, the internal fixed 3%duty cycle ratio limits the average output power. The IFAULT pin allows linear programming of the fault level current from 0 A to 4 A.
Fast overload protection is accomplished by an additional overload comparator. Its threshold is internally set above the maximum sourcing current limit setting. In the event of a short circuit or extreme current condition, this comparator is tripped, shutting down the output. This function is needed since the maximum sourcing current limit loop has a finite bandwidth.
When the output current is below the fault level, the output MOSFET is switched on with a nominal resistance of 0.075. When the output current exceeds the fault level or the maximum sourcing level, the output remains on, but the fault timer starts charging a capacitor connected to the CT pin (CT). Once CTcharges to a preset threshold, the switch is turned off, and remains off for 30 times the programmed fault time. When the output current reaches the maximum sourcing level, the MOSFET transitions from a switch to a constant current source.
The UCC3918 is designed for unidirectional current flow, emulating an ideal diode in series with the power switch. This feature is particularly attractive in applications where many devices are powering a common bus, such as with SCSI termintation power (Termpwr). The UCC3918 can also be put into the sleep mode, drawing only 1 uA of supply current.
Other features include an open-drain fault output indicator, thermal shutdown, undervoltage lockout, 3 V to 6 V operation, and a low thermal resistance small-outline power package. |
| Integrated Circuits (ICs) | 6 | Obsolete | |
