LM4121AIM5-ADJ

LM4121 Precision Micropower Low Dropout Voltage Reference April 2000 LM4121 Precision Micropower Low Dropout Voltage Reference General Description The LM4121 is a precision bandgap voltage reference available in a fixed 1.25V and adjustable version with up to 5 mA current source and sink capability. This series reference operates with input voltages as low as 1.8V and up to 12V consuming 160 µA (Typ.) supply current. In power down mode, device current drops to less than 2 µA. The LM4121 comes in two grades A and Standard. The best grade devices (A) have an initial accuracy of 0.2%, while the standard have an initial accuracy of 0.5%, both with a tempco of 50ppm/˚C guaranteed from −40˚C to +125˚C. The very low operating voltage, low supply current and power-down capability of the LM4121 makes this product an ideal choice for battery powered and portable applications. The device performance is guaranteed over the industrial temperature range (−40˚C to +85˚C), while certain specs are guaranteed over the extended temperature range (−40˚C to +125˚C). Please contact National for full specifications over the extended temperature range. The LM4121 is available in a standard 5-pin SOT-23 package. Features (LM4121-1.2) n n n n n n n n n n Small SOT23-5 package Low voltage operation High output voltage accuracy: 0.2% ± 5 mA Source and Sink current output: Supply current: 160 µA Typ. Low Temperature Coefficient: 50 ppm/˚C Enable pin Output voltages: 1.25V and Adjustable Industrial temperature Range: −40˚C to +85˚C (For extended temperature range, −40˚C to 125˚C, contact National Semiconductor) Applications n n n n n n n n n n Portable, battery powered equipment Instrumentation and process control Automotive & Industrial Test equipment Data acquisition systems Precision regulators Battery chargers Base stations Communications Medical equipment LM4121-1.2 Block Diagram Connection Diagram DS101291-2 Refer to the Ordering Information Table in this Data Sheet for Specific Part Number SOT23-5 Surface Mount Package DS101291-1 * Resistors are removed on the LM4121-ADJ †LM4121-ADJ only DS101291-35 © 2000 National Semiconductor Corporation DS101291 www.national.com LM4121 Ordering Information Industrial Temperature Range (−40˚C to + 85˚C) Initial Output Voltage Accuracy at 25˚C And Temperature Coefficient 0.2%, 50 ppm/˚C max (A grade) 0.5%, 50 ppm/˚C max LM4121 Supplied as 1000 Units, Tape and Reel LM4121AIM5-1.2 LM4121AIM5-ADJ LM4121IM5-1.2 LM4121IM5-ADJ LM4121 Supplied as 3000 Units, Tape and Reel LM4121AIM5X-1.2 LM4121AIM5X-ADJ LM4121IM5X-1.2 LM4121IM5X-ADJ Top Marking R19A R20A R19B R20B SOT-23 Package Marking Information Only four fields of marking are possible on the SOT-23’s small surface. This table gives the meaning of the four fields. Field Information First Field: R = Reference Second and third Field: 19 = 1.250V Voltage Option 20 = Adjustable Fourth Field: A-B = Initial Reference Voltage Tolerance A = ± 0.2% B = ± 0.5% www.national.com 2 LM4121 Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Maximum Voltage on input or enable pins Output Short-Circuit Duration Power Dissipation (TA = 25˚C) (Note 2): MA05B package − θJA Power Dissipation ESD Susceptibility (Note 3) Human Body Model Machine Model 280˚C/W 350 mW 2 kV 200V −0.3V to 14V Indefinite Lead Temperature: Soldering, (10 sec.) Vapor Phase (60 sec.) Infrared (15 sec.) +260˚C +215˚C +220˚C Operating Range (Note 1) Storage Temperature Range Ambient Temperature Range Junction Temperature Range −65˚C to +150˚C −40˚C to +85˚C −40˚C to +125˚C Electrical Characteristics LM4121-1.250V Unless otherwise specified VIN = 3.3V, ILOAD = 0, COUT = 0.01µF, TA = Tj = 25˚C. Limits with standard typeface are for Tj = 25˚C, and limits in boldface type apply over the −40˚C ≤ TA ≤ +85˚C temperature range. Symbol VOUT Parameter Output Voltage Initial Accuracy LM4121A-1.250 LM4121-1.250 TCVOUT/˚C ∆VOUT/∆VIN Temperature Coefficient Line Regulation −40˚C ≤ TA ≤ +125˚C 1.8V ≤ VIN ≤ 12V 0 mA ≤ ILOAD ≤ 1 mA ∆VOUT/∆ILOAD 1 mA ≤ ILOAD ≤ 5 mA −1 mA ≤ ILOAD ≤ 0 mA −5 mA ≤ ILOAD ≤ −1 mA Min-VIN VN IS ISS Minimum Operating Voltage Output Noise Voltage Supply Current Power-down Supply Current VIN = 12V Enable = 0.4V Enable = 0.2V 1.6 1.5 0.4 0.2 IH IL Logic High Input Current Logic Low Input Current VIN = 3.3V, VOUT = 0 ISC Short Circuit Current 6 VIN = 12V, VOUT = 0 6 Hyst ∆VOUT Thermal Hysteresis (Note 8) Long Term Stability (Note 9) −40˚C ≤ TA ≤ 125˚C 1000 hrs. @ 25˚C 0.5 100 17 30 mV/V ppm 7 0.1 15 30 mA 15 µA µA ILOAD = 5mA 0.1 Hz to 10 Hz 10 Hz to 10 kHz 14 0.0007 0.03 0.01 0.04 0.01 1.5 20 30 160 250 275 1 2 1.8 V µVPP µVRMS µA Conditions Min (Note 5) Typ (Note 4) 1.250 Max (Note 5) Units ± 0.2 ± 0.5 50 0.009 0.012 0.08 0.17 0.04 0.1 0.12 % ppm/˚c %/V Load Regulation %/mA µA V V VH VL Logic High Input Voltage Logic Low Input Voltage 3 www.national.com LM4121 Electrical Characteristics LM4121-ADJ Unless otherwise specified VIN = 3.3V, VOUT = VREF, ILOAD = 0, COUT = 0.01µF, TA = Tj = 25˚C. Limits with standard typeface are for Tj = 25˚C, and limits in boldface type apply over the −40˚C ≤ TA ≤ +85˚C temperature range. Symbol VOUT = VREF Parameter Output Voltage Initial Accuracy LM4121A-ADJ LM4121-ADJ TCVREF/˚C ∆VREF/∆VIN Temperature Coefficient Line Regulation −40˚C ≤ TA ≤ +125˚C 1.8V ≤ VIN ≤ 12V 0 mA ≤ ILOAD ≤ 1 mA ∆VOUT/∆ILOAD 1 mA ≤ ILOAD ≤ 5 mA −1 mA ≤ ILOAD ≤ 0 mA −5 mA ≤ ILOAD ≤ −1 mA Min-VIN VN IS ISS Minimum Operating Voltage Output Noise Voltage (Note 6) Supply Current Power-down Supply Current VIN = 12V Enable = 0.4V Enable = 0.2V (Note 7) 15 1.6 40 1.5 0.4 0.2 IH IL Logic High Input Current Logic Low Input Current VOUT = 0 ISC Short Circuit Current 6 VIN = 12V, VOUT = 0 6 Hyst ∆VOUT Thermal Hysteresis (Note 8) Long Term Stability (Note 9) −40˚C ≤ TA ≤ 125˚C 1000 hrs. @ 25˚C 0.5 100 17 30 mV/V ppm 7 0.1 15 30 mA 15 µA µA ILOAD = 5 mA 0.1 Hz to 10 Hz 10 Hz to 10 kHz 14 0.0007 0.03 0.01 0.04 0.01 1.5 20 30 160 250 275 1 2 1.8 V µVPP µVRMS µA Conditions Min (Note 5) Typ (Note 4) 1.216 Max (Note 5) Units ± 0.2 ± 0.5 50 0.009 0.012 0.08 0.17 0.04 0.1 0.12 % ppm/˚c %/V Load Regulation %/mA µA nA V V IBIAS VH VL Reference Pin Bias Current Logic High Input Voltage Logic Low Input Voltage Note 1: “Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under the listed test conditions. Note 2: Without PCB copper enhancements. The maximum power dissipation must be de-rated at elevated temperatures and is limited by TJMAX (maximum junction temperature), θJ-A (junction to ambient thermal resistance) and TA (ambient temperature). The maximum power dissipation at any temperature is: PDissMAX = (TJMAX − TA)/θJ-A up to the value listed in the Absolute Maximum Ratings. Note 3: The human body model is a 100 pF capacitor discharged through a 1.5 kΩ resistor into each pin. The machine model is a 200 pF capacitor discharged directly into each pin. Note 4: Typical numbers are at 25˚C and represent the most likely parametric norm. Note 5: Limits are 100% production tested at 25˚C. Limits over the operating temperature range are guaranteed through correlation using Statistical Quality Control (SQC) methods. The limits are used to calculate National’s Averaging Outgoing Quality Level (AOQL). Note 6: Output noise for 1.25V option. Noise is proportional to VOUT. Note 7: Bias Current flows out of the Adjust pin. Note 8: Thermal hysteresis is defined as the change in +25˚C output voltage before and after exposing the device to temperature extremes. Note 9: Long term stability is change in VREF at 25˚C measured continuously during 1000 hrs. www.national.com 4 LM4121 LM4121- (All Options) Typical Operating Characteristics = 3.3V, VOUT = 1.25V, ILOAD = 0, COUT = 0.022µF, TA = 25˚C and VEN = VIN. Minimum Input Voltage vs Temperature GND Pin Current vs VIN Unless otherwise specified, VIN DS101291-12 DS101291-13 GND Pin Current at No Load vs Temperature GND Pin Current vs Load DS101291-15 DS101291-14 5 www.national.com LM4121 LM4121- (All Options) Typical Operating Characteristics Short Circuit vs Temperature Unless otherwise specified, VIN = 3.3V, VOUT = 1.25V, ILOAD = 0, COUT = 0.022µF, TA = 25˚C and VEN = VIN. (Continued) Output Impedance vs Frequency DS101291-33 DS101291-17 PSRR vs Frequency Enable Pin Current DS101291-19 DS101291-18 www.national.com 6 LM4121 LM4121- (All Options) Typical Operating Characteristics Start-Up Response Enable Response Unless otherwise specified, VIN = 3.3V, VOUT = 1.25V, ILOAD = 0, COUT = 0.022µF, TA = 25˚C and VEN = VIN. (Continued) DS101291-21 DS101291-22 Load Step Response Load Step Response DS101291-23 DS101291-24 7 www.national.com LM4121 LM4121- (All Options) Typical Operating Characteristics Line Step Response Unless otherwise specified, VIN = 3.3V, VOUT = 1.25V, ILOAD = 0, COUT = 0.022µF, TA = 25˚C and VEN = VIN. (Continued) Noise Spectural Density (0.1Hz-10Hz) DS101291-25 DS101291-26 Noise Spectural Density (10Hz-10kHz) Thermal Hysteresis DS101291-27 DS101291-46 www.national.com 8 LM4121 LM4121-1.25 Typical Operating Characteristics = 1.25V, ILOAD = 0, COUT = 0.022µF, TA = 25˚C and VEN = VIN. Typical Temperature Drift Unless otherwise specified, VIN = 3.3V, VOUT Long Term Drift DS101291-28 DS101291-29 Line Regulation Load Regulation DS101291-30 DS101291-31 9 www.national.com LM4121 LM4121-ADJ Typical Operating Characteristics = 1.2V, ILOAD = 0, COUT = 0.022µF, TA = 25˚C and VEN = VIN. Typical Temperature Drift Unless otherwise specified, VIN = 3.3V, VOUT Long Term Drift DS101291-16 DS101291-36 Dropout Voltage vs Output Error Dropout Voltage vs Load Current DS101291-48 DS101291-47 www.national.com 10 LM4121 LM4121-ADJ Typical Operating Characteristics = 1.2V, ILOAD = 0, COUT = 0.022µF, TA = 25˚C and VEN = VIN. (Continued) Line Regulation Unless otherwise specified, VIN = 3.3V, VOUT Load Regulation DS101291-37 DS101291-38 Adjust Pin Bias Current Change In Reference Voltage vs Output Voltage DS101291-39 DS101291-40 11 www.national.com LM4121 LM4121-ADJ Typical Operating Characteristics = 1.2V, ILOAD = 0, COUT = 0.022µF, TA = 25˚C and VEN = VIN. (Continued) Bode Plot Bode Plot Unless otherwise specified, VIN = 3.3V, VOUT DS101291-41 DS101291-42 www.national.com 12 LM4121 Pin Functions Output (Pin 5): Reference Output. Input (Pin 4):Positive Supply. Ground (Pin 2):Negative Supply or Ground Connection. Enable (Pin 3):Pulled to input for normal operation. Forcing this pin to ground will turn-off the output. REF (Pin 1):REF Pin (1.25V option only). This pin should be left unconnected for 1.25V option. Adj (Pin 1):VOUT Adj Pin (Adjustable option only). See Application Hints section. DS101291-32 Application Hints The standard application circuit for the LM4121 is shown in Figure 1. The output voltage is set with the two feedback resistors, according to the following formula: VOUT = [Vref(1+ R1/R2] − Ibias • R1 Values for R1 and R2 should be chosen to be less than 1 MΩ. Ibias typically flows out of the adjust pin. Values for Vref and Ibias are found in the Electrical Characteristics Spec. table. For best accuracy, be sure to take into account the variation of VREF with input voltage, load and output voltage. The LM4121 is designed to be stable with ceramic output capacitors in the range of 0.022µF to 0.047µF. Note that 0.022µF is the minimum required output capacitor. These capacitors typically have an ESR of about 0.1 to 0.5Ω. Smaller ESR can be tolerated, however larger ESR can not. The output capacitor can be increased to improve load transient response, up to about 1µF. However, values above 0.047µF must be tantalum. With tantalum capacitors, in the 1µF range, a small capacitor between the output and the reference (Adj) pin is required. This capacitor will typically be in the 50pF range. Care must be taken when using output capacitors of 1µF or larger. These application must be thoroughly tested over temperature, line and load. Also, when the LM4121 is used as a controller, with external active components, each application must be carefully tested to ensure a stable design. The adjust pin is sensitive to noise and capacitive loading. The trace to this pin must be as short as possible and the feedback resistiors should be close to this pin. Also, a single point ground to the LM4121 will help ensure good accuracy at high load currents. An input capacitor is typically not required. However, a 0.1µF ceramic can be used to help prevent line transients from entering the LM4121. Larger input capacitors should be tantalum or aluminium. The enable pin is an analog input with very little hysteresis. About 6µA into this pin is required to turn the part on, and it must be taken close to GND to turn the part off (see spec. table for thresholds). There is a minimum slew rate on this pin of about 0.003V/µS to prevent glitches on the output. All of these conditions can easily be met with ordinary CMOS or TTL logic. If the shutdown feature is not required, then this pin can safely be connected directly to the input supply. Floating this pin is not recommended. DS101291-43 FIGURE 1. Standard Application Circuit Printed Circuit Board Layout Consideration The mechanical stress due to PC board mounting can cause the output voltage to shift from its initial value. References in SOT packages are generally less prone to assembly stress than devices in Small Outline (SOIC) package. To reduce the stress-related output voltage shifts, mount the reference on the low flex areas of the PC board such as near to the edge or the corner of the PC board. 13 www.national.com LM4121 Typical Application Circuits Voltage Reference with Negative Output Voltage Reference with Complimentary Output DS101291-6 Two Terminal Constant Current Source DS101291-3 100mA Quasi-LDO Regulator DS101291-7 Precision Voltage Reference with Force and Sense Output DS101291-4 Boosted Output Current with Negative Voltage Reference DS101291-9 DS101291-5 www.national.com 14 LM4121 Typical Application Circuits (Continued) Programmable Current Source Power Supply Splitter DS101291-20 Li + Low Battery Detector DS101291-10 Precision Comparator with Hysteresis DS101291-44 Flasher Circuit DS101291-11 DS101291-45 15 www.national.com LM4121 Precision Micropower Low Dropout Voltage Reference Physical Dimensions inches (millimeters) unless otherwise noted LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation Americas Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: support@nsc.com www.national.com National Semiconductor Europe Fax: +49 (0) 180-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Français Tel: +33 (0) 1 41 91 8790 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Asia Pacific Customer Response Group Tel: 65-2544466 Fax: 65-2504466 Email: ap.support@nsc.com National Semiconductor Japan Ltd. Tel: 81-3-5639-7560 Fax: 81-3-5639-7507 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.