Linear Technology Releases New Energy Monitoring Hot Swap Controller
New Design Enables dual MOSFET's to Drive 100A, for Higher Current Boards
Linear Technology has released the LTC4282, an energy monitoring Hot Swap controller
with dual MOSFET drive to enable 100A and higher current board designs.
The LTC4282 ensures safe board insertion and removal from live 2.9V to 33V backplanes by controlling external Nchannel
MOSFETs to gently power up capacitors, avoiding sparks, connector damage and system glitches.
High current hotpluggable boards utilize parallel MOSFETs to reduce voltage drop,
but all of these MOSFETs require large safe operating area (SOA) to ride through overcurrent faults.
By controlling two matching current limited paths, the LTC4282 halves each path's SOA requirements,
reducing MOSFET costs in high current applications (>50A). Further cost savings are afforded with a
staged start configuration employing a low SOA MOSFET in one path and low Rds(on) MOSFETs in the other path.
The LTC4282 provides a rugged, compact solution for hot plugging and monitoring, especially in high power circuit boards in servers, network routers and switches, and enterprise data storage systems. Sitting at the gateway to board power, the LTC4282's ±0.7% accurate ADC (analog to digital converter) reports board voltage, current, power and energy consumption through an I²C/SMBus digital interface. During overcurrent conditions, the LTC4282 folds back its 2% accurate current limit to maintain constant MOSFET power dissipation for an adjustable timeout period.
Digitally configurable current limit enables dynamic adjustment with load changes and eases selection of low value sense resistors. Minimum and maximum values of the monitored electrical parameters are recorded, with alerts raised when they exceed 8-bit thresholds. Internal EEPROM provides nonvolatile storage for register configuration and fault log data. To prevent catastrophic damage to the board, the MOSFETs are continuously monitored for abnormal conditions such as low gate voltage and drain-to-source shortcircuit or large voltage drop.
Features of the LTC4282 include:
- Enables Safe Board Insertion Into Live Backplane
- 12-/16-bit ADC with ±0.7% Total Unadjusted Error
- I²C/SMBus Intergace to Read Board Voltage, Current, Power & Energy Usage
- Internal EEPROM for Storing Configuration & Fault Log
- Wide Operating Voltage Range: 2.9V to 33V
- High Current Application Features
- Dual MOSFET Gate Drive & Current Sensing
- 12V Gate Drive for Lower MOSFET Rds(on)
- MOSFET Power Limiting with Current Foldback
- Digital Features
- Digitally Adjustable Current Limit & UV/OV/PG Thresholds
- Stores Minimum & Maximum Measurements
- Alerts When Programmed Thresholds Exceeded
- Three General Purpose Input/Outputs
- Continously Monitors MOSFET Health
- Input Undervoltage & Overvoltage Protection
The company's Web site address is www.analog.com.
[Reprinted with kind permission from Linear Technology - Release Date: 1st October, 2015]