SC197 3.5MHz, 500mA Synchronous Dual Step-Down DC-DC Regulator POWER MANAGEMENT Features Description Input Voltage 2.9V to 5.5V The SC197 contains two identical high efficiency 500mA Output Voltage 0.8V to 3.3V step-down regulators designed for use in battery- Output current capability 500mA per regulator powered applications. Each regulator includes 15 Efficiency up to 94% programmable output voltage settings that can be Programmable output voltages 15 selected using the four control pins, eliminating the need High light-load efficiency via automatic PSAVE mode for external feedback resistors. The output voltage can be Fast transient response xfi ed to a single setting or dynamically switched between Oscillator frequency 3.5MHz dieff rent levels. Pulling all four control pins low disables 100% duty cycle capability the output. Quiescent current 38A typical per regulator The SC197 operates at a xfi ed 3.5MHz switching frequency Shutdown current 0.1A typical per regulator in normal PWM (Pulse-Width Modulation) mode. A vari- Internal soft-start able frequency PSAVE (Power Save) mode is used to Over-voltage protection optimize efficiency at light loads for each output setting. Current limit and short circuit protection Built-in hysteresis prevents chattering between the two Over-temperature protection modes. Under-voltage lockout Floating control pin protection The SC197 provides several protection features to safe- MLPQ-UT18 2.0 x 3.0 x 0.6 (mm) package guard the device under stressed conditions. These include Lead-free, halogen-free, and RoHS/WEEE compliant short circuit protection, over-temperature protection, Applications under-voltage lockout, and soft-start to control in-rush current. These features, coupled with the small 2.0 x 3.0 x Smart phones and cellular phones 0.6 (mm) package make the SC197 a versatile device ideal MP3/Personal media players for step-down regulation in products needing high effi - Personal navigation devices ciency and a small PCB footprint. Digital cameras Single Li-ion cell or 3 NiMH/NiCd cell devices Devices with 3.3V or 5V internal power rails Typical Application Circuit L XA SC197 1.0H V IN V OUTA INA LXA 2.9V to 5.5V 0.8V to 3.3V C INA OUTA 4.7F C OUTA CTL3A 10F Control Logic CTL2A CTL1A GNDA For Output A CTL0A L XB 1.0H V IN V OUTB INB LXB 2.9V to 5.5V 0.8V to 3.3V C INB OUTB 4.7F C OUTB CTL3B 10F Control Logic CTL2B CTL1B GNDB For Output B CTL0B January 17, 2011 2011 Semtech Corporation 1SC197 Pin Configuration Ordering Information Device Package (1)(2) SC197ULTRT MLPQ-UT18 2 x 3 18 17 16 15 NC SC197EVB Evaluation Board 14 LXA Notes: 1 CTL1A (1) Available in tape and reel only. A reel contains 3,000 devices. 13 GNDA (2) Lead-free packaging only. Device is WEEE and RoHS compliant 2 CTL0A and halogen-free. 12 OUTA 3 OUTB 11 TOP VIEW CTL0B 4 GNDB 10 CTL1B LXB 5 7 8 9 NC 6 MLPQ-UT18 2 x 3, 18 LEAD = 77C/W JA Table 1 Output Voltage Settings CTL3A/B CTL2A/B CTL1A/B CTL0A/B V OUTA/B 0 0 0 0 Shutdown Marking Information 0 0 0 1 0.80 0 0 1 0 1.00 0 0 1 1 1.20 0 1 0 0 1.40 0 1 0 1 1.50 197 0 1 1 0 1.60 0 1 1 1 1.80 yw 1 0 0 0 1.85 1 0 0 1 1.90 xxx 1 0 1 0 2.00 1 0 1 1 2.20 1 1 0 0 2.50 197 = SC197 1 1 0 1 2.80 yw = Date code 1 1 1 0 3.00 xxx = lot number 1 1 1 1 3.30 2 CTL2A INB CTL3A CTL3B INA CTL2B