SC4215J Very Low Input /Very Low Dropout 2 Amp Regulator With Soft-Start POWER MANAGEMENT Features Description Input Voltage as Low as 1.4V 400mV Dropout @ 2A Adjustable Output from 0.5V 1ms Internal Soft-Start Minimizes Inrush Current Over Current and Over Temperature Protection Enable Function Option 10µA Quiescent Current in Shutdown Reverse Blocking from Output to Input Full Industrial Temperature Range Fully WEEE and RoHS Compliant Applications The SC4215J is a high performance positive voltage regulator designed for use in applications requiring very low input voltage and very low dropout voltage at up to 2 amperes. It operates with a Vin as low as 1.4V, with output voltage programmable as low as 0.5V. The SC4215J features ultra low dropout, ideal for applications where Vout is very close to Vin. Additionally, the SC4215J has an enable pin to further reduce power dissipation while shut down. The SC4215J provides excellent regulation over variations in line, load and temperature. The SC4215J is available in the SOIC-8-EDP (Exposed Die Pad) package. The output voltage can be set via an external divider or to a fixed setting of 0.5V depending upon how the FB pin is configured. Telecom and Networking Cards Motherboards and Peripheral Cards Industrial Applications Wireless Infrastructure Medical Equipment Typical Application Circuit SC4215J SC4215J 0 .5 R 1 R2 R1 0 .5 V C1 C2 R2 C2 C1 R2 Rev. 2.0 © 2012 Semtech Corporation SC4215J Pin Configuration Ordering Information Device Package SC4215JSETRT(1)(2) SOIC-8-EDP SC4215JEVB Evaluation Board Notes: (1) Available in tape and reel only. A reel contains 2,500 devices. (2) Available in lead-free package only. Device is WEEE and RoHS compliant and halogen free. Marking Information S C 4 2 1 5J SC4215J Absolute Maximum Ratings Recommended Operating Conditions VIN, EN, VO, FB to GND (V) . . . . . . . . . . . . . . . . . . -0.3 to +7.0 VIN (V). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4 < VIN < 6.0 Power Dissipation. . . . . . . . . . . . . . . . . . . . . . Internally Limited Junction Temperature Range (°C). . . . . . . . . . -40 < TJ < +125 ESD Protection Level (kV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Maximum Output Current (A). . . . . . . . . . . . . . . . . . . . . . . . . 2 (1) Thermal Information Thermal Resistance, Junction to Ambient(2) (°C/W) . . . . 36 Thermal Resistance, Junc to Case(2) (°C/W). . . . . . . . . . . . 5.5 Maximum Junction Temperature (°C). . . . . . . . . . . . . . +150 Storage Temperature Range (°C) . . . . . . . . . . . . -65 to +150 Peak IR Reflow Temperature (10s to 30s) (°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: (1) Tested according to JEDEC standard JESD22-A114-B. (2) 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. Electrical Characteristics Unless specified: VEN = VIN, VFB = VO, VIN = 1.40V to 6.0V, IO = 10µA to 2A, TJ = 25° C. Values in bold apply over the full operating temperature range. Parameter Symbol Conditions Max Units 6.0 V 3 mA 10 50 µA 90 400 VIN = 3.3V, IO = 0A IQ VIN = 6.0V, VEN =0V IO =1A Dropout Voltage(2)(3) Typ 1.4 VIN Operating Range (1) Quiescent Current Min VDO IO =1.5A IO = 2A Minimum Load Current(4) IO Current Limit ICL 1.4V ≤ VIN < 1.6V 200 1.6V ≤ VIN ≤ 6.0V 1.4V ≤ VIN < 1.6V 200 500 mV 300 1.6V ≤ VIN ≤ 6.0V 1.4V ≤ VIN < 1.6V 300 600 400 1.6V ≤ VIN ≤ 6.0V 2.1 3 10 µA 4.4 A SC4215J Electrical Characteristics (continued) Parameter Symbol Conditions Min Typ Max Units Feedback 0.495 Reference Voltage(2) VREF Line Regulation Load Regulation (5) Feedback Pin Current VIN = 3.3V, IO =10mA 0.505 0.500 0.490 0.510 0.485 0.515 V IO = 10mA 0.2 %/V IO = 10mA to 2A 0.3 % VFB = VREF 80 200 nA VEN = 0V, VIN =3.3V 1.5 10 µA EN Enable Pin Current Enable Pin Threshold IEN VIH VIL 1.6 VIN=3.3V V 0.4 Over Temperature Protection High Trip Level Hysteresis THI 160 O C THYST 10 O C Soft-Start Soft-Start Time (6) tSS 0.7 1 ms Notes: (1) Minimum VIN = VOUT + VDO or 1.4V, whichever is greater. (2) Low duty cycle pulse testing with Kelvin connections required. (3) VDO = VIN -VO when VO decreases by 1.5% of its nominal output voltage with VIN = VO +0.8V. (4) Required to maintain regulation. Voltage set resistors R1 and R2 are usually utilized to meet this requirement. (5) Where the power dissipation does not exceed the maximum rating of the package. Refer to Figure 1 on page 8. (6) Time taken for the output to rise from 0% to 95% of the programmed output voltage. SC4215J Typical Characteristics Dropout Voltage at VO = 1.5V 0 .4 0 .4 0.3 0.3 Dropout Voltage (V) Dropout Voltage (V) Dropout Voltage at VO = 3.3V 0.2 2 5 °C 1 2 5 °C 0.1 0.2 0.1 -4 0 °C -4 0 °C 0 .0 0 .0 0 .5 1.0 Load Current (A) 1.5 0 .0 2 .0 0 .0 3 .5 1200 3 .0 1000 2 .5 1 .0 Load Current (A) 1 .5 2 .0 800 Tss (us) ILIM (A) 0 .5 Startup Time vs Temperature Current Limit vs Temperature 2 .0 1 .5 600 400 1 .0 200 0 .5 0 0 .0 -5 0 0 50 100 -5 0 150 0 50 100 150 o o Temperature ( C) Temperature ( C) EN Threshold vs VIN Power-Supply Ripple Rejection vs Frequency VIN = 5.0V, VOUT = 3.3V 70 2 .0 Io= 2A 60 1 .6 50 -40 o C PSRR(dB) Enable On Threshold (V) 2 5 °C 1 2 5 °C 1 .2 0 .8 125 o C 25 o C 40 Io= 0.1A 30 20 0 .4 10 0 .0 1 .0 2 .0 3 .0 4 .0 Input Voltage VIN (V) 5 .0 6 .0 0 1 0 0 .0 E+0 1 .0 E+3 1 0 .0 E+3 1 0 0 .0 E+3 1 .0 E +6 1 0 .0 E+6 Frequency (Hz) SC4215J Pin Descriptions Pin # Pin Name 2 EN Enable input. Driving this pin high turns on the regulator. Driving this pin low shuts off the regulator. If not driven from a control circuit, tie this pin to the VIN pin. 3 VIN Input supply pin. A large bulk capacitance should be placed close to this pin to ensure that the input supply does not sag below the minimum VIN. Also a minimum of 4.7uF ceramic capacitor should be placed directly at this pin. 6 VO Regulator output pin. Refer to the Applications Information section for output capacitor selection. 7 FB Inverting input of the error amplifier. This pin is used to set the output voltage (See typical Application Circuits on page 1). 8 GND 1, 4, 5 NC THERMAL PAD Pin Function Ground pin. No connection. The exposed pad enhances thermal performance and is not electrically connected to GND inside the package. It is recommended to connect the exposed pad to the ground plane. Block Diagram SS SC4215J Applications Information Introduction The SC4215J 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 area. Additional features include an enable pin to allow for a very low power consumption in standby mode, and a fully adjustable output. device being some distance from any bulk capacitance on the rail. Additionally, the input droop due to load transients is reduced, improving load transient response. Additional capacitance may be added if required by the application. Output Capacitor By connecting the FB pin directly to the VO pin, the output voltage will be regulated to the 0.5V internal reference. A minimum bulk capacitance of 10µF/A (output load), along with a 0.1µF ceramic decoupling capacitor is recommended. For VO less than 0.6V, a minimum bulk capacitance of 40µF, along with a 0.1µF ceramic decoupling capacitor is recommended. 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 SC4215J is extremely tolerant of output capacitor ESR values and thus will also work comfortably with tantalum output capacitors. VO Setting with External Resistors Soft-Start The use of 1% resistors, and designing for a current flow ≥ 10µA is recommended to ensure a well regulated output (thus R2 ≤50kΩ). A suitable value for R2 can be chosen in the range of 1kΩ to 50kΩ. R1 can then be calculated from. The soft-start is achieved by using a voltage ramp as the voltage reference for the internal error amplifier during startup. This voltage ramp is created by an internal current source charging an internal soft-start capacitor. When the voltage ramp reaches 500mV, the voltage reference for the internal error amplifier switches to the fixed 500mV VREF. Thus, during soft-start, the output tracks the internal voltage ramp, which limits the input inrush current and provides a programmed soft-start profile for a wide range of applications. Noise Immunity In very electrically noisy environments, it is recommended that 0.1µF ceramic capacitors be placed from VIN to GND and VO to GND as close to the device pins as possible. VO Setting: VO=VREF 5 =5 ⋅ (92 − 95() ) 95() Enable Pulling this pin below 0.4V turns the regulator off, reducing the quiescent current to a fraction of its operating value. Driving this pin high enables the regulator. A pull up resistor up to 400kOhms should be connected from this pin to the VIN pin in applications where the Enable pin is not driven from a control circuit. Input Capacitor A large bulk capacitance ≥ 10µF/A (output load) should be placed close to the input supply pin of the SC4215J to ensure that VIN does not drop below the minimum VIN. Also a minimum of 4.7µF ceramic capacitor is recommended to be placed directly next to the VIN pin. This allows for the Over-Current and Thermal Shutdown The over-current protection and thermal shutdown functions protect the regulator against damage due to excessive power dissipation. The SC4215J is designed to current limit when the output current reashes 3A (typical). When the load exceeds 3A, the output voltage is reduced to maintain a constant current limit. The thermal shutdown function limits the junction temperature to a maximum of 160OC (typical). Thermal shutdown turns off the regulator as the junction temperature begins to exceed 160OC. When the junction temperature SC4215J Applications Information (Cont.) drops below 150OC (typical), the regulator is turned on again. Thermal Considerations The power dissipation in the SC4215J is given by the following equation: PD ≈ IO(VIN - VO) The allowable power dissipation will be dependant upon the thermal impedance achieved in the application. The derating curve below is valid for the thermal impedance specified in the Thermal Information section on page 3. Figure 1. Power Derating Curve SC4215J Outline Drawing — SOIC-8-EDP-2 SC4215J Land Pattern — SOIC-8-EDP-2 10 SC4215J © Semtech 2012 All rights reserved. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. No liability will be accepted by the publisher for any consequence of its use. Publication thereof does not convey nor imply any license under patent or other industrial or intellectual property rights. Semtech assumes no responsibility or liability whatsoever for any failure or unexpected operation resulting from misuse, neglect improper installation, repair or improper handling or unusual physical or electrical stress including, but not limited to, exposure to parameters beyond the specified maximum ratings or operation outside the specified range. SEMTECH PRODUCTS ARE NOT DESIGNED, INTENDED, AUTHORIZED OR WARRANTED TO BE SUITABLE FOR USE IN LIFESUPPORT APPLICATIONS, DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF SEMTECH PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE UNDERTAKEN SOLELY AT THE CUSTOMER’S OWN RISK. Should a customer purchase or use Semtech products for any such unauthorized application, the customer shall indemnify and hold Semtech and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs damages and attorney fees which could arise. Notice: All referenced brands, product names, service names and trademarks are the property of their respective owners. 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