SC194A 1A Synchronous Buck Converter with Integrated Power Devices POWER MANAGEMENT Description Features The SC194A is a synchronous step-down converter with Up to 93% ef ciency integrated power devices. The SC194A is designed for Output current - 1A Input range - 2.7V to 5.5V single-cell Li-Ion battery applications, but can also be used Quiescent current - 17A in xed 3.3V or 5V applications. The switching frequency is Four selectable output voltages nominally set to 1MHz, allowing the use of small inductors Dynamic voltage positioning capability and capacitors. The 1.3A maximum current rating of the Fixed 1MHz frequency or 750kHz to 1.25MHz internal MOSFET switches allows a DC output current of synchronized operation 1A. PSAVE operation to maximize ef ciency at light loads Minimal external components The SC194A has a exible clocking methodology that Fast transient response allows it to be synchronized to an external oscillator or 100% duty cycle in dropout controlled by the internal oscillator. The device can Soft-start operate in either forced PWM mode or in PSAVE mode. If Over-temperature and short-circuit protection PSAVE mode is enabled the part will automatically enter Space-saving lead-free package - MLP-10, 3 x 3mm PFM at light loads to maintain maximum ef ciency across the full load range. Applications For noise sensitive applications, PSAVE mode can be Cell phones disabled by synchronizing to an external oscillator, or Wireless communication chipset power pulling the SYNC/PWM pin high. Shutdown turns off all Personal media player the control circuitry to achieve a typical shutdown current Notebook and sub-notebook computers of 0.1 A. PDAs and mobile communicators WLAN peripherals Typical Application Circuit L1 SC194A V OUT VIN LX V 1.8V IN 4.7 H EN 2.7V to 5.5V 1A SYNC/PWM VOUT C C IN OUT VID0 VID1 PGND 10 F 10 F MODE GND July 05, 2006 1 www.semtech.comSC194A PRELIMINARY POWER MANAGEMENT Absolute Maximum Ratings Exceeding the speci cations below may result in permanent damage to the device or device malfunction. Operation outside of the parameters speci ed in the Electrical Characteristics section is not recommended. Parameter Symbol Maximum Units Input Supply Voltage V -0.3 to 7 V IN Logic Inputs V -0.3 to V +0.3, 7V Max V N IN (SYNC/PWM, EN, MODE, VID0, VID1) Output Voltage V -0.3 to V +0.3, 7V Max V OUT IN LX Voltage V -1 to V +1, 7V Max V LX IN (1) Thermal Impedance Junction to Ambient 40 C/W JA VOUT Short-Circuit to GND t Continuous s SC Operating Ambient Temperature Range T -40 to +85 C A Storage Temperature T -60 to +160 C S Junction Temperature T -40 to +150 C JC Peak IR Re ow Temperature T 260 C LEAD (2) ESD Protection Level V 2kV ESD Note: 1) Calculated from package in still air, mounted to 3 x 4.5, 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards. 2) Tested according to JEDEC standard JESD22-A114-B. Electrical Characteristics Unless otherwise noted: V = 3.6V, EN = V , SYNC/PWM = V , MODE = V , T = -40 to 85C. Typical values are at T = 25C. IN IN IN IN A A Parameter Symbol Conditions Min Typ Max Units Input Voltage Range V 2.7 5.5 V IN VOUT Accuracy V I = 0.5A, T = 25C 1 % OUT OUT A VOUT Temperature Accuracy V I = 0.5A, T = -40 to 85C 0.3 0.7 % OUT(T) OUT A V = 2.7V to 5.5V, V = 1.8V, IN OUT Line Regulation V 0.4 0.65 % OUT LINE I = 0.5A, T = -40 to 85C OUT A Load Regulation (PWM) V I = 0A to 1A, T = -40 to 85C 0.3 0.65 % OUT LOAD OUT A +1.3 +1.6 PSAVE Regulation V SYNC/PWM =GND, C =22 F % OUT PSAVE OUT -0.3 -0.6 P-Channel On Resistance R I = 100mA 0.275 DSP LX N-Channel On Resistance R I = 100mA 0.165 DSN LX Start-Up Time T 5ms START P-Channel Current Limit I 1.33 1.9 2.47 A LIM(P) 2006 Semtech Corp. 2 www.semtech.com