SC4217 Very Low Input /Very Low Dropout 3 Amp Regulator With Enable POWER MANAGEMENT Features Description Input voltage range from 1.8V to 5.5V Typical 300mV dropout @ 3A Adjustable output from 1.24V Over-current and over-temperature protection Enable pin 10µA shutdown current Full industrial temperature range TO263-5 package, fully WEEE and RoHS compliant Applications The SC4217 is a 3A, high performance LDO designed for use in applications requiring very low input voltage and very low dropout voltage. It operates with an input voltage as low as 1.8V and a programmable output voltage from 1.24V. The SC4217 features ultra- low dropout, ideal for applications where VOUT is very close to V IN . Additionally, the SC4217 has an enable pin to further reduce power dissipation while shut down. The SC4217 provides excellent regulation over line, load and temperature. The SC4217 is available in a TO263-5 package and is fully WEEE and RoHS compliant. Telecom/networking equipment Motherboards/peripheral cards Industrial equipment Wireless infrastructure Set-top boxes Medical equipment Typical Application Circuit EN 1 SC4217 EN 2 VIN VO VIN 3 GND ADJ VO 4 5 R1 C2 C1 R2 0 Nov. 17, 2011 0 SC4217 Pin Configuration Ordering Information TOP VIEW 2 3 Package SC4217MTRT(1)(2) TO263-5 SC4217EVB Evaluation Board Notes: ) Available in tape and reel only. A reel contains 800 devices. 2) Device is WEEE and RoHS compliant. TAB 1 Device 4 5 (TO263-5L) Marking Information SC4217 Recommended Operating Conditions Absolute Maximum Ratings VIN Range…………………………………………… 1.8V to 5.5V VIN, VO, ADJ to GND ………………………………………………6V Maximum Output Current……………………………………… 3A EN ………………………………………………… -0.3V to VIN+0.3V Operating Ambient Temperature Range ……………… -40 to +85°C Lead Temperature (Soldering) 10s …………………………… 300°C Operating Junction Temperature Range…………… -40 to +125°C ESD Protection Level …………………………………………… 2kV Storage Temperature Range ………………………… -65 to +150°C Thermal Information Thermal Resistance, junction to case Jθ(1)JC……………… 3°C/W Thermal Resistance, junction to ambient JθJA…………… 30°C/W Other Notes: Tested according to JEDEC standard JESD22-A114-B. 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. 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. Electrical Characteristics ) Unless otherwise noted, VEN = VIN. VIN = 1.8V to 5.5V, VIN = VO+0.5V, and IO = 10µA to 3A. 2) Values in bold apply over the full operating temperature range. Parameter Symbol Conditions Min Typ Max Units VIN = 3.3V 0.75 1.75 mA VIN = 5.5V, VEN = 0V 10 50 µA VIN Quiescent Current IQ VO VIN = VO + 0.5V -2% +2% -3% +3% Output Voltage(1) VO Line Regulation(1) REG(LINE) IO = 10mA 0.2 0.4 %/V Load Regulation(1) REG(LOAD) IO = 10mA to 3A 0.5 1.0 % 90 300 IO = 1A Dropout Voltage(1, 2) 400 VD 200 IO = 1.5A Dropout Voltage(1, 2) VD Minimum Load Current(3) IO Current Limit ICL 400 V mV 500 IO = 3A, VIN = VO + 0.5V 300 500 600 VIN = VO +0.5V 3.3 mV 1 10 μA 4.5 6.75 A SC4217 Electrical Characteristics (continued) Parameter Symbol Conditions Min VIN = 3.3V, VADJ = VOUT, IO = 10mA 1.227 Typ Max Units ADJ Reference Voltage(1) VREF Adjust Pin Current(4) IADJ Adjust Pin Threshold (5) 1.215 VADJ = VREF 0.05 V TH(ADJ) 1.24 1.252 V 1.265 80 200 nA 0.16 0.40 V 1.5 10 µA EN Enable Pin Current Enable Pin Theshold IEN VEN = 0V, VIN = 3.3V VIH VIN = 3.3V VIL VIN = 3.3V 1.6 V 0.4 Over Temperature Protection High Trip Level Hysteresis THI 160 THYST 10 °C Notes: ) Low duty cycle pulse testing with Kelvin connections required. 2) Defined as the input to output differential at which the output voltage drops to 1.5% below the value measured at a differential of 0.8V. 3) Required to maintain regulation. Voltage set resistors R1 and R2 are usually utilized to meet this requirement. Adjustable versions only. 4) Guaranteed by design. 5) When VADJ exceeds this threshold, the “Sense Select” switch disconnects the internal feedback chain from the error amplifier and connects VADJ instead. SC4217 Pin Descriptions Pin # Pin Name Pin Function 1 EN Enable input. Pulling this pin below 0.4V turns off the regulator reducing the quiescent current to a franction of its operating value. The device will be enabled if this pin is left open. Connect to VIN if not being used. 2 VIN Input voltage. For regulation at full load, the input to this pin must be between (VO+0.5V) and 5.5V. Minimum VIN = 1.8V. A large bulk capacitance should be placed closey to this pin to ensure that the input supply does not sag below 1.8V. A minimum of 4.7µF ceramic capacitors should be placed directly at this pin. 3 GND Reference ground. The GND pin and the exposed die pad must be connected together at the IC pin. 4 VO The pin is the power output of the device. A minimum of 10µF capactor should be placed directly at this pin. 5 ADJ Use external feedback resistors to program the output voltage. See application circuit on page 1. VO= [(R2+R1)*1.24V]/R2. The ADJ pin cannot be tied directly either to VO pin or to GND pin. T THERMAL PAD Thermal pad should be connected to PCB ground plane for thermal and electrical purposes. Block Diagram RSense VO VIN VPump Current Limit Reference VDD ADJ 1.5uA EN 1.24V REF Thermal Shutdown GND VOUT VIN Reverse Voltage Shutdown SC4217 Typical Characteristics ) Unless otherwise noted, typical values are taken under the conditions: TAMBIENT=25°C, VIN=3.3V, VO=2.5V, IO=2A, CIN=COUT=0.1mF(Ceramic)+10mF(Tantalum) Dropout Voltage vs Temperature Dropout Voltage vs Output Current 350 400 300 350 250 300 200 250 150 200 100 IOUT =3A 150 25°C 50 IOUT =1A 100 0 50 0 1 2 3 -50 4 -25 0 25 50 75 100 Output Current (A) Temperature ( °C ) ADJ Pin Leakage Current vs Temperature Quiescent Current vs Input Voltage 90 2.0 VADJ =1.24V 88 1.5 TAMBIENT = 85 °C 86 1.0 TAMBIENT = 25 °C 84 0.5 82 80 0.0 -50 -25 0 25 50 75 100 3 3.5 Temperature ( °C ) 4 4.5 5 5.5 6 6.5 Input Voltage ( V ) Enable Voltage Low vs Temperature Enable Voltage High vs Temperature 1.50 1.75 V IN =5.5V V IN =5.5V 1.50 1.25 1.25 V IN =3.3V V IN =3.3V 1.00 1.00 V IN =1.8V 0.75 0.50 -50 -25 0 25 50 Temperature ( °C ) V IN =1.8V 0.75 75 100 0.50 -50 -25 0 25 50 75 100 Temperature ( °C ) SC4217 Typical Characteristics ) Unless otherwise noted, typical values are taken under the conditions: TAMBIENT=25°C, VIN=3.3V, VO=2.5V, IO=2A, CIN=COUT=0.1mF(Ceramic)+10mF(Tantalum) Soft start performance Load transient test Input voltage Output Voltage Output voltage EN pin voltage Output Current SC4217 Applications Information Introduction The SC4217 is intended for applications where high current capability and very low dropout voltage are required. It provides a very simple, low cost solution that uses very little pcb real estate. Additional features include an enable pin to allow for a very low power consumption standby mode, and a fully adjustable output. Component Selection Input Capacitor A minimum of 4.7µF ceramic or tantalum capacitor is recommended to be placed directly next to the Vin pin. This allows for the device being some distance from any bulk capacitance on the rail. Additionally, bulk capacitance of about ≥ 10µF may be added closely to the input supply pin of the SC4217 to ensure that Vin does not sag, improving load transient response. Output Capacitor A minimum bulk capacitance of ≥ 10µF, along with a 0.1µF ceramic decoupling capacitor is recommended. Increasing the bulk capacitance will improve the overall transient response. The use of multiple lower value ceramic capacitors in parallel to achieve the desired bulk capacitance will not cause stability issues. Although designed for use with ceramic output capacitors, the SC4217 is extremely tolerant of output capacitor ESR values and thus will also work comfortably with tantalum output capacitors. Noise immunity In very electrically noisy environments, it is recommended that 0.1µF ceramic capacitors be placed from IN to GND and OUT to GND as close to the device pins as possible. Thermal Considerations The power dissipation in the SC4217 is approximately equal to the product of the output current and the input to output voltage differential: PD | (VIN VOUT) u IO The absolute worst-case dissipation is given by: PD | (VIN(MAX) VOUT(MIN)) u IO(MAX) VIN(MAX) u IQ(MAX) For a typical scenario, VIN = 3.3V ± 5%, VOUT = 2.8V and IO = 1.5A, therefore: VIN(MAX) = 3.465V, VOUT(MIN) = 2.744V and IQ(MAX) = 1.75mA, Thus PD(MAX) = 1.09W. Using this figure, and assuming TA(MAX) = 70°C, we can calculate the maximum thermal impedance allowable to maintain TJ ≤150°C: RTH(J A)(MAX) (TJ(MAX) TA(MAX)) PD(MAX) (150 70) 1.09 73.4qC/W This should be achievable for the TO263-5 package using pcb copper area to aid in conducting the heat away, such as one square inch of copper connected to the exposed die pad of the device. Internal ground/power planes and air flow will also assist in removing heat. For higher ambient temperatures it may be necessary to use additional copper area. External Voltage Selection Resistors The use of 1% resistors, and designing for a current flow ≥10µA is recommended to ensure a well regulated output (thus R2 ≤ 50kΩ). Enable Pulling this pin below 0.4V turns the regulator off, reducing the quiescent current to a fraction of its operating value. SC4217 Typical Application Circuits C1 1uF R1 1 VIN=3.3V 2 3 GND C5 10uF (Tantalum) VO=2.5V SC4217 10k EN VO VIN GND ADJ 4 R2 10.2k 5 C4 C2 C3 0.1uF(Ceramic) 10uF (Tantalum) R3 10k 0.1uF(Ceramic) 0 AGND PGND GND 0 0 Figure 1: Application circuit with 3.3V input and 2.5V output SC4217 Outline Drawing — TO263-5 A E E/2 DIM 0 L1 D H 1 2 3 4 5 e bXN aaa B A A A1 b c c1 D D1 E E1 H e L L1 N 0 01 aaa DIMENSIONS INCHES MILLIMETERS MIN NOM MAX MIN NOM MAX .190 4.06 4.83 .010 0.00 0.25 .039 0.51 0.99 .029 0.38 0.74 .065 1.14 1.65 .380 8.28 9.65 6.86 .420 9.65 10.67 6.22 .625 14.61 15.88 .067 BSC 1.70 BSC .070 .110 1.78 2.79 .066 1.68 5 5 15° 15° 0° 8° 0° 8° .010 0.25 .160 .000 .020 .015 .045 .326 .270 .380 .245 .575 A SEATING PLANE A1 B c1 SIDE VIEW SEE DETAIL A PLATED COPPER HEAT SPREADER D1 (L1) c E1 NOTES: 1. CONTROLLING DIMENSIONS ARE IN INCHES (ANGLES IN DEGREES). 2. DIMENSIONS "D" AND "E" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS L DETAIL A 01 OR GATE BURRS. 10 SC4217 Land Pattern — TO263-5 H DIM K Z G H K P X Y Z DIMENSIONS INCHES MILLIMETERS .125 .420 .350 .067 .042 .140 .615 3.17 10.67 8.89 1.70 1.07 3.56 15.62 G Y P X NOTES: 1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. Contact Information Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805) 498-2111 Fax: (805) 498-3804 www.semtech.com 11