Milpitas, Calif.—Linear Technology's LTC4242, a narrow, dual-slot PCI Express hot swap controller for mid-range networking or storage servers and embedded applications, eliminates complex software interfaces, yet provides a rugged and compact solution for independently controlling the main supplies (12 and 3.3 volts) and the auxiliary 3.3-volt supply on two slots.
Each supply is continuously monitored for under-voltage and over-current faults. The 12-volt supply inputs are protected up to 20 volts. Together with analog current limit amplifiers, electronic circuit breakers with adjustable response time will provide dual level over-current protection. Control for the auxiliary supplies is completely independent with separate ON and FAULT pins. The internal 3.3V AUX MOSFET has an on-resistance of 250 milliohms which, together with the exposed backside metal on the device's QFN package and thermal shutdown protection, minimizes heat in the device. A separate VCC pin allows the part to power up without the main supplies being present and the ability to ride out glitches in the auxiliary supply.
The device's 5-by-7 mm QFN package is narrow enough to fit between the PCI Express connectors if needed for board space optimization. Optionally, a 36-pin SSOP is available for narrow applications, requiring less than 8 mm including the landing area for the pins. The controller offers independent control of the main and auxiliary supplies for each port, separate FAULT outputs for main and auxiliary supplies, power-good outputs for each slot and board-present inputs for each slot.
Click here for the product datasheet. The LTC4242, specified over the commercial and industrial temperature ranges, is available from stock, and priced beginning at $3.30 each in 1,000 piece quantities. For more sophisticated monitoring, Linear Technology also offers the single-slot LTC4245 which includes an integrated ADC and I2C interface for high-end PCI Express applications.
Linear Technology, 1-800-4LINEAR, www.linear.com