Electronics News
Archive : 20 March 2008 год
Linear Technology introduces the LTC4443/-1, a synchronous MOSFET driver designed to drive upper and lower power N-Channel MOSFETs in synchronous rectified converter topologies. This driver, combined with power MOSFETs and one of Linear Technology’s many DC/DC controllers, forms a complete synchronous regulator that can be used as a step-down or step-up DC/DC converter. This driver can sink up to 5A and ource up to 2.4A, making it suited for driving high gate capacitance, high current MOSFETs.
The LTC4443/-1 can also drive multiple MOSFETs in parallel for higher current applications. The 12ns rise time and 8ns fall time when driving a 3,000 pF load, minimize switching losses. Adaptive shoot-through protection is integrated to prevent both the upper and lower MOSFETs from conducting simultaneously and to minimize dead time. An integrated bootstrap schottky diode is incorporated. The LTC4443/-1 has a 3-state PWM input for power stage shut-down that is compatible with all multi-phase controllers employing a 3-state output feature. In addition, it has a separate supply for the input logic to match the signal swing of the controller IC and has an undervoltage lockout circuit on both the driver and logic supplies. Furthermore, this part drives both upper and lower MOSFET gates over a range of 6V to 9.5V and operates up to a 38V supply voltage. The -1 version has a higher VCC undervoltage lockout of 6.2V instead of 3.2V, intended to drive standard 5V logic N-Channel MOSFETs.
The LTC4443EDD and LTC4443EDD-1 are offered in a 3mm x 3mm DFN-12 package with prices starting at $1.35 for 1000-piece quantities. The LTC4443IDD and LTC4443IDD-1, tested and guaranteed to operate from -40°C to 85°C operating temperature range are priced at $1.50 in 1000-piece quantities.
The built-in I2C interface supports 400-kbit/s Fast Mode communication, operating as a slave on the I2C bus. Both devices reduce current draw to below 1µA in stand-by mode, to help extend battery life in portable and handheld products. This family is dedicated for applications including Bluetooth headsets and modules, wireless LAN adapters, portable media players, cellular handsets and smart phones, camcorders and digital still cameras. The M24C64 and M24128 are even specified to operate with power supplies as low as 1.7V. Other features include: a write-control input, byte- and page-write modes, random and sequential read modes, self-timed programming cycle and automatic address incrementing. Device lifetime is greater than one million write cycles, and data retention more than 40 years. All of the devices in the I2C and SPI families, in the MLP-8 package and spanning densities from 2 Kbit to 128 Kbit, are available now. The M24C64-FMB6TG is priced at $0.24 in quantities of 1000 units, the M24128-FMB6TG at $0.34, and the M95128-RMB6TG at $0.48 in the same quantities.