SC4211 Very Low Input /Very Low Dropout 1 Amp Regulator With Enable POWER MANAGEMENT Description Features The SC4211 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 1 amperes. It operates with a Vin as low as 1.4V, with output voltage programmable as low as 0.5V. The SC4211 features ultra low dropout, ideal for applications where Vout is very close to Vin. Additionally, the SC4211 has an enable pin to further reduce power dissipation while shutdown. The SC4211 provides excellent regulation over variations in line, load and temperature. Applications The SC4211 is available in the SOIC-8-EDP (Exposed Die Pad) package. Depending on how the FB pin is configured, the output voltage can be either externally adjusted or fixed to either 0.5V or 1V. Typical Application Circuits SC4211 4 3 VIN 2 1 Telecom/Networking cards Motherboards/Peripheral cards Industrial Applications Wireless infrastructure Set top boxes Medical equipment Notebook computers Battery powered systems 5 NC NC ENABLE Input Voltage as low as 1.4V 400mV dropout @ 1A Adjustable output from 0.5V Over current and over temperature protection Enable pin 10µA quiescent current in shutdown Full industrial temperature range Available in SOIC-8-EDP Lead-free package, fully WEEE and RoHS compliant VO VIN EN FB NC GND 6 VO 7 VO 0.5 (R1 + R2) R2 R1 8 U1 C1 = Volts C2 R2 SC4211 4 3 VIN 2 ENABLE 1 VO VIN EN FB NC GND C1 Revision: November 06, 2008 SC4211 5 4 NC NC U1 6 3 VIN VO = 0.5V 7 2 ENABLE 1 8 C1 C2 1 5 NC NC VIN VO EN FB NC GND U1 6 VO = 1V 7 8 C2 www.semtech.com SC4211 POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. Parameter Symbol Max Units 7 V PD Internally Limited W θJA 36 °C/W θJC 5.5 °C/W Operating Ambient Temperature Range TA -40 to +85 °C Operating Junction Temperature Range TJ -40 to +125 °C TSTG -65 to +150 °C TP 260 °C V ESD 2 kV Vin, EN, Vo, FB to GND Power Dissipation Thermal Resistance Junction to Ambient Thermal Resistance Junction to Case (1) (1) Storage Temperature Range Peak IR Reflow Temperature (10s to 30s) ESD Rating (Human Body Model) (2) Notes: (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, (2) Tested according to JEDEC standard JESD22-A114-B. Electrical Characteristics Unless specified: VEN = VIN, VFB = VO, VIN = 1.40V to 6.0V, IO = 10µA to 1A. Values in bold apply over the full operating temperature range. Parameter Symbol Test Conditions Min Typ Max Units 6.0 V 3 mA 10 50 µA VO +2% V VIN Supply Voltage Range VIN Quiescent Current IQ 1.40 VIN = 3.3V, IO = 0A VIN = 6.0V, VEN = 0V VO Output Voltage(1) VO (Fixed Voltage, VFB = 0) VIN = VO + 0.5V, IO = 10mA -2% 1.40V ≤ VIN ≤ 6.0V, IO = 10mA -3% +3% Line Regulation(1) REG(LINE) IO = 10mA 0.2 0.4 %/V Load Regulation(1) REG(LOAD) IO = 10mA to 1A 0.5 1.5 %/V V DO IO = 500mA 100 250 mV Dropout Voltage(1)(2) 300 2007 Semtech Corp. 2 www.semtech.com SC4211 POWER MANAGEMENT Electrical Characteristics (Cont.) Unless specified: VEN = VIN, VFB = VO, VIN = 1.40V to 6.0V, IO = 10µA to 1A. Values in bold apply over the full operating temperature range. Parameter Symbol Test Conditions VDO IO = 1A Minimum Load Current(3) IO VIN = VO + 0.5V Current Limit(4) ICL Min Typ Max 200 400 Units VO (Cont.) Dropout Voltage(1)(2) 500 mV 10 µA 1.1 1.5 2.0 A VIN = 3.3V, VFB = VOUT, IO = 10mA 0.495 0.5 0.505 V Full IOUT , and VIN Range 0.490 F eed b ack Reference Voltage(1) Feedback Pin Current(4) Feedback Pin Threshold (5) VREF IADJ VFB = VREF VTH(FB) 0.05 0.510 80 200 nA 0.16 0.40 V 1.5 10 µA EN Enable Pin Current IEN VEN = 0V, VIN = 3.3V Enable Pin Threshold VIH VIN = 3.3V VIL VIN = 3.3V 1.6 V 0.4 Over Temperature Protection High Trip level Hysteresis Notes: (1) (2) (3) (4) (5) THI 160 °C THYST 10 °C Low duty cycle pulse testing with Kelvin connections required. VDO = VIN -VO when VO decreases by 1.5% of its nominal output voltage with VIN = VO +0.8V. Required to maintain regulation. Voltage set resistors R1 and R2 are usually utilized to meet this requirement. Guaranteed by design. When VFB exceeds this threshold, the “Sense Select” switch disconnects the internal feedback chain from the error amplifier and connects VFB instead. 2007 Semtech Corp. 3 www.semtech.com SC4211 POWER MANAGEMENT Ordering Information Part Number P ackag e Temp. Range (TJ) SC4211STRT(1)(2) SOIC-8-EDP -40 to +125 OC SC4211EVB Evaluation Board Notes: (1) Only available in tape and reel packaging. A reel contains 2500 devices. (2) Lead-free product. This product is fully WEEE and RoHS compliant. Pin Configuration Top View Bottom View GND NC GND GND 8 EN FB FB 7 VIN VO VO 6 NC NC NC 5 SOIC-8-EDP-2 Exposed Die Pad 1 NC 2 EN 3 VIN 4 NC SOIC-8-EDP-2 Pin Descriptions Pin # Pin Name Pin Desciption 2 EN Enable Input. Pulling this pin below 0.4V turns the regulator off, reducing the quiescent current to a fraction of its operating value. The device will be enabled if this pin is left open. Connect to VIN if not being used. 3 VIN Input voltage. For regulation at full load, the input to this pin must be between (VO+ 0.5V) and 5.5V. Minimum VIN = 1.4V. A large bulk capacitance should be placed closely to this pin to ensure that the input supply does not sag below 1.4V. Also a minimum of 4.7uF ceramic capacitor should be placed directly at this pin. 6 VO The pin is the power output of the device. A minimum of 10uF capacitor should be placed directly at this pin. 7 FB When this pin is grounded, an internal resistor divider sets the output voltage to 1.0V. If connected to the Vo pin, the output voltage will be set at 0.5V. If external feedback resistors are used, the output voltage will be (See Application Circuits on page 1): 0.5 (R1 + R2) VO = Volts R2 8 GND Reference ground. The GND pin and the exposed die pad must be connected together at the IC pin. 1,4,5 NC No Connection. THERMAL Pad for heatsinking purposes. Connect to ground plane using multiple vias. Not electrically connected PAD internally. 2007 Semtech Corp. 4 www.semtech.com SC4211 POWER MANAGEMENT Block Diagram FB 1.5uA 0.5 V 8V REF Marking Information Top View SC4211 yyww xxxxx yyww = Datecode (Example: 0015) xxxxx = Semtech Lot No. (Example: 00101) 2007 Semtech Corp. 5 www.semtech.com SC4211 POWER MANAGEMENT Typical Characteristics Region of Instability Stable Region Region of Instability Region of Instability Stable Region Region of Instability 2007 Semtech Corp. 6 www.semtech.com SC4211 POWER MANAGEMENT Applications Information Introduction Enable: Pulling this pin below 0.4V turns the regulator off, reducing the quiescent current to a fraction of its operating value. A pull up resistor up to 400kOhms should be connected from this pin to the VIN pin in application where supply voltages of Vin < 1.9V is required. For applications with higher voltages than 1.9V, EN pin could be left open or connected to VIN. The SC4211 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. Thermal Considerations Component Selection The power dissipation in the SC4211 is approximately equal to the product of the output current and the input to output voltage differential: Input capacitor: A large bulk capacitance of about ≥ 10uF/A (output load) should be closely placed to the input supply pin of the SC4211 to ensure that Vin does not sag below 1.4V. Also a minimum of 4.7µF ceramic 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, input droop due to load transients is reduced, improving load transient response. Additional capacitance may be added if required by the application. PD ≈ (VIN − VOUT )• I O The absolute worst-case dissipation is given by: PD(MAX) = (VIN (MAX) − VOUT (MIN) )• I O(MAX) + VIN (MAX) • I Q(MAX) For a typical scenario, VIN = 3.3V ± 5%, VOUT = 2.8V and IO = 1A, therefore: Output capacitor: A minimum bulk capacitance of ≥ 10µF/A (output load), 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 SC4211 is extremely tolerant of output capacitor ESR values and thus will also work comfortably with tantalum output capacitors. VIN(MAX) = 3.465V, VOUT(MIN) = 2.744V and IQ(MAX) = 1.75mA, Thus PD(MAX) = .722W. Using this figure, and assuming TA(MAX) = 70°C, we can calculate the maximum thermal impedance allowable to maintain TJ ≤ 150°C: R TH(J−A)(MAX) = 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. (T J(MAX) − TA(MAX) ) PD(MAX) = (150 − 70) = 110°C/W .722 This should be achievable for the SOIC-8-EDP package using PCB copper area to aid in conducting the heat away, such as one square inch of copper connected to the ground pins 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. Internal voltage selection: By connecting the FB pin to GND, an internal resistor divider will regulate the output voltage to 1.0V. If the FB pin is connected directly to the VO pin, the output voltage will be regulated to the 0.5V internal reference. 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). 2007 Semtech Corp. 7 www.semtech.com SC4211 POWER MANAGEMENT Outline Drawing - SOIC-8-EDP A D e N DIM 2X E/2 E1 E 1 2 ccc C 2X N/2 TIPS e/2 B D aaa C SEATING PLANE A2 A C A1 bxN bbb DIMENSIONS INCHES MILLIMETERS MIN NOM MAX MIN NOM MAX A A1 A2 b c D E1 E e F H h L L1 N 01 aaa bbb ccc .069 .053 .005 .000 .065 .049 .020 .012 .010 .007 .189 .193 .197 .150 .154 .157 .236 BSC .050 BSC .116 .120 .130 .085 .095 .099 .010 .020 .016 .028 .041 (.041) 8 8° 0° .004 .010 .008 C A-B D 1.75 1.35 0.13 0.00 1.65 1.25 0.51 0.31 0.25 0.17 4.80 4.90 5.00 3.80 3.90 4.00 6.00 BSC 1.27 BSC 2.95 3.05 3.30 2.15 2.41 2.51 0.25 0.50 0.40 0.72 1.04 (1.05) 8 0° 8° 0.10 0.25 0.20 h F EXPOSED PAD h H H c GAGE PLANE 0.25 SEE DETAIL L (L1) A DETAIL 01 A SIDE VIEW NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. DATUMS -A- AND -B- TO BE DETERMINED AT DATUM PLANE -H3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. 4. REFERENCE JEDEC STD MS-012, VARIATION BA. 2007 Semtech Corp. 8 www.semtech.com SC4211 POWER MANAGEMENT Land Pattern - SOIC-8-EDP E SOLDER MASK D DIM (C) F G C D E F G P X Y Z Z Y THERMAL VIA Ø 0.36mm P X DIMENSIONS INCHES MILLIMETERS (.205) .134 .201 .101 .118 .050 .024 .087 .291 (5.20) 3.40 5.10 2.56 3.00 1.27 0.60 2.20 7.40 NOTES: 1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. 2. REFERENCE IPC-SM-782A, RLP NO. 300A. 3. THERMAL VIAS IN THE LAND PATTERN OF THE EXPOSED PAD SHALL BE CONNECTED TO A SYSTEM GROUND PLANE. FAILURE TO DO SO MAY COMPROMISE THE THERMAL AND/OR FUNCTIONAL PERFORMANCE OF THE DEVICE. Contact Information Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804 2007 Semtech Corp. 9 www.semtech.com