SEMTECH SC4217

SC4217 Very Low Input /Very Low Dropout 3 Amp Regulator With Enable POWER MANAGEMENT Features Description The SC427 is a 3A, high performance LDO designed for  Input voltage range from .8V to 5.5V use in applications requiring very low input voltage and  Typical 300mV dropout @ 3A very low dropout voltage. It operates with an input volt-  Adjustable output from .24V age as low as .8V and a programmable output voltage  Over-current and over-temperature protection from .24V. The SC427 features ultra- low dropout, ideal  Enable pin for applications where V is very close to V . Addi- OUT IN  0µA shutdown current tionally, the SC427 has an enable pin to further reduce  Full industrial temperature range power dissipation while shut down. The SC427 provides  TO263-5 package, fully WEEE and RoHS compliant excellent regulation over line, load and temperature. Applications The SC427 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 SC4217 EN VO 1 4 EN VO 2 VIN R1 VIN 3 5 C2 GND ADJ C1 R2 0 0 Nov. 7, 20  SC4217 Pin Configuration Ordering Information Device Package ()(2) SC427MTRT TO263-5 TOP VIEW SC427EVB Evaluation Board Notes: ) Available in tape and reel only. A reel contains 800 devices. TAB 2) Device is WEEE and RoHS compliant. 1 2 3 4 5 (TO263-5L) Marking Information 2 SC4217 Recommended Operating Conditions Absolute Maximum Ratings VIN Range…………………………………………… .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) 0s …………………………… 300°C Operating Junction Temperature Range…………… -40 to +25°C ESD Protection Level …………………………………………… 2kV Storage Temperature Range ………………………… -65 to +50°C Thermal Information () Thermal Resistance, junction to case Jθ ……………… 3°C/W JC Thermal Resistance, junction to ambient Jθ …………… 30°C/W JA Other Notes: Tested according to JEDEC standard JESD22-A4-B. ) Calculated from package in still air, mounted to 3” x 4.5”, 4 layer FR4 PCB with thermal vias under the exposed pad per JESD5 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 = .8V to 5.5V, VIN = VO+0.5V, and IO = 0µA to 3A. 2) Values in bold apply over the full operating temperature range. Parameter Symbol Conditions Min Typ Max Units VIN V = 3.3V 0.75 1.75 mA IN Quiescent Current I Q V = 5.5V, V = 0V 0 50 µA IN EN VO V = V + 0.5V -2% +2% IN O () Output Voltage V V O -3% +3% () Line Regulation REG I = 0mA 0.2 0.4 %/V (LINE) O () Load Regulation REG I = 0mA to 3A 0.5 1.0 % (LOAD) O 90 300 I = A O 400 (, 2) Dropout Voltage V mV D 200 400 I = .5A O 500 I = 3A, V = V + 0.5V 300 500 O IN O (, 2) Dropout Voltage V mV D 600 (3) Minimum Load Current I V = V +0.5V  10 μA O IN O Current Limit I 3.3 4.5 6.75 A CL 3 SC4217 Electrical Characteristics (continued) Parameter Symbol Conditions Min Typ Max Units ADJ V = 3.3V, V = V , I = 0mA .227 .252 IN ADJ OUT O () Reference Voltage V .24 V REF 1.215 1.265 (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 = 3.3V .5 10 µA EN EN IN V V = 3.3V 1.6 IH IN Enable Pin Theshold V V V = 3.3V 0.4 IL IN Over Temperature Protection High Trip Level T 60 HI °C Hysteresis T 0 HYST 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 .5% below the value measured at a differential of 0.8V. 3) Required to maintain regulation. Voltage set resistors R and R2 are usually utilized to meet this requirement. Adjustable versions 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 instead. ADJ ADJ 4 SC4217 Pin Descriptions Pin # Pin Name Pin Function Enable input. Pulling this pin below 0.4V turns off the regulator reducing the quiescent current to a franction  EN of its operating value. The device will be enabled if this pin is left open. Connect to V if not being used. IN Input voltage. For regulation at full load, the input to this pin must be between (V +0.5V) and 5.5V. Minimum O 2 VIN V = .8V. A large bulk capacitance should be placed closey to this pin to ensure that the input supply does IN not sag below .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 0µF capactor should be placed directly at this pin. Use external feedback resistors to program the output voltage. See application circuit on page . 5 ADJ V = [(R +R )*.24V]/R . The ADJ pin cannot be tied directly either to VO pin or to GND pin. O 2  2 THERMAL T Thermal pad should be connected to PCB ground plane for thermal and electrical purposes. PAD Block Diagram RSense VO VIN VPump Current Limit Reference VDD ADJ 1.5uA EN 1.24V REF Thermal Shutdown GND VOUT Reverse Voltage VIN Shutdown 5 SC4217 Typical Characteristics ) Unless otherwise noted, typical values are taken under the conditions: T =25°C, V =3.3V, V =2.5V, I =2A, C =C =0.mF(Ceramic)+0mF(Tantalum) AMBIENT IN O O IN OUT Dropout Voltage vs Temperature Dropout Voltage vs Output Current 350 400 300 350 I =3A OUT 250 300 200 250 150 200 100 150 I =1A OUT 25°C 50 100 0 50 0 1 2 3 4 -50 -25 0 25 50 75 100 Output Current (A) Temperature ( °C ) Quiescent Current vs Input Voltage ADJ Pin Leakage Current vs Temperature 90 2.0 V =1.24V ADJ 88 1.5 T = 85 °C AMBIENT 86 1.0 T = 25 °C AMBIENT 84 0.5 82 80 0.0 -50 -25 0 25 50 75 100 3 3.5 4 4.5 5 5.5 6 6.5 Temperature ( °C ) Input Voltage ( V ) Enable Voltage Low vs Temperature Enable Voltage High vs Temperature 1.75 1.50 V =5.5V IN V =5.5V IN 1.50 1.25 1.25 V =3.3V IN V =3.3V IN 1.00 1.00 V =1.8V V =1.8V IN IN 0.75 0.75 0.50 0.50 -50 -25 0 25 50 75 100 -50 -25 0 25 50 75 100 Temperature ( °C ) Temperature ( °C ) 6 SC4217 Typical Characteristics ) Unless otherwise noted, typical values are taken under the conditions: T =25°C, V =3.3V, V =2.5V, I =2A, C =C =0.mF(Ceramic)+0mF(Tantalum) AMBIENT IN O O IN OUT Soft start performance Load transient test Input voltage Output Voltage Output voltage EN pin voltage Output Current 7 SC4217 Applications Information Introduction Thermal Considerations The SC427 is intended for applications where high cur- The power dissipation in the SC427 is approximately rent capability and very low dropout voltage are required. equal to the product of the output current and the It provides a very simple, low cost solution that uses input to output voltage differential: very little PCB real estate. Additional features include an enable pin to allow for a very low power consumption PD |(VINVOUT)uIO standby mode, and a fully adjustable output. The absolute worst-case dissipation is given by: Component Selection PD |(VIN(MAX)VOUT(MIN))uIO(MAX)VIN(MAX)uIQ(MAX) Input Capacitor A minimum of 4.7µF ceramic or tantalum capacitor is For a typical scenario, V = 3.3V ± 5%, V = 2.8V and recommended to be placed directly next to the Vin pin. IN OUT I = .5A, therefore: This allows for the device being some distance from any O bulk capacitance on the rail. Additionally, bulk capaci- tance of about ≥ 0µF may be added closely to the input V = 3.465V, V = 2.744V and I = .75mA, IN(MAX) OUT(MIN) Q(MAX) supply pin of the SC427 to ensure that Vin does not sag, improving load transient response. Thus P = .09W. D(MAX) Output Capacitor Using this figure, and assuming T = 70°C, we can A(MAX) A minimum bulk capacitance of ≥ 0µF, along with a calculate the maximum thermal impedance allowable 0.µF ceramic decoupling capacitor is recommended. to maintain T ≤50°C: J Increasing the bulk capacitance will improve the over- all transient response. The use of multiple lower value (TJ(MAX)TA(MAX)) (15070) RTH(J A)(MAX) 73.4qC/W ceramic capacitors in parallel to achieve the desired bulk PD(MAX) 1.09 capacitance will not cause stability issues. Although designed for use with ceramic output capacitors, the This should be achievable for the TO263-5 package us- SC427 is extremely tolerant of output capacitor ESR ing pcb copper area to aid in conducting the heat away, values and thus will also work comfortably with tantalum such as one square inch of copper connected to the output capacitors. exposed die pad of the device. Internal ground/power planes and air flow will also assist in removing heat. For Noise immunity higher ambient temperatures it may be necessary to In very electrically noisy environments, it is recommended that 0.µF ceramic capacitors be placed from IN to GND use additional copper area. and OUT to GND as close to the device pins as possible. External Voltage Selection Resistors The use of % resistors, and designing for a current flow ≥0µA is recommended to ensure a well regulated output (thus R2 ≤ 50kΩ). Enable Pulling this pin below 0.4V turns the regulator off, reduc- ing the quiescent current to a fraction of its operating value. 8 SC4217 Typical Application Circuits C1 1uF R1 VO=2.5V SC4217 10k 1 4 EN VO VIN=3.3V R2 2 10.2k VIN C2 C3 3 5 GND ADJ 10uF (Tantalum) 0.1uF(Ceramic) C4 C5 R3 GND 10k 10uF (Tantalum) 0.1uF(Ceramic) GND 0 0 AGND PGND 0 Figure 1: Application circuit with 3.3V input and 2.5V output 9 SC4217 Outline Drawing — TO263-5 A E DIMENSIONS E/2 INCHES MILLIMETERS DIM MIN NOM MAX MIN NOM MAX - - 0 L1 A .160 .190 4.06 4.83 - - A1 .000 .010 0.00 0.25 - - b .020 .039 0.51 0.99 c .015 - .029 0.38 - 0.74 D c1 .045 - .065 1.14 - 1.65 D .326 - .380 8.28 - 9.65 H D1 .270 - - 6.86 - - 1 2 3 4 5 E .380 - .420 9.65 - 10.67 - - - - E1 .245 6.22 - - H .575 .625 14.61 15.88 e .067 BSC 1.70 BSC - - L .070 .110 1.78 2.79 - - - - L1 .066 1.68 e N 5 5 - - - - 0 15° 15° b X N aaa B A - - 01 0° 8° 0° 8° aaa .010 0.25 A SEATING PLANE A1 B c1 SIDE VIEW SEE DETAILA PLATED COPPER HEAT SPREADER D1 (L1) c E1 L 01 DETAIL A NOTES: 1. CONTROLLING DIMENSIONS ARE IN INCHES (ANGLES IN DEGREES). 2. DIMENSIONS "D" AND "E" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. 0 SC4217 Land Pattern — TO263-5 H DIMENSIONS DIM INCHES MILLIMETERS G .125 3.17 H .420 10.67 K .350 K 8.89 P .067 1.70 X .042 1.07 Y .140 3.56 Z .615 15.62 Z 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 9302 Phone: (805) 498-2 Fax: (805) 498-3804 www.semtech.com