CYT 2508 600mA Synchronous Step-Down Regulator Features General Description The CYT2508 is a high efficiency monolithic synchronous buck regulator using a constant frequency, voltage mode architecture. The device is available in fixed output voltage of 1.8V and 1.5V and adjustable output voltage. Supply current during operation is only 20µA and drop to ≤1uA in shutdown. The 2.5V to 5.5V input voltage range makes the CYT2508 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems. Switching frequency is internally set at 1.25MHz, allowing the use of small surface mount inductors and capacitors. The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. The CYT2508 is available in low profile SOT-23-5 package. ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ High Efficiency: Up to 96% Very Low Quiescent Current: Only 20µA During Operation 600mA Output Current 2.5V to 5V Input Voltage Range 1.25MHz Constant Frequency Operation No Schottky Diode Required Low Dropout Operation: 100% Duty Cycle Shutdown Mode draws ≤ 1uA Supply Current Excellent Line and Load Transient Response Overtemperature Protection Available in SOT Package Applications ■ ■ ■ ■ ■ ■ Cellular Phone Personal Information Appliances Wireless and DSL Modems Digital Still Cameras MP3 Players Portable Instruments SOT-23-5 Package ShenZhen CYT IC Design CO ,Ltd 1 CYT 2508 Pin Configuration 1.EN 2.GND 3.SW 4.VIN 5.FB SOT-23-5 Typical Application L1:2.2uH VIN:2.8V to 5V VIN SW CYT2508 EN FB GND VEN＞1V V V CIN:4.7uF VOUT 1.8V/250mA 1.5V/250mA COUT:10uF ShenZhen CYT IC Design CO ,Ltd 2 CYT 2508 Outline Drawing SOT-23-5 DIM A B C D E F H J K N DIMENSIONS INCHES MM MIN MAX MIN MAX 0.110 0.120 2.80 3.05 0.059 0.070 1.50 1.75 0.036 0.051 0.90 1.30 0.014 0.020 0.35 0.50 - 0.037 - 0.95 - 0.075 - 1.90 - 0.006 - 0.15 0.0035 0.008 0.090 0.20 0.102 0.118 2.60 3.00 ShenZhen CYT IC Design CO ,Ltd 3