San Jose, Calif.—Summit Microelectronics touts its SMH4814 as the industry's first programmable dual-feed active OR-ing hot-swap controller. The SMH4814
device can monitor and control two independent -48 volt feeds, allowing for redundant power supply control.
Using the company's GUI-based, non-volatile programming technology, system designers can customize the SMH4814 to address specific power
management and control requirements with a single part number for different platforms.
The SMH4814 provides precise current and voltage control during turn-on and operation. An internal shunt regulator allows compatibility with a wide input voltage range. In place of traditional implementations using (passive) OR-ing diodes, the SMH4814 controls external N-channel field effect transistors (FETs), thus
significantly reducing total system power dissipation.
The SMH4814 features soft-start power-up,
"over-current circuit-breaker" functions and integrated over-voltage and under-voltage monitors. The over-current trip levels, forced shutdown mode, and
over-voltage/under-voltage monitor thresholds are fully programmable. Additionally, a programmable glitch filter is provided on the monitor circuits to prevent
false alarms during transients.
The SMH4814 continuously monitors the incoming feeds and switches to the most negative feed as necessary. In addition, it hot-swaps and sequences up to four independent downstream DC/DC converters with programmable sequence order and delay times. Programming is achieved via an I2C bus and configuration data is stored in EEPROM, of which 256 bytes are available for user data storage. The devices can be programmed during development and then used in a "fixed" configuration or they may be re-programmed in-system via the I2C interface.
The SMH4814, in a 5-by-5, 28-pad QFN and 28-pin SOIC, is priced at $4.18 each (for the commercial temperature range), and at $6.43 (industrial temperature range), both in 1k pieces. The company offers a companion evaluation board with GUI and software to speed designs. It includes all necessary hardware to interface to the parallel or USB
port of a laptop or PC. Once a user completes design and prototyping, the SMH4814 kit automatically
generates a HEX data file that can be transmitted to Summit for review and approval. The design kit software can be downloaded from the company website by clicking here.
Summit Microelectronics, 1-408-436-9890, www.summitmicro.com