LT1949-1 Datasheet | Linear Technology

Final Electrical Specifications LT1949-1 1.1MHz, 1A Switch PWM DC/DC Converter June 2000 DESCRIPTIO Features s s s s s s s s 1A, 0.5Ω, 30V Internal Switch 1.1MHz Fixed Frequency Operation Operates with VIN as Low as 1.5V Low-Battery Detector Stays Active in Shutdown Low VCESAT Switch: 410m V at 800m A Pin-for-Pin patible with the LT1317B Uses Ceramic Capacitors Small 8-Lead MSOP Package U APPLICATIO S s s s s s The LT ®1949-1 is a fixed frequency step-up DC/DC converter with a 1A, 0.5Ω internal switch. Capable of generating 10V at 175m A from a 3.3V input, the LT1949-1 is ideal for generating bias voltages for large screen LCD panels. Constant frequency 1.1MHz operation results in a low noise output that is easy to filter and the 30V switch rating allows output voltage up to 28V using a single inductor. The high switching frequency allows the use of ceramic output capacitors. An external pensation pin gives the user flexibility in optimizing loop pensation, allowing small, low ESR ceramic capacitors to be used at the output. The 8-lead MSOP package ensures a low profile overall solution. The LT1949-1 includes a low-battery detector that stays alive when the device goes into shutdown. Quiescent current in shutdown is 50µA, while operating current is 8m A. , LTC and LT are registered trademarks of Linear Technology Corporation. LCD Bias Supplies GPS Receivers Battery Backup Portable Electronic Equipment Diagnostic Medical Instrumentation TYPICAL APPLICATIO VIN 3.3V C1 3.3µF CERAMIC SHUTDOWN VIN LT1949-1 SHDN VC 84.5k 50p F L1 4.7µH D1 SW VOUT = 10V 80 70 EFFICIENCY (%) VOUT 10V 175m A R1 196k 1% FB GND 3p F 60 50 40 R2 28k 1% C2 3.3µF CERAMIC 30 20 C1, C2: TAIYO YUDEN LMK325BJ335MD D1: MBRM120LT3 L1: SUMIDA CLQ4D10-4R7 1949-1 F01 Figure 1. 3.3V to 10V/175m A DC/DC Converter Figure 2. 3.3V to 10V Converter Efficiency Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility...