SC2621A
SC2621A is Voltage Mode PWM Controller manufactured by SEMTECH.
Description
The SC2621A provides the control and protection Features necessary for a synchronous buck converter and a linear regulator in high performance graphic card applications. The SC2621A is designed to directly drive the top and bottom MOSFETs of the buck converter. It uses an internal 8.2V supply as the gate drive voltage for minimum driver power loss and MOSFET switching loss. It allows the converter to operate with 4V to 25V power rail and as low as 0.5V output. The SC2621A is capable to drive a N-type MOSFET in a linear regulator with as low as 0.5V output. The SC2621A Features soft-start, supply power under voltage lockout, and hiccup mode over current protection. The SC2621A monitors the output current by using the Rdson of the bottom MOSFET in the buck converter that eliminates the need for a current sensing resistor. The SC2621A is offered in SOIC-14 package.
Features u u u u u u u u u
4V to 25V power rails Internal LDO for optimum gate drive voltage 1.5A gate drive current Adaptive non-overlapping gate drives provide shoot-through protection for MOSFETs Programmable output voltages Internal soft start for both outputs Power rail under voltage lockout Hiccup mode short circuit protection SOIC-14 package, fully Ro HS and WEEE pliant
Applications u Graphics processor power supplies on PCI-Express platform u Embedded, low cost, high efficiency converters u Point of load power supplies
Typical Application Circuit
12V IN
+
1.5V OUT
U2 1 B ST OCS P FB LDOG LDFB GND S C2 621A DH PN GND DL DRV NC V CC 14 13 12 11 10 9 8 + 1 2
3.3V IN
2 3 4
2.5V OUT
5 6 7 +
February 21, 2007
.semtech.
POWER MANAGEMENT .. Absolute Maximum Ratings
Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied.
Parameter Input Supply Voltage BST to GND BST to PN PN to GND PN to GND Negative Pulse (tpulse <...
