SEMTECH SC4215

SC4215 Very Low Input /Very Low Dropout 2 Amp Regulator With Enable POWER MANAGEMENT Features Description  Input Voltage as low as .6V The SC425 is a high performance positive voltage regula-  500mV dropout @ 2A tor designed for use in applications requiring very low  Adjustable output from 0.8V input voltage and very low dropout voltage at up to 2  Over current and over temperature protection amperes. It operates with a Vin as low as .6V, with output  Enable pin voltage programmable as low as 0.8V. The SC425 features  0µA quiescent current in shutdown ultra low dropout, ideal for applications where Vout is very  Full industrial temperature range close to Vin. Additionally, the SC425 has an enable pin to  Available in SOIC-8-EDP Pb-Free product. RoHS/WEEE further reduce power dissipation while shut down. The and Halogen Free compliant SC425 provides excellent regulation over variations in line, load and temperature. Applications The SC425 is available in the SOIC-8-EDP (Exposed Die Pad) package. The output voltage can be set via an exter-  Telecom/Networking cards nal divider or to fixed settings of 0.8V and 2.5V depending  Motherboards/Peripheral cards on how the ADJ pin is configured.  Industrial applications  Wireless infrastructure  Set top boxes  Medical equipment  Notebook computers  Battery powered systems Typical Application Circuit October 8, 2009 © 2009 Semtech Corporation  SC4215 Pin Configuration Ordering Information Device Package ()(2) SC425ISTRT SOIC-8-EDP SC425IEVB Evaluation Board Notes: () Available in tape and reel only. A reel contains 2,500 devices. (2) Available in Pb-Free product only. RoHS/WEEE and Halogen Free compliant. Marking Information 2 SC4215 Absolute Maximum Ratings Recommended Operating Conditions VIN, EN, VO, ADJ to GND (V) . . . . . . . . . . . . . . . . . -0. to +7.0 VIN (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 < V < 5.5 IN Power Dissipation . . . . . . . . . . . . . . . . . . . . . Internally Limited Ambient Temperature Range (°C) . . . . . . . . . -40 < T < +85 A () ESD Protection Level (kV) . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Junction Temperature Range (°C) . . . . . . . . . -40 < T < +25 J Maximum Output Current (A) . . . . . . . . . . . . . . . . . . . . . . . . .2 Thermal Information (2) Thermal Resistance, Junction to Ambient (°C/W) . . . . 6 (2) Thermal Resistance, Junction to Case (°C/W) . . . . . . . . 5.5 Maximum Junction Temperature (°C) . . . . . . . . . . . . . .+50 Storage Temperature Range (°C) . . . . . . . . . . . . -65 to +50 Peak IR Reflow Temperature (0s to 0s) (°C) . . . . . . +260 Exceeding the above specifications may result in permanent damage to the device or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not recommended. NOTES: () Tested according to JEDEC standard JESD22-A4-B. (2) Calculated from package in still air, mounted to ” x 4.5”, 4 layer FR4 PCB with thermal vias under the exposed pad per JESD5 standards. Electrical Characteristics Unless specified: V = V , V = .6V to 5.5V, I = 0µA to 2A, T = 25° C. EN IN IN O A Values in bold apply over the full operating temperature range. Parameter Symbol Conditions Min Typ Max Units VIN V = .V, I = 0A 0.75 1.75 mA IN O Quiescent Current I Q V = 5.5V, V =0V 0 50 µA IN EN VO () Output Voltage V = V + 0.5V, I = 0mA -2% +2% IN O O V V V O O (Fixed Voltage, V = 0) .60V ≤ V ≤ 5.5V, I = 0mA -3% +3% ADJ IN O () Line Regulation REG I =0mA 0.2 0.4 %/V (LINE) O () Load Regulation REG I =0mA to 2A 0.5 1.0 % (LOAD) O  SC4215 Electrical Characteristics (continued) Parameter Symbol Conditions Min Typ Max Units 90 00 I =A O 400 200 400 ()(2) Dropout Voltage V I =.5A mV DO O 500 V =V + 0.5V 00 500 IN O I = 2A O V =V + 0.6V 600 IN O ()(4) Minimum Load Current I V =V + 0.5V  10 µA O IN O (4) Current Limit I 2.2  4.5 A CL ADJ 0.792 0.808 () Reference Voltage V V = .V, V = V , I =0mA 0.8 V REF IN FB OUT O 0.784 0.816 (4) Adjust Pin Current I V = V 80 200 nA ADJ ADJ REF (5) Adjust Pin Threshold V 0.05 0.6 0.40 V TH(ADJ) EN Enable Pin Current I V = 0V, V =.V .5 10 µA EN EN IN V 1.6 IH Enable Pin Threshold V =.V V IN V 0.4 IL Over Temperature Protection O High Trip Level T 60 C HI O Hysteresis T 0 C HYST Notes: () Low duty cycle pulse testing with Kelvin connections required. (2) V = V -V when V decreases by .5% of its nominal output voltage. DO IN O O () Required to maintain regulation. Voltage set resistors R and R2 are usually utilized to meet this requirement. Adjustable mode only. (4) Guaranteed by design. (5) When V exceeds this threshold, the “Sense Select” switch disconnects the internal feedback chain from the error amplifier and connects V ADJ ADJ instead. 4 SC4215 Typical Characteristics 5 SC4215 Pin Descriptions Pin # Pin Name Pin Function Enable Input. Pulling this pin below 0.4V turns the regulator off, reducing the quiescent current to 2 EN a fraction of its operating value. The device will be enabled if this pin is left open. Connect to VIN if not being used. Input voltage. For regulation at full load, the input to this pin must be between (VO+ 0.5V) and 5.5V. Minimum VIN = .6V. A large bulk capacitance should be placed closely to this pin to ensure  VIN that the input supply does not sag below .6V. Also a minimum of 4.7uF ceramic capacitor should be placed directly at this pin. The pin is the power output of the device. A minimum of 0uF capacitor should be placed directly 6 VO at this pin. When this pin is grounded, an internal resistor divider sets the output voltage to 2.5V. If connected 7 ADJ to the Vo pin, the output voltage will be set at 0.8V. If external feedback resistors are used, the output voltage will be determined by the resistor ratio (See Application Circuits on page ): Reference ground. The GND pin and the exposed die pad must be connected together at the IC 8 GND pin. , 4, 5 NC No Connection. THERMAL PAD Pad for heatsinking purposes. Connect to ground plane using multiple vias. Block Diagram 6 SC4215 Applications Information (continued) Introduction ≤50kΩ). A suitable value for R2 can be chosen in the range The SC425 is intended for applications where high of kΩ to 50kΩ. R can then be calculated from. current capability and very low dropout voltage are ((V V −−V V )) O O R RE EFF required. It provides a very simple, low cost solution that R R ==R R ⋅⋅ 11 22 V V R RE EFF uses very little PCB real estate. Additional features include an enable pin to allow for a very low power consumption Enable: Pulling this pin below 0.4V turns the regulator off, standby mode, and a fully adjustable output. reducing the quiescent current to a fraction of its operat- ing value. A pull up resistor up to 400kOhms should be Component Selection connected from this pin to the VIN pin in applications Input capacitor: A large bulk capacitance ≥ 0µF/A where supply voltages of Vin < .9V are required. For (output load) should be closely placed to the input supply applications with higher voltages than .9V, EN pin could pin of the SC425 to ensure that Vin does not sag below be left open or connected to VIN. .4V. Also a minimum of 4.7µF ceramic capacitor is recom- mended to be placed directly next to the Vin pin. This Thermal Considerations allows for the device being some distance from any bulk The power dissipation in the SC425 is given by: capacitance on the rail. Additionally, input droop due to P P ≈≈II ⋅⋅((V V −−V V )) D D O O IIN N O O load transients is reduced, improving load transient response. Additional capacitance may be added if required The allowable power dissipation will be dependant on the by the application. thermal impedance achieved in the application. The derat- ing curve below is valid for the thermal impedance speci- Output capacitor: A minimum bulk capacitance of ≥ fied in the Thermal Information section on page . 0µF/A (output load), along with a 0.µF ceramic decou- pling capacitor is recommended. Increasing the bulk capacitance will improve the overall transient response. The use of multiple lower value ceramic capacitors in par- allel to achieve the desired bulk capacitance will not cause stability issues. Although designed for use with ceramic output capacitors, the SC425 is extremely tolerant of output capacitor ESR values and thus will also work com- fortably with tantalum output capacitors. Noise immunity: In very electrically noisy environments, it is recommended that 0.µF ceramic capacitors be placed from IN to GND and OUT to GND as close to the device pins as possible. Internal voltage selection: By connecting the ADJ pin to GND, an internal resistor divider will regulate the output voltage to 2.5V. If the ADJ pin is connected directly to the VO pin, the output voltage will be regulated to the 0.8V internal reference. External voltage selection resistors: The use of % resistors, and designing for a current flow ≥ 0µA is rec- ommended to ensure a well regulated output (thus R2 7 SC4215 Outline Drawing — SOIC-8-EDP-3 8 SC4215 Land Pattern — SOIC-8-EDP-3 Contact Information Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 902 Phone: (805) 498-2 Fax: (805) 498-804 www.semtech.com 9