LTC3672B-1 APPLICATIONS INFORMATIONTable 1. Recommended Inductors for the Buck RegulatorINDUCTOR TYPELMAX IDCMAX DCRSIZE IN mmMANUFACTURER(μH)(A)( Ω )(L × W × H) DB318C 4.7 1.07 0.1 3.8 × 3.8 × 1.8 Toko 3.3 1.2 0.07 3.8 × 3.8 × 1.8 www.toko.com D312C 4.7 0.79 0.24 3.6 × 3.6 × 1.2 3.3 0.9 0.2 3.6 × 3.6 × 1.2 DE2812C 4.7 1.15 0.13* 3 × 2.8 × 1.2 3.3 1.37 0.105* 3 × 2.8 × 1.2 CDRH3D16 4.7 0.9 0.11 4 × 4 × 1.8 Sumida 3.3 1.1 0.085 4 × 4 × 1.8 www.sumida.com CDRH2D11 4.7 0.5 0.17 3.2 × 3.2 × 1.2 3.3 0.6 0.123 3.2 × 3.2 × 1.2 CLS4D09 4.7 0.75 0.19 4.9 × 4.9 × 1 SD3118 4.7 1.3 0.162 3.1 × 3.1 × 1.8 Cooper 3.3 1.59 0.113 3.1 × 3.1 × 1.8 www.cooperet.com SD3112 4.7 0.8 0.246 3.1 × 3.1 × 1.2 3.3 0.97 0.165 3.1 × 3.1 × 1.2 SD12 4.7 1.29 0.117* 5.2 × 5.2 × 1.2 3.3 1.42 0.104* 5.2 × 5.2 × 1.2 SD10 4.7 1.08 0.153* 5.2 × 5.2 × 1 3.3 1.31 0.108* 5.2 × 5.2 × 1 LPS3015 4.7 1.1 0.2 3 × 3 × 1.5 Coil Craft 3.3 1.3 0.13 3 × 3 × 1.5 www.coilcraft.com * = Typical DCR INPUT/OUTPUT CAPACITOR SELECTION Consult with capacitor manufacturers for detailed infor- mation on their selection and specifi cations of ceramic Low ESR (equivalent series resistance) ceramic capacitors capacitors. Many manufacturers now offer very thin (<1mm should be used to bypass the following pins to ground: tall) ceramic capacitors ideal for use in height-restricted VIN, VIN1, the buck output, LDO1, and LDO2. Only X5R designs. Table 2 shows a list of several ceramic capacitor or X7R ceramic capacitors should be used because they manufacturers. retain their capacitance over wider voltage and temperature ranges than other ceramic types. A 10μF output capaci- Table 2. Ceramic Capacitor Manufacturers tor is suffi cient for the buck regulator output. For good AVX www.avxcorp.com transient response and stability the output capacitor for Murata www.murata.com the buck regulator should retain at least 4μF of capaci- Taiyo Yuden www.t-yuden.com tance over operating temperature and bias voltage. The Vishay Siliconix www.vishay.com VIN pin should be bypassed with a 2.2μF capacitor. The TDK www.tdk.com LDO1 and LDO2 output pins should be bypassed with a 1μF capacitor or greater. VIN1 should be bypassed with a 1μF capacitor, which may be omitted if VIN1 is tied to the buck regulator’s output capacitor. 3672B1f 9