SC431LCSK-1TR

Low Voltage Adjustable Shunt Regulator POWER MANAGEMENT Description The SC431L is a three terminal adjustable shunt regulator with thermal stability guaranteed over temperature. The output voltage can be adjusted to any value from 1.24V (V REF ) to 20V with two external resistors. The SC431L has a typical dynamic output impedance of 0.05Ω. Active output circuitry provides a very sharp turn on characteristic, making the SC431L an excellent replacement for zener diodes. The SC431L shunt regulator is available with four voltage tolerances (0.25%, 0.5%, 1.0% and 2.0%), two operating temperature ranges (commercial and industrial) and two package options (SOT-23-3 and SOT-235). This allows the designer the opportunity to select the optimum combination of cost and performance for their application. SC431L Features Low voltage operation (down to 1.24V) Wide operating current range 100µA to 100mA Low dynamic output impedance 0.05 Ω typ. Trimmed bandgap design ± 0.25% Upgrade for TLV431A SOT-23-3 and SOT-23-5 packages. Also available in Lead-free package, fully WEEE and RoHS compliant Applications Linear Regulators Adjustable Supplies Switching Power Supplies Battery Operated Computers Instrumentation Computer Disk Drives Typical Application Circuit(1)(2) Notes: 1) Set VOUT according to the following equation: R1   VOUT = VREF 1 +  + IREF R1 R2   2) Choose the value for R as follows: • The maximum limit for R should be such that the cathode current, I Z , is greater than the minimum operating current (100µA) at VIN(MIN). • The minimum limit for R should be such that IZ does not exceed 100mA under all load conditions, and the instantaneous turn-on value for I Z d oes not exceed 150mA. Both of the following conditions must be met: R min ≥ V IN (max) 150 mA (to limit instantaneous turn-on IZ) R min ≥ V IN (max) − V OUT I OUT (min) + 100 mA (to limit IZ under normal operating conditions) Revision: May 16, 2008 1 www.semtech.com SC431L POWER MANAGEMENT Absolute Maximum Ratings Parameter Cathode Voltage Continous Cathode Current Reference Input Current Power Dissipation at TA = 25°C SOT-23-3 SOT-23-5 Thermal Resistance SOT-23-3 SOT-23-5 Operating Ambient Temperature Range S C 431LC S C 431LI Operating Junction Temperature Range S C 431LC S C 431LI Storage Temperature Range Lead Temperature (Soldering) 10 seconds ESD Rating (Human Body Model) Symbol VZ IZ IREF PD Maximum 20 100 3 0.37 0.49 336 256 0 to +70 -40 to +85 0 to +150 -40 to +150 -65 to +150 300 2 Units V mA mA W θJ A °C/W TA °C TJ TSTG TLEAD V ESD °C °C °C kV Electrical Characteristics Unless specified:TA = 25°C. Values in bold apply over full operating ambient temperature range. SC431L 0.25% Parameter Reference Voltage Symbol VREF Condition VZ = VREF, IZ = 10mA(1) Min 1.237 1.224 VREF Temp Deviation Ratio of Change in VREF to Change in VZ Reference Input Current IREF Temperature Deviation Off-State Cathode Current V D EV VZ = VREF, IZ = 10mA(1) IZ = 10mA, ∆VZ = 16V to VREF 10 -1.0 Typ 1.240 Max 1.243 1.256 25 -2.7 SC431L 0.5% Min 1.234 1.222 10 -1.0 Typ 1.240 Max 1.246 1.258 25 -2.7 mV mV/V Units V ∆VREF ∆VZ IREF IREF(DEV) IZ (OFF) R1 = 10kΩ, R2 = ∞, IZ = 10mA(2) R1 = 10kΩ, R2 = ∞, IZ = 10mA(2) VREF = 0V, VZ = 6V(3) VREF = 0V, VZ = 16V(3) 0.15 0.1 0.125 0.135 0.5 0.4 0.150 0.150 0.15 0.1 0.125 0.135 0.5 0.4 0.150 0.150 µA µA µA  2008 Semtech Corp. 2 www.semtech.com SC431L POWER MANAGEMENT Electrical Characteristics (Cont.) Unless specified:TA = 25°C. Values in bold apply over full operating ambient temperature range. (Continued from page 2) Parameter Dynamic Output Impedance Minimum Operating Current Symbol rZ IZ (MIN) Condition f < 1kHz, VZ = VREF IZ = 100µA to 100mA(1) VZ = VREF(1) SC431L 0.25% Min Typ 0.05 20 Max 0.15 100 SC431L 0.5% Min Typ 0.05 20 Max 0.15 100 Units Ω µA S C 431L 1% Parameter Reference Voltage Symbol VREF Condition VZ = VREF, IZ = 10mA(1) Min 1.228 1.215 VREF Temp Deviation Ratio of Change in VREF to Change in VZ Reference Input Current IREF Temperature Deviation Off-State Cathode Current Dynamic Output Impedance Minimum Operating Current rZ IZ (MIN) V D EV VZ = VREF, IZ = 10mA(1) IZ = 10mA, ∆VZ = 16V to VREF 10 -1.0 Typ 1.240 Max 1.252 1.265 25 -2.7 S C 431L 2% Min 1.215 1.200 10 -1.0 Typ 1.240 Max 1.265 1.280 35 -2.7 mV mV/V Units V ∆VREF ∆VZ IREF IREF(DEV) IZ (OFF) R1 = 10kΩ, R2 = ∞, IZ = 10mA(2) R1 = 10kΩ, R2 = ∞, IZ = 10mA(2) VREF = 0V, VZ = 6V(3) VREF = 0V, VZ = 16V(3) f < 1kHz, VZ = VREF IZ = 100µA to 100mA(1) VZ = VREF(1) 0.15 0.1 0.125 0.135 0.05 20 0.5 0.4 0.150 0.150 0.15 100 0.15 0.1 0.125 0.135 0.05 20 0.5 0.4 0.150 0.150 0.15 100 µA µA µA Ω µA Notes: (1) See Test Circuit 1 on page 4. (2) See Test Circuit 2 on page 4. (3) See Test Circuit 3 on page 4. Recommended Operating Conditions Min Cathode Voltage, VZ Cathode Current, IZ VREF 100µA Max 16 100 Symbol V mA  2008 Semtech Corp. 3 www.semtech.com SC431L POWER MANAGEMENT Test Circuits Test Circuit 1 VZ = VREF Test Circuit 2 VZ > VREF Test Circuit 3 Off-State Pin Configurations SOT-23-3 (Top View) SOT-23-5 (Top View) Block Diagram Symbol  2008 Semtech Corp. 4 www.semtech.com SC431L POWER MANAGEMENT Ordering Information P ackag e TJ (°C) 0.25% SOT-23-3(1)(2) 0 to +150 SC431LCSK-.25TR SC431LCSK-25TRT -40 to +150 SC431LISK-.25TR SC431LISK-.25TRT SOT-23-5(1)(2) 0 to +150 SC431LC5SK.25TR SC431LC5SK25TRT -40 to +150 SC431LI5SK.25TR SC431LI5SK25TRT 0.5% SC431LCSK-.5TR SC431LCSK-.5TRT SC431LISK-.5TR SC431LISK-.5TRT SC431LC5SK-.5TR SC431LC5SK.5TRT SC431LI5SK-.5TR SC431LI5SK.5TRT Tolerance 1.0% SC431LCSK-1TR SC431LCSK-1TRT SC431LISK-1TR SC431LISK-1TRT SC431LC5SK-1TR SC431LC5SK-1TRT SC431LI5SK-1TR SC431LI5SK-1TRT 2.0% SC431LCSK-2TR SC431LCSK-2TRT SC431LISK-2TR SC431LISK-2TRT SC431LC5SK-2TR SC431LC5SK-2TRT SC431LI5SK-2TR SC431LI5SK-2TRT Notes: (1) Only available in tape and reel packaging. A reel contains 3000 devices. (2) “T” at end of part number indicates “lead free”. This product is fully WEEE and RoHS compliant. Marking Information SOT-23-3 (Top View only) (0 to +150°C) SOT-23-5 (Top View) (-40 to +150°C) SOT-23-5 (Top View) (0 to +150°C) 31L L5I 431L SOT-23-3 (Top View only) (-40 to +150°C) SOT-23-5 (Bottom View) SOT-23-5 (Bottom View) 3LI yyww yyww = Datecode, Example: (0115) yyww yyww = Datecode, Example: (0015)  2008 Semtech Corp. 5 www.semtech.com SC431L POWER MANAGEMENT Typical Characteristics Cathode Current vs. Cathode Voltage 300 200 100 0 -100 -200 -300 -1 -0.5 0 VZ (V) 0.5 1 1.5 IZ (mA) IZ (µA) VZ = VREF TA = 25 C o Cathode Current vs. Cathode Voltage 150 100 50 0 -50 -100 -150 -1.5 -1 -0.5 0 VZ (V) 0.5 1 1.5 VZ = VREF TA = 25 C o Reference Voltage vs. Junction Temperature 1.248 IZ = 10mA 1.246 1.244 VREF (V) 1.242 1.240 1.238 1.236 1.234 -50 -25 0 25 50 TJ (°C) 75 100 125 150 50 -50 IZ = 60µA 75 IREF (nA) 125 150 Reference Input Current vs. Junction Temperature IZ = 10mA R1 = 10kΩ R2 = ∞ 100 -25 0 25 50 TJ (°C) 75 100 125 150 Ratio of Delta Reference Voltage to Delta Cathode Voltage vs. Junction Temperature 1.2 1.1 1.0 VREF / VZ (-mV/V) 0.9 0.8 0.6 0.5 0.4 0.3 0.2 0.1 0.0 -50 -25 0 25 50 TJ (°C) 75 100 125 150 0 -50 -25 50 IZ(off) (nA) 0.7 150 IZ = 10mA ∆VZ = 16V to VREF 250 Off-State Cathode Current vs. Junction Temperature VREF = 0V VZ = 16V 200 100 VZ = 6 V 0 25 50 TJ (°C) 75 100 125 150  2008 Semtech Corp. 6 www.semtech.com SC431L POWER MANAGEMENT Typical Characteristics (Cont.) Reference Impedance vs. Junction Temperature 0.50 0.45 0.40 0.35 0.30 rZ ( ) 0.25 0.20 0.15 0.10 0.05 0.00 -50 -25 0 25 50 TJ (°C) 75 100 125 150 0.01 1.E+03 0.1 rZ (Ω) 1 100 IZ = 0.1 to 100 mA VZ = VREF f < 1 kHz TA = 25°C Reference Impedance vs. Frequency 10 1.E+04 1.E+05 f (Hz) 1.E+06 1.E+07 Small-Signal Gain and Phase Shift vs. Frequency 80 70 60 50 AV (dB) 40 30 20 10 0 -10 -20 1.0E+02 1.0E+03 1.0E+04 f (Hz) 1.0E+05 -180 -225 -270 Phase Shift (deg) -315 -360 -405 -450 -495 -540 -585 -630 1.0E+06 Test Circuit - Small-Signal Gain and Phase Stability Boundary Condition For Shunt Regulation vs. Cathode Current and Load Capacitance 3.5 TA = 25°C 3.0 Stable 2.5 IZ (mA) 2.0 1.5 VZ = VREF 1.0 0.5 0.0 0.001 Stable Test Circuit - Stability VZ = 2 V 0.01 0.1 CL (µF) 1 10  2008 Semtech Corp. 7 www.semtech.com SC431L POWER MANAGEMENT Applications Information - Stability Selection of load capacitance when using SC431L as a shunt regulator When the SC431L is used as a shunt regulator, two options for selection of CL (see diagram on page 7) are recommended for optimal stability: 1) No load capacitance across the device, decouple at the load. 2) Large capacitance across the device, optional decoupling at the load. The reason for this is that SC431L exhibits instability with capacitances in the range of 10nF to 1µF (approx.) at light cathode currents (up to 3mA typical). The device is less stable the lower the cathode voltage has been set for. Therefore while the device will be perfectly stable operating at a cathode current of (say) 10mA with a 0.1µF capacitor across it, it will oscillate transiently during startup as the cathode current passes through the instability region. Selecting a very low (or preferably, no) capacitance, or alternatively a high capacitance (such as 10µF) will avoid this issue altogether. Since the user will probably wish to have local decoupling at the load anyway, the most cost effective method is to use no capacitance at all directly across the device. PCB trace/ via resistance and inductance prevent the local load decoupling from causing the oscillation during the transient start-up phase. Note: if the SC431L is located right at the load, so the load decoupling capacitor is directly across it, then this capacitor will have to be ≤ 1nF or ≥ 10µF.  2008 Semtech Corp. 8 www.semtech.com SC431L POWER MANAGEMENT Outline Drawing - SOT-23-3 D e1 3 B A DIM A A1 A2 b c D E E1 e e1 L L1 N 0 aaa bbb DIMENSIONS INCHES MILLIMETERS MIN NOM MAX MIN NOM MAX .035 .000 .035 .012 .003 .110 .082 .047 .015 0° .037 .114 .093 .051 .075 .037 .020 .022 3 .004 .008 .044 .004 .040 .020 .007 .120 .104 .055 .024 8° 0.89 1.12 0.01 0.10 0.88 0.95 1.02 0.51 0.30 0.18 0.08 2.80 2.90 3.04 2.10 2.37 2.64 1.20 1.30 1.40 1.90 BSC 0.95 BSC 0.40 0.50 0.60 (0.55) 3 0° 8° 0.10 0.20 E1 E 1 2 bxN e bbb CAB A A2 3X aaa C SEATING PLANE A1 C H SEATING PLANE C GAUGE PLANE 0.25 L L1 DETAIL A 0 c SIDE VIEW NOTES: SEE DETAIL A 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. DATUMS -A- AND -BTO BE DETERMINED AT DATUM PLANE -H3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. Land Pattern - SOT-23-3 X Y DIM Z G C C E E1 G X Y Z DIMENSIONS INCHES MILLIMETERS (.087) .037 .075 .031 .039 .055 .141 (2.20) 0.95 1.90 0.80 1.00 1.40 3.60 Y E 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. E1 Note: (1) Grid placement courtyard is 8 x 8 elements (4mm x 4mm) in accordance with the international grid detailed in IEC Publication 97.  2008 Semtech Corp. 9 www.semtech.com SC431L POWER MANAGEMENT Outline Drawing - SOT-23-5 A e1 N EI DIM D A A1 A2 b c D E1 E e e1 L L1 N 01 aaa bbb ccc A DIMENSIONS INCHES MILLIMETERS MIN NOM MAX MIN NOM MAX .035 .000 .035 .010 .003 .110 .060 .045 .057 .006 .051 .020 .009 .118 .069 0.90 0.00 .90 0.25 0.08 2.80 1.50 1.15 1.45 0.15 1.30 0.50 0.22 3.00 1.75 2X E/2 E 1 ccc C 2X N/2 TIPS 2 e B D aaa C A2 SEATING PLANE .114 .063 .110 BSC .037 BSC .075 BSC .012 .018 .024 (.024) 5 0° 10° .004 .008 .008 2.90 1.60 2.80 BSC 0.95 BSC 1.90 BSC 0.30 0.45 0.60 (0.60) 5 0° 10° 0.10 0.20 0.20 C A1 bxN H bbb C A-B D GAGE PLANE 0.25 L (L1) c 01 SEE DETAIL SIDE VIEW A DETAIL A 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. Land Pattern - SOT-23-5 X DIM (C) G Y P Z C G P X Y Z DIMENSIONS MILLIMETERS INCHES (.098) .055 .037 .024 .043 .141 (2.50) 1.40 0.95 0.60 1.10 3.60 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  2008 Semtech Corp. 10 www.semtech.com