SC2620
SC2620 is 30V Step-down Regulator manufactured by SEMTECH.
Description
Dual 2A, 30V Step-down Regulator with Programmable Frequency up to 1.4MHz
Features
Wide Input Voltage Range 2.8V to 30V Up to 1.4MHz/Channel Programmable Switching
Frequency Current-mode Control Out of Phase Switching Reduces Ripple Cycle-by-cycle Current-limiting Independent Shutdown/soft-start Pins Independent Hiccup Overload Protection Channel 1 Power Good Indicator Two 2.3A Integrated Switches Thermal Shutdown Thermally Enhanced SO-16 Lead Free Package Fully WEEE and Ro HS pliant
The SC2620 is a constant frequency dual current-mode switching regulator with integrated 2.3A, 30V switches. Its switching frequency can be programmed up to 1.4MHz per channel. Due to the SC2620’s high frequency operation, small inductors and ceramic capacitors can be used, resulting in very pact power supplies. The two channels of the SC2620 operate at 180° out of phase for reduced input voltage ripples.
Separate soft start/enable pins allow independent control of each channel. Channel 1 power good indicator can be used for output start up sequencing to prevent latch-up. Current-mode PWM control achieves fast transient response with simple loop pensation. Cycle-by-cycle current limiting and hiccup overload protection reduce power dissipation during overload.
Applications
XDSL and Cable Modems Set-top Boxes Point of Load Applications CPE Equipment DSP Power Supplies
Typical Application Circuit
R5 C5 FB1 P1 BOOST1 SS1 22n F R9 46.4k SW1 ROSC 9V-16V VIN C15 R10 10µ F 10 VIN C9 P2 R7 33p F C8 10.5k 4.7n F FB2 BOOST2 GND SW2 D4 1N4148 C4 0.1µ F C16 0.1µ F D2 UPS120 L2 6.8µ H C3 22µ F OUT2 R3 1.2V/2A 2.61k R4 13k D3 C2 1N4148 0.1µ F L1 10µ H D1 UPS120 C1 22µ F R1 30.1k R2 13k
12.7k C6 1.5n F C7 47p F
V IN = 1 2 V
OUT1 3.3V/2A
CH1
PGOOD1 PVIN
CH2
C10 SS2 22n F
CH3
4ms/div CH1 : OUT1 Voltage, 2V/div CH2 : OUT2 Voltage, 1V/div CH3 : SS2 Voltage, 2V/div Figure 1(b). VIN Start-up Transient (IOUT1= 1.5A, IOUT2= 0.8A). Channel 2...
