LT433NCRPA ADJUSTABLE PRECISION SHUNT REGULATION. General Description. Features. Applications. Block Diagram & Symbol 2017/06/16

Transcription

1 General Description The LT433NCRPA is a low voltage three terminal adjustable shunt regulator with a guaranteed thermal stability over applicable temperature ranges. The output voltage can be set to any value between 1.24V (VREF) to 28V with two external resistors (see application circuit). The high precise Reference voltage tolerance is available in ±1.%. This device has a typical output impedance of.2ω. Active output circuitry provides a very sharp turn on characteristic, making this device excel lent replacement for Zener diodes in many applications. The LT433NCRPA is characterized for operation from -4 C to 125 C. The LT433NCRPA is available in a low profile SOT23-3L package. Features Precision reference voltage : LT433NCRPA : 1.24V±1.% Adjustable output voltage is VREF to 28V Sink current capability is 15mA Low dynamic output impedance is.2ω (typ.) Minimum Cathode current for regulation is.2ma (typ.) Plastic material has UL flammability classification 94V- Applications Switching Mode Power Supply Voltage Reference Application Block Diagram & Symbol Please be aware that an Important Notice concerning availability, disclaimers, and use in critical applications of LSC products is at the end of this document. 1 of 12

2 Ordering Information LT 433 X X X X X Packing Lead Pin-out Package Reference Voltage Reference Voltage Tolerance Package Type Pin-out Version Lead Packing N : ±1.% C : SOT23-3L R 1. REF P : RoHS & Halogen Free A : Tape & Reel (SOT23-3L) 2. CATHODE (ref. IEC ) 3. ANODE Product Number Output Voltage Tolerance Package Lead Packing LT433NCRPA 1. % SOT23-3L RoHS & Halogen Free Taping & Reel 2 of 12

3 Pin Assignment SOT23-3L (Top View) 2 LT433NCRPA 1. R 2. C 3. A 3 1 Pin Descriptions Pin Name Pin Description R A C Ref Anode Cathode 3 of 12

4 Absolute Maximum Ratings (at T A =25 C) Note : Operate over the Absolute Maximum Ratings may cause permanent damage to the device. Exposure to such conditions for extended time may still affect the reliability of the device. Characteristics Symbol Rating Unit Cathode Voltage V KA 3 V Continuous Cathode Current I KA 15 ma Reference Input Current I REF 1 ma Junction Temperature T J 15 C Storage Temperature T STG -4~15 C Thermal Resistance (Junction to Case) SOT23-3L θjc 11 C/W Thermal Resistance (Junction to Ambient) SOT23-3L θja 35 C/W Power dissipation SOT23-3L P D 285 mw Moisture Sensitivity MSL Please refer the MSL label on the IC package bag/carton for detail Note1 : Ratings apply to ambient temperature at 25 C Recommended Operating Conditions Characteristics Symbol Min Max Unit Cathode Voltage V KA V REF 28 V Cathode Current I KA.3 1 ma Operating Temperature (Operating free-air temperature) T A C 4 of 12

5 Electrical Characteristics (TA=25 C, unless otherwise specified) Characteristics Symbol Conditions Min Typ Max Unit Reference Voltage V REF V KA = V REF, I KA = 1mA (Fig.1) 1. % V Deviation of Reference Input Voltage over full temperature Range ( *Note 2) V REF(DEV) V KA = V REF, I KA = 1mA, T A = -2~85 C (Fig.1) V KA = V REF, I KA = 1mA, T A = -4~125 C (Fig.1) mv Reference Input Current I REF R1 = 1KΩ,R2 =, I KA= 1mA (Fig.2) ua Deviation of Reference Input Current over Temperature ( *Note 2) I REF(DEV) R1 = 1KΩ,R2 =, I KA = 1mA T A = -4~125 C(Fig.2) ua Ratio of the Change in Reference Voltage to the Change in Cathode Voltage V REF/ V KA I KA = 1mA (Fig.2) V KA = 2V ~V REF mv/v Minimum Cathode Current for Regulation I KA(min) V KA = V REF (Fig.1).15.3 ma Off-state Cathode Current I KA(OFF) V KA = 2V, V REF = V (Fig.3).1 1 ua Dynamic Output Impedance Z KA V KA = V REF Frequency 1KHz (Fig.1).5 1 Ω Note 2 : Thes speicifications are guaranteed by designed and are not tested when in mass-production. 5 of 12

6 Application Circuit Fig1: V KA =V REF Fig2: V KA >V REF Fig3: Off state current 6 of 12

7 Typical Characteristics REFERENCE VOLTAGE VS. FREE-AIR TEMPERTURE V ref - Reference Voltage (V) T A - Free-Air Temperature( C) V KA =V ref I KA =1mA REFERENCE CURRENT VS. FREE-AIR TEMPERATURE I ref - Reference Current(uA) R1=1KΩ R2= I KA =1mA T A - Free-Air Temperature( C) CATHODE CURRENT VS. CATHODE VOLTAGE CATHODE CURRENT VS. CATHODE VOLTAGE 1 I KA - Cathode Current (ma) V KA =V ref T A =25 C V KA - Cathode Voltage(V) I KA - Cathode Current (ua) V KA =V ref T A =25 C V KA - Cathode Voltage(V) OFF-STATE CATHODE CURRENT VS. FREE-AIR TRMPERATURE RATIO OF DELTA REFERENCE VOLTAGE TO DELTA CATHODE VOLTAGE VS. FREE-AIR TEMPERATURE I KOFF Off-state cathode current (ua) V KA =5V V REF = V ref / V KA (mv/v) V KA =V REF to 2V T A - Free-Air Temperature( C) T A - Free-Air Temperature( C) 7 of 12

8 Typical Characteristics (Continued) (1) Small Signal Voltage Amplification Vs Frequency A v -Small Signal Voltage Amplification (db) f-frequency(khz) I KA =1mA T A =25 C Test Circuit for Voltage Amplification (2) Reference Impedance VS Frequency 1 ZKA Reference Impedance (Ω) 1 1 I KA =1mA T A =25 C.1 1K 1K 1K f-frequency(hz) M 1M Test Circuit for Reference Impedance 8 of 12

9 Typical Characteristics (Continued) (3) Pulse Response 6 Input and and Output Voltage (V) Input Output T A =25 C t - Time (us) Test Circuit for Pulse Response (4) Stability boundary conditions 1 9 T A =25 C I KA - Cathode Current (ma) A V KA =VREF Stable A Unstable Stable A Test Circuit for V KA=V REF C L - Load Capacitance (uf) 1 Above curves represented the I KA and C L that caused 433 to oscillate when V KA=V REF. For V KA=5V/1V/15V, 433 was stable in all I KA and C L conditions. Test Circuit for V KA=5V/1V/15V * R2 and V I were adjusted to establish the initial V KA and I KA conditions with C L=. V BATT and C L were then adjusted to determine the ranges of stability. 9 of 12

10 Marking Information (1) SOT23-3L 1) SS = Internal control code 2) = Marking Number LT433NCRPA: NER 1 of 12

11 Mechanical Information (1) Package type: SOT23-3L Unit: mm Symbol Min Max A A1 -.1 A b.3.5 c.7.18 D E E e.95 REF e L.3.5 L1 Gauge Plane.55 REF.25 BSC θ 8 11 of 12

12 MSL (Moisture Sensitive Level) Information IPC/JEDEC J-STD-2D.1 Moisture Sensitivity Levels Table FLOOR LIFE LEVEL TIME CONDITION 1 Unlimited 3 C /85% 2 1 year 3 C /6% 2a 4 weeks 3 C /6% hours 3 C /6% 4 72 hours 3 C /6% 5 48 hours 3 C /6% a 24 hours 3 C /6% 6 Time on Label 3 C /6% (TOL) SOAK REQUIREMENTS Accelerated Equivalent 1 Standard ev ev CONDITION TIME TIME TIME CONDITION (hours) (hours) (hours) C /85% +5/- NA NA NA C /6% +5/- NA NA NA C /6% /- -1/+ -1/+ 6 C/ 6% C /6% /- -1/+ -1/+ 6 C/ 6% C /6% /- +.5/- +.5/- 6 C/ 6% C /6% /- +.5/- +.5/- 6 C/ 6% C /6% /- +.5/- +.5/- 6 C/ 6% TOL 3 C /6% NA NA NA Note 1: CAUTION - To use the accelerated equivalent soak conditions, correlation of damage response (including electrical, after soak and reflow), should be established with the standard soak conditions. Alternatively, if the known activation energy for moisture diffusion of the package materials is in the range of ev or ev, the accelerated equivalent may be used. Accelerated soak times may vary due to material properties (e.g.mold compound, encapsulant, etc.). JEDEC document JESD22-A12 provides a method for determining the diffusion coefficient. Note 2: The standard soak time includes a default value of 24 hours for semiconductor manufacturer s exposure time (MET) between bake and bag and includes the maximum time allowed out of the bag at the distributor s facility. If the actual MET is less than 24 hours the soak time may be reduced. For soak conditions of 3 C/6%, the soak time is reduced by 1 hour for each hour the MET is less than 24 hours. For soak conditions of 6 C/6%, the soak time is reduced by 1 hour for each 5 hours the MET is less than 24 hours. If the actual MET is greater than 24 hours the soak time must be increased. If soak conditions are 3 C/6%, the soak time is increased 1 hour for each hour that the actual MET exceeds 24 hours. If soak conditions are 6 C/6%, the soak time is increased 1 hour for each 5 hours that the actual MET exceeds 24 hours. Important Notice and Disclaimer LSC reserves the right to make changes to this document and its products and specifications at any time without notice. Customers should obtain and confirm the latest product information and specifications before final design, purchase or use. LSC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does LSC assume any liability for application assistance or customer product design. LSC does not warrant or accept any liability with products which are purchased or used for any unintended or unauthorized application. No license is granted by implication or otherwise under any intellectual property rights of LSC. LSC products are not authorized for use as critical components in life support devices or systems without express written approval of LSC. 12 of 12