LM4125 Precision Micropower Low Dropout Voltage Reference General Description Features The LM4125 is a precision low power low dropout bandgap voltage reference with up to 5 mA output current source and sink capability. n n n n n n n n n This series reference operates with input voltages as low as 2V and up to 6V consuming 160 µA (Typ.) supply current. In power down mode, device current drops to less than 2 µA. The LM4125 comes in two grades (A and Standard) and three voltage options for greater flexibility. 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 dropout voltage, low supply current and powerdown capability of the LM4125 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 LM4125 is available in a standard 5-pin SOT-23 package. Small SOT23-5 package Low dropout voltage: 120 mV Typ @ 1 mA High output voltage accuracy: 0.2% ± 5 mA Source and Sink current output: Supply current: 160 µA Typ. Low Temperature Coefficient: 50 ppm/˚C Fixed output voltages: 2.048, 2.5,and 4.096 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 Connection Diagram 20069802 Refer to the Ordering Information Table in this Data Sheet for Specific Part Number SOT23-5 Surface Mount Package © 2003 National Semiconductor Corporation DS200698 www.national.com LM4125 Precision Micropower Low Dropout Voltage Reference November 2003 LM4125 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 LM4125 Supplied as 1000 Units, Tape and Reel LM4125 Supplied as 3000 Units, Tape and Reel Top Marking LM4125AIM5-2.0 LM4125AIM5X-2.0 R80A LM4125AIM5-2.5 LM4125AIM5X-2.5 R81A LM4125AIM5-4.1 LM4125AIM5X-4.1 R82A LM4125IM5-2.0 LM4125IM5X-2.0 R80B LM4125IM5-2.5 LM4125IM5X-2.5 R81B LM4125IM5-4.1 LM4125IM5X-4.1 R82B 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: 80 = 2.048V Voltage Option 81 = 2.500V Voltage Option 82 = 4.096V Voltage Option Fourth Field: A-B = Initial Reference Voltage Tolerance A = ± 0.2% B = ± 0.5% www.national.com 2 Lead Temperature: (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 −0.3V to 8V Output Short-Circuit Duration Indefinite Power Dissipation ESD Susceptibility (Note 3) Human Body Model Machine Model +260˚C Vapor Phase (60 sec.) +215˚C Infrared (15 sec.) +220˚C Operating Range (Note 1) Storage Temperature Range −65˚C to +150˚C 350 mW Ambient Temperature Range −40˚C to +85˚C 2 kV 200V Junction Temperature Range −40˚C to +125˚C Power Dissipation (TA = 25˚C) (Note 2): MA05B package − θJA Soldering, (10 sec.) 280˚C/W Electrical Characteristics LM4125-2.048V and 2.5V 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 Max (Note 5) Units Output Voltage Initial Accuracy LM4125A-2.048 LM4125A-2.500 ± 0.2 % LM4125-2.048 LM4125-2.500 ± 0.5 % 14 50 ppm/˚c 0.0007 0.008 0.01 %/V 0 mA ≤ ILOAD ≤ 1 mA 0.03 0.08 0.17 1 mA ≤ ILOAD ≤ 5 mA 0.01 0.04 0.1 −1 mA ≤ ILOAD ≤ 0 mA 0.04 0.12 −5 mA ≤ ILOAD ≤ −1 mA 0.01 Parameter Conditions TCVOUT/˚C Temperature Coefficient −40˚C ≤ TA ≤ +125˚C ∆VOUT/∆VIN Line Regulation 3.3V ≤ VIN ≤ 6V ∆VOUT/∆ILOAD VIN−VOUT Load Regulation Dropout Voltage (Note 6) Min (Note 5) Typ (Note 4) ILOAD = 0 mA 45 65 100 ILOAD = +1 mA 120 150 200 ILOAD = +5 mA 180 210 300 VN Output Noise Voltage 0.1 Hz to 10 Hz (Note 8) 10 Hz to 10 kHz 20 36 IS Supply Current 160 VIN = 3.3V, VOUT = 0 ISC Short Circuit Current Hyst Thermal Hysteresis (Note 7) %/mA mV µVPP µVPP 257 290 µA 15 6 VIN = 6V, VOUT = 0 30 17 6 −40˚C ≤ TA ≤ 125˚C 30 0.5 3 mA mV/V www.national.com LM4125 Absolute Maximum Ratings LM4125 Electrical Characteristics LM4125-2.048V and 2.5V 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. (Continued) Symbol ∆VOUT Parameter Long Term Stability (Note 9) Conditions Min (Note 5) 1000 hrs. @ 25˚C Typ (Note 4) Max (Note 5) 100 Units ppm Electrical Characteristics LM4125-4.096V Unless otherwise specified VIN = 5V, 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 Conditions Min (Note 5) Typ (Note 4) Output Voltage Initial Accuracy LM4125A-4.096 % ppm/˚c 0.0007 0.008 0.01 %/V 0 mA ≤ ILOAD ≤ 1 mA 0.03 0.08 0.17 1 mA ≤ ILOAD ≤ 5 mA 0.01 0.04 0.1 −1 mA ≤ ILOAD ≤ 0 mA 0.04 0.12 −5 mA ≤ ILOAD ≤ −1 mA 0.01 ∆VOUT/∆VIN Line Regulation 5V ≤ VIN ≤ 6V VN IS Dropout Voltage (Note 6) % 50 −40˚C ≤ TA ≤ +125˚C VIN−VOUT ± 0.2 ± 0.5 Temperature Coefficient Load Regulation Units 14 LM4125-4.096 TCVOUT/˚C ∆VOUT/∆ILOAD Max (Note 5) ILOAD = 0 mA 45 65 100 ILOAD = +1 mA 120 150 200 ILOAD = +5 mA 180 210 300 %/mA mV Output Noise Voltage 0.1 Hz to 10 Hz (Note 8) 10 Hz to 10 kHz 20 µVPP 36 µVPP Supply Current 160 VOUT = 0 257 290 µA 15 6 30 ISC Short Circuit Current Hyst Thermal Hysteresis (Note 7) −40˚C ≤ TA ≤ 125˚C 0.5 mV/V ∆VOUT Long Term Stability (Note 9) 1000 hrs. @ 25˚C 100 ppm VIN = 6V, VOUT = 0 17 6 www.national.com 4 mA 30 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: Dropout voltage is the differential voltage between VOUT and VIN at which VOUT changes ≤ 1% from VOUT at VIN = 3.3V for 2.0V, 2.5V and 5V for 4.1V. A parasitic diode exists between input and output pins; it will conduct if VOUT is pulled to a higher voltage than VIN. Note 7: Thermal hysteresis is defined as the change in +25˚C output voltage before and after exposing the device to temperature extremes. Note 8: Output noise voltage is proportional to VOUT. VN for other voltage option is calculated using (VN(1.8V)/1.8) * VOUT. VN (2.5V) = (36µVPP/1.8) * 2.5 = 46µVPP. Note 9: Long term stability is change in VREF at 25˚C measured continuously during 1000 hrs. 5 www.national.com LM4125 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. LM4125 LM4125 Typical Operating Characteristics Unless otherwise specified, VIN = 3.3V, VOUT = 2.5V, ILOAD = 0, COUT = 0.022µF and TA = 25˚C. Long Term Drift Typical Temperature Drift 20069812 20069813 Short Circuit Current vs Temperature Dropout Voltage vs Output Error 20069814 20069815 Dropout Voltage vs Load Current Load Regulation 20069833 www.national.com 20069818 6 GND Pin Current at No Load vs Temperature GND Pin Current 20069819 20069821 GND Pin Current vs Load 0.1Hz to 10Hz output Noise 20069823 20069822 Output Impedance vs Frequency PSRR vs Frequency 20069824 20069825 7 www.national.com LM4125 LM4125 Typical Operating Characteristics Unless otherwise specified, VIN = 3.3V, VOUT = 2.5V, ILOAD = 0, COUT = 0.022µF and TA = 25˚C. (Continued) LM4125 LM4125 Typical Operating Characteristics Unless otherwise specified, VIN = 3.3V, VOUT = 2.5V, ILOAD = 0, COUT = 0.022µF and TA = 25˚C. (Continued) Start-Up Response Load Step Response 20069826 20069828 Load Step Response Line Step Response 20069829 20069830 Thermal Hysteresis 20069831 www.national.com 8 Output (Pin 5): Reference Output. Input (Pin 4):Positive Supply. Ground (Pin 2):Negative Supply or Ground Connection. Application Hints The standard application circuit for the LM4125 is shown in Figure 1. It is designed to be stable with ceramic output capacitors in the range of 0.022µF to 0.1µF. 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 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. 20069832 FIGURE 1. INPUT CAPACITOR Noise on the power-supply input can effect the output noise, but can be reduced by using an optional bypass capacitor between the input pin and the ground. An input capacitor is typically not required. However, a 0.1µF ceramic can be used to help prevent line transients from entering the LM4125. Larger input capacitors should be tantalum or aluminium. The typical thermal hysteresis specification is defined as the change in +25˚C voltage measured after thermal cycling. The device is thermal cycled to temperature -40˚C and then measured at 25˚C. Next the device is thermal cycled to temperature +125˚C and again measured at 25˚C. The resulting VOUT delta shift between the 25˚C measurements is thermal hysteresis. Thermal hysteresis is common in preci- 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. 9 www.national.com LM4125 sion references and is induced by thermal-mechanical package stress. Changes in environmental storage temperature, operating temperature and board mounting temperature are all factors that can contribute to thermal hysteresis. Pin Functions LM4125 Typical Application Circuits Voltage Reference with Complimentary Output Voltage Reference with Negative Output 20069806 Precision High Current Low Droput Regulator 20069803 Precision High Current Low Dropout Regulator 20069807 Precision Voltage Reference with Force and Sense Output 20069804 Precision High Current Negative Voltage Regulator 20069809 Programmable Current Source 20069805 20069810 www.national.com 10 LM4125 Typical Application Circuits Power Supply Splitter (Continued) Precision Regulator with Current Limiting Circuit 20069820 20069811 11 www.national.com LM4125 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. 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. BANNED SUBSTANCE COMPLIANCE National Semiconductor certifies that the products and packing materials meet the provisions of the Customer Products Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification (CSP-9-111S2) and contain no ‘‘Banned Substances’’ as defined in CSP-9-111S2. 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