ISL21080 ® Data Sheet July 28, 2009 FN6934.0 300nA NanoPower Voltage References Features The ISL21080 analog voltage references feature low supply voltage operation at ultra-low 310nA typ, 1.5µA max operating current. Additionally, the ISL21080 family features guaranteed initial accuracy as low as ±0.2% and 50ppm/°C temperature coefficient. • Reference Output Voltage . . .1.25V, 1.5V, 2.500V, 3.300V These references are ideal for general purpose portable applications to extend battery life at lower cost. The ISL21080 is provided in the industry standard 3 Ld SOT-23 pinout. • Initial Accuracy: 1.5V . . . . . . . . . . . . . . . . . . . . . . . .±0.5 % • Input Voltage Range - ISL21080-12 (Coming Soon) . . . . . . . . . . . 2.7V to 5.5V - ISL21080-15 . . . . . . . . . . . . . . . . . . . . . . . . 2.7V to 5.5V - ISL21080-25 (Coming Soon) . . . . . . . . . . . 2.7V to 5.5V - ISL21080-33 (Coming Soon) . . . . . . . . . . . 3.5V to 5.5V • Output Voltage Noise . . . . . . . . . 30µVP-P (0.1Hz to 10Hz) The ISL21080 output voltages can be used as precision voltage sources for voltage monitors, control loops, standby voltages for low power states for DSP, FPGA, Datapath Controllers, microcontrollers and other core voltages: 1.25V, 1.5V, 2.5V, and 3.3V. • Supply Current . . . . . . . . . . . . . . . . . . . . . . . . 1.5µA (Max) Pinout • Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Ld SOT-23 • Tempco. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50ppm/°C • Output Current Capability. . . . . . . . . . . . . . . . . . . . . ±7mA • Operating Temperature Range. . . . . . . . . . -40°C to +85°C • Pb-Free (RoHS compliant) ISL21080 (3 LD SOT-23) TOP VIEW Applications • Energy Harvesting Applications VIN 1 3 GND • Wireless Sensor Network Applications • Low Power Voltage Sources for Controllers, FPGA, ASICs or Logic Devices VOUT 2 • Battery Management/Monitoring • Low Power Standby Voltages • Portable Instrumentation • Consumer/Medical Electronics • Wearable Electronics • Lower Cost Industrial and Instrumentation • Power Regulation Circuits • Control Loops and Compensation Networks • LED/Diode Supply 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. FGA is a trademark of Intersil Corporation. Copyright Intersil Americas Inc. 2009. All Rights Reserved All other trademarks mentioned are the property of their respective owners. ISL21080 Ordering Information PART NUMBER (Note) PART MARKING VOUT OPTION (V) GRADE (%) TEMP. RANGE (°C) PACKAGE Tape & Reel (Pb-Free) PKG. DWG. # ISL21080CIH315Z-TK* BCDA 1.5 ±0.5 -40 to +85 3 Ld SOT-23 P3.064 ISL21080CIH312Z-TK* Coming Soon BCNA 1.25 ±0.6 -40 to +85 3 Ld SOT-23 P3.064 ISL21080CIH325Z-TK* Coming Soon BCRA 2.5 ±0.3 -40 to +85 3 Ld SOT-23 P3.064 ISL21080CIH333Z-TK* Coming Soon BCTA 3.3 ±0.2 -40 to +85 3 Ld SOT-23 P3.064 *Please refer to TB347 for details on reel specifications. NOTE: These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. Pin Descriptions PIN NUMBER PIN NAME 1 VIN Input Voltage Connection. 2 VOUT Voltage Reference Output 3 GND Ground Connection 2 DESCRIPTION FN6934.0 July 28, 2009 ISL21080 Absolute Voltage Ratings Thermal Information Max Voltage VIN to GND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to +6.5V VOUT to GND (10s) . . . . . . . . . . . . . . . . . . . . -0.5V to VOUT + 1V ESD Rating Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5500V Machine Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .500V Charged Device Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .>2kV Thermal Resistance (Typical, Note 1) θJA (°C/W) 3 Ld SOT-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202.70 Continuous Power Dissipation (TA = +85°C) . . . . . . . . . . . . . 99mW Storage Temperature Range . . . . . . . . . . . . . . . . . -65°C to +150°C Pb-free Reflow Profile (Note 2). . . . . . . . . . . . . . . . . . see link below http://www.intersil.com/pbfree/Pb-FreeReflow.asp Recommended Operating Conditions Temperature Range (Industrial) . . . . . . . . . . . . . . . . -40°C to +85°C CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and result in failures not covered by warranty. IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typ values are for information purposes only. Unless otherwise noted, all tests are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA NOTES: 1. θJA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details. 2. Post-reflow drift for the ISL21080 devices will range from 100µV to 1.0mV based on experimental results with devices on FR4 double sided boards. The design engineer must take this into account when considering the reference voltage after assembly. Electrical Specifications (ISL21080-15, VOUT = 1.5V) VIN = 3.0V, TA = -40°C to +85°C, IOUT = 0, unless otherwise specified. PARAMETER DESCRIPTION VOUT Output Voltage VOA VOUT Accuracy @ TA = +25°C TC VOUT Output Voltage Temperature Coefficient (Note 4) VIN Input Voltage Range IIN Supply Current ΔVOUT /ΔVIN Line Regulation ΔVOUT/ΔIOUT Load Regulation CONDITIONS MIN TYP MAX 1.5 -0.5 UNIT V +0.5 % 50 ppm/°C 5.5 V 0.31 1.5 µA 2.7 V < VIN < 5.5V 80 250 µV/V Sourcing: 0mA ≤ IOUT ≤ 7mA 10 100 µV/mA Sinking: -7mA ≤ IOUT ≤ 0mA 50 350 µV/mA 2.7 ISC Short Circuit Current TA = +25°C, VOUT tied to GND 50 mA tR Turn-on Settling Time VOUT = ±0.1% with no load 4 ms Ripple Rejection f = 120Hz -30 dB eN Output Voltage Noise 0.1Hz ≤ f ≤ 10Hz 30 µVP-P VN Broadband Voltage Noise 10Hz ≤ f ≤ 1kHz 52 µVRMS Noise Density f = 1kHz 1.1 µV/√Hz ΔVOUT/ΔTA Thermal Hysteresis (Note 5) ΔTA = +165°C 100 ppm ΔVOUT/Δt Long Term Stability (Note 6) TA = +25°C 50 ppm NOTES: 3. Post-assembly x-ray inspection may also lead to permanent changes in device output voltage and should be minimized or avoided. Most inspection equipment will not affect the FGA reference voltage, but if x-ray inspection is required, it is advisable to monitor the reference output voltage to verify excessive shift has not occurred. 4. Over the specified temperature range. Temperature coefficient is measured by the box method whereby the change in VOUT is divided by the temperature range; in this case, -40°C to +85°C = +125°C. 5. Thermal Hysteresis is the change of VOUT measured @ TA = +25°C after temperature cycling over a specified range, ΔTA. VOUT is read initially at TA = +25°C for the device under test. The device is temperature cycled and a second VOUT measurement is taken at +25°C. The difference between the initial VOUT reading and the second VOUT reading is then expressed in ppm. For Δ TA = +125°C, the device under test is cycled from +25°C to +85°C to -40°C to +25°C. 6. Long term drift is logarithmic in nature and diminishes over time. Drift after the first 1000 hours will be approximately 10ppm/√1khrs. 3 FN6934.0 July 28, 2009 ISL21080 Typical Performance Characteristics Curves VOUT = 1.5V, VIN = 3.0V, IOUT = 0mA, TA = +25°C unless otherwise specified. 500 500 UNIT 1 400 400 +85°C 300 300 UNIT 3 IN (nA) IN (nA) UNIT 2 -40°C +25°C 200 200 100 100 0 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5 VIN (V) 0 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5 VIN (V) FIGURE 2. IIN vs VIN OVER-TEMPERATURE FIGURE 1. IIN vs VIN, 3 UNITS 1.50020 150 VOUT (V) (NORMAILIZED TO 1.5V AT VIN = 3V) 125 1.50010 1.50005 UNIT 2 1.50000 UNIT 1 1.49995 UNIT 3 1.49990 VOUT (µV) (NORMALIZED TO VIN = 3.0V) 1.50015 100 75 50 +25°C 25 -25 -50 -75 -100 1.49985 +85°C 0 -40°C -125 1.49980 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5 VIN (V) FIGURE 3. LINE REGULATION, 3 UNITS -150 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5 VIN (V) FIGURE 4. LINE REGULATION OVER-TEMPERATURE 1.5005 1.5004 1.5003 C L = 500pF UNIT 2 ΔV IN = 0.3V 1.5001 UNIT 1 1.5000 1.4999 UNIT 3 1.4998 50mV/DIV VOUT (V) 1.5002 ΔV IN = -0.3V 1.4997 1.4996 1.4995 -40 -30 -20 -10 0 10 20 30 40 VIN (V) 50 60 70 80 FIGURE 5. VOUT vs TEMPERATURE NORMALIZED to +25°C 4 1ms/DIV FIGURE 6. LINE TRANSIENT RESPONSE, WITH CAPACITIVE LOAD FN6934.0 July 28, 2009 ISL21080 Typical Performance Characteristics Curves VOUT = 1.5V, VIN = 3.0V, IOUT = 0mA, TA = +25°C unless otherwise specified. (Continued) 900 C L = 0pF 700 ΔV IN = 0.3V 50mV/DIV ΔVOUT (µV) 500 +25°C 300 100 0 -100 -40°C ΔV IN = -0.3V +85°C -300 -500 -7 -6 -5 -4 -3 -2 -1 SINKING 1ms/DIV 4 5 6 7 SOURCING IL = -50μA 2ms/DIV 1ms/DIV FIGURE 9. LOAD TRANSIENT RESPONSE FIGURE 10. LOAD TRANSIENT RESPONSE 1.52 3.5 NO LOAD 3.0 1.48 2.5 7mA LOAD 1.46 VOLTAGE (V) VOUT (V) 3 IL = 50μA IL = -7mA 1.44 1.40 0.5 2.5 3.0 3.5 VIN (V) 4.0 FIGURE 11. DROPOUT 5 4.5 5.0 5.5 UNIT 1 1.5 1.0 2.0 VIN 2.0 1.42 1.38 1.5 2 FIGURE 8. LOAD REGULATION OVER-TEMPERATURE IL = 7mA 1.50 1 100mV/DIV 500mV/DIV FIGURE 7. LINE TRANSIENT RESPONSE 0 OUTPUT CURRENT 0 0 UNIT 3 UNIT 2 0.5 1.0 1.5 2.0 2.5 3.0 TIME (ms) 3.5 4.0 4.5 5.0 FIGURE 12. TURN-ON TIME FN6934.0 July 28, 2009 ISL21080 Typical Performance Characteristics Curves 160 VOUT = 1.5V, VIN = 3.0V, IOUT = 0mA, TA = +25°C unless otherwise specified. (Continued) 0 NO LOAD NO LOAD 140 -10 -20 1nF 100 PSRR (dB) ZOUT (Ω) 120 80 10nF 60 -30 1nF 10nF -40 -50 40 100nF 20 -60 100nF 0 10 100 1k 10k FREQUENCY (Hz) 100k -70 1M 10 100 FIGURE 13. ZOUT vs FREQUENCY 1k 10k FREQUENCY (Hz) 1M 100k FIGURE 14. PSRR vs FREQUENCY High Current Application 1.502 1.502 VIN = 5V VIN = 5V 1.500 1.498 VREF (V) VREF (V) 1.500 VIN = 3.5V 1.496 0 5 10 15 20 ILOAD (mA) 25 1.496 1.494 30 35 FIGURE 15. DIFFERENT VIN AT ROOM TEMPERATURE Applications Information FGA Technology The ISL21080 series of voltage references use the floating gate technology to create references with very low drift and supply current. Essentially, the charge stored on a floating gate cell is set precisely in manufacturing. The reference voltage output itself is a buffered version of the floating gate voltage. The resulting reference device has excellent characteristics which are unique in the industry: very low temperature drift, high initial accuracy, and almost zero supply current. Also, the reference voltage itself is not limited by voltage bandgaps or zener settings, so a wide range of reference voltages can be programmed (standard voltage settings are provided, but customer-specific voltages are available). The process used for these reference devices is a floating gate CMOS process, and the amplifier circuitry uses CMOS transistors for amplifier and output transistor circuitry. While providing excellent accuracy, there are limitations in output noise level and load regulation due to the MOS device 6 VIN = 3.5V VIN = 3.3V VIN = 3.3V 1.494 1.492 1.498 1.492 0 5 10 15 20 25 30 35 ILOAD (mA) FIGURE 16. DIFFERENT VIN AT HIGH TEMPERATURE characteristics. These limitations are addressed with circuit techniques discussed in other sections. Nanopower Operation Reference devices achieve their highest accuracy when powered up continuously, and after initial stabilization has taken place. This drift can be eliminated by leaving the power on continuously. The ISL21080 is the first high precision voltage reference with ultra low power consumption that makes it possible to leave power on continuously in battery operated circuits. The ISL21080 consumes extremely low supply current due to the proprietary FGA technology. Supply current at room temperature is typically 350nA, which is 1 to 2 orders of magnitude lower than competitive devices. Application circuits using battery power will benefit greatly from having an accurate, stable reference, which essentially presents no load to the battery. In particular, battery powered data converter circuits that would normally require the entire circuit to be disabled when FN6934.0 July 28, 2009 ISL21080 not in use can remain powered up between conversions as shown in Figure 17. Data acquisition circuits providing 12 bits to 24 bits of accuracy can operate with the reference device continuously biased with no power penalty, providing the highest accuracy and lowest possible long term drift. Other reference devices consuming higher supply currents will need to be disabled in between conversions to conserve battery capacity. Absolute accuracy will suffer as the device is biased and requires time to settle to its final value, or, may not actually settle to a final value as power on time may be short. Table 1 shows an example of battery life in years for ISL21080 in various power on condition with 1.5µA maximum current consumption. TABLE 1. EXAMPLE OF BATTERY LIFE IN YEARS FOR ISL21080 IN VARIOUS POWER ON CONDITIONS WITH 1.5µA MAX CURRENT BATTERY RATING (mAH) CONTINUOUS 50% DUTY CYCLE 10% DUTY CYCLE 40 3 6 30* 225 16.3* 32.6* 163* NOTE: *Typical Li-Ion battery has a shelf life of up to 10 years. VIN = +3.0V 10µF 0.01µF VIN VOUT ISL21080 GND 0.001µF TO 0.01µF REF IN SERIAL BUS ENABLE SCK SDAT 12 TO 24-BIT A/D CONVERTER FIGURE 17. ISL21080 Used as a Low Cost Precision Current Source Using an N-JET and a Nanopower voltage reference, ISL21080, a precision, low cost, high impedance current source can be created. The precision of the current source is largely dependent on the tempco and accuracy of the reference. The current setting resistor contributes less than 20% of the error. Board Mounting Considerations For applications requiring the highest accuracy, board mounting location should be reviewed. Placing the device in areas subject to slight twisting can cause degradation of the accuracy of the reference voltage due to die stresses. It is normally best to place the device near the edge of a board, or the shortest side, as the axis of bending is most limited at that location. 7 Obviously, mounting the device on flexprint or extremely thin PC material will likewise cause loss of reference accuracy. +8V TO 28V ISET = VOUT RSET IL = ISET + IRSET VIN 0.01µF VOUT ISL21080-1.5 VOUT = 1.5V RSET ZOUT > 100MΩ 10kΩ 0.1% 10ppm/°C GND ISY ~ 0.31µA ISET IL AT 0.1% ACCURACY ~150.3µA FIGURE 18. ISL21080 USED AS A LOW COST PRECISION CURRENT SOURCE Board Assembly Considerations FGA references provide high accuracy and low temperature drift but some PC board assembly precautions are necessary. Normal output voltage shifts of 100µV to 1mV can be expected with Pb-free reflow profiles. Precautions should be taken to avoid excessive heat or extended exposure to high reflow temperatures, which may reduce device initial accuracy. Post-assembly x-ray inspection may also lead to permanent changes in device output voltage and should be minimized or avoided. If x-ray inspection is required, it is advisable to monitor the reference output voltage to verify excessive shift has not occurred. If large amounts of shift are observed, it is best to add a shield of thin zinc (300µm) to allow imaging but block x-rays that affect the FGA reference. Noise Performance and Reduction The output noise voltage in a 0.1Hz to 10Hz bandwidth is typically 30µVP-P. This is shown in the plot in the “Typical Performance Characteristics Curves” which begin on page 4. The noise measurement is made with a bandpass filter made of a 1 pole high-pass filter with a corner frequency at 0.1Hz and a 2-pole low-pass filter with a corner frequency at 12.6Hz to create a filter with a 9.9Hz bandwidth. Noise in the 10kHz to 1MHz bandwidth is approximately 400µVP-P with no capacitance on the output, as shown in Figure 19. These noise measurements are made with a 2 decade bandpass filter made of a 1 pole high-pass filter with a corner frequency at 1/10 of the center frequency and 1-pole low-pass filter with a corner frequency at 10 times the center frequency. Figure 19 also shows the noise in the 10kHz to 1MHz band can be reduced to about 50µVP-P using a 0.001µF capacitor on the output. Noise in the 1kHz to 100kHz band can be further reduced using a 0.1µF capacitor on the output, but noise in the 1Hz to 100Hz FN6934.0 July 28, 2009 ISL21080 band increases due to instability of the very low power amplifier with a 0.1µF capacitance load. For load capacitances above 0.001µF, the noise reduction network shown in Figure 20 is recommended. This network reduces noise significantly over the full bandwidth. As shown in Figure 19, noise is reduced to less than 40µVP-P from 1Hz to 1MHz using this network with a 0.01µF capacitor and a 2kΩ resistor in series with a 10µF capacitor. 400 NOISE VOLTAGE (µVP-P) CL = 0 350 CL = 0.001µF 300 CL = 0.1µF CL = 0.01µF AND 10µF + 2kΩ Turn-On Time The ISL21080 devices have ultra-low supply current and thus, the time to bias-up internal circuitry to final values will be longer than with higher power references. Normal turn-on time is typically 7ms. This is shown in Figure 18. Since devices can vary in supply current down to >300nA, turn-on time can last up to about 12ms. Care should be taken in system design to include this delay before measurements or conversions are started. Temperature Coefficient The limits stated for temperature coefficient (tempco) are governed by the method of measurement. The overwhelming standard for specifying the temperature drift of a reference, is to measure the reference voltage at two temperatures, take the total variation, (VHIGH – VLOW), and divide by the temperature extremes of measurement (THIGH – TLOW). The result is divided by the nominal reference voltage (at T = +25°C) and multiplied by 106 to yield ppm/°C. This is the “Box” method for specifying temperature coefficient. 250 200 150 100 50 0 1 10 100 1k 10k 100k FIGURE 19. NOISE REDUCTION VIN = 3.0V 10µF 0.1µF VIN VO ISL21080 GND 2kΩ 0.01µF 10µF FIGURE 20. NOISE REDUCTION NETWORK Typical Application Circuits VIN = 3.0V R = 200Ω 2N2905 VIN ISL21080 VOUT 2.5V/50mA 0.001µF GND FIGURE 21. PRECISION 2.5V 50mA REFERENCE 8 FN6934.0 July 28, 2009 ISL21080 Typical Application Circuits (Continued) 2.7V TO 5.5V 0.1µF 10µF VIN VOUT ISL21080 GND 0.001µF VCC RH VOUT X9119 + SDA 2-WIRE BUS VOUT SCL VSS – (BUFFERED) RL FIGURE 22. 2.5V FULL SCALE LOW-DRIFT 10-BIT ADJUSTABLE VOLTAGE SOURCE 2.7V TO 5.5V 0.1µF 10µF VIN VOUT ISL21080 + VOUT SENSE – LOAD GND FIGURE 23. KELVIN SENSED LOAD 9 FN6934.0 July 28, 2009 ISL21080 Small Outline Transistor Plastic Packages (SOT23-3) 0.20 (0.008) M P3.064 VIEW C C 3 LEAD SMALL OUTLINE TRANSISTOR PLASTIC PACKAGE CL b INCHES SYMBOL 6 5 4 CL CL E1 E 1 2 3 e e1 D C CL A A2 A1 WITH b b1 MILLIMETERS MAX MIN MAX NOTES A 0.035 0.044 0.89 1.12 - A1 0.001 0.004 0.013 0.10 - A2 0.035 0.037 0.88 0.94 - b 0.015 0.020 0.37 0.50 - b1 0.012 0.018 0.30 0.45 - c 0.003 0.007 0.085 0.18 6 c1 0.003 0.005 0.08 0.13 6 D 0.110 0.120 2.80 3.04 3 E 0.083 0.104 2.10 2.64 - E1 0.047 0.055 1.20 1.40 3 SEATING PLANE e 0.0374 Ref 0.95 Ref - -C- e1 0.0748 Ref 1.90 Ref - L - 0.10 (0.004) C PLATING MIN c c1 0.016 0.21 0.41 4 L1 0.024 Ref 0.60 Ref - L2 0.010 Ref 0.25 Ref - N 3 3 5 R 0.004 - 0.10 - - R1 0.004 0.010 0.10 0.25 - a 0° 8° 0° 8° Rev. 1 11/06 BASE METAL NOTES: 1. Dimensioning and tolerance per ASME Y14.5M-1994. 4X θ1 2. Package conforms to EIAJ SC-74 and JEDEC MO178AB. 3. Dimensions D and E1 are exclusive of mold flash, protrusions, or gate burrs. R1 4. Footlength L measured at reference to gauge plane. R 5. “N” is the number of terminal positions. GAUGE PLANE SEATING PLANE L C L1 4X θ1 α L2 6. These Dimensions apply to the flat section of the lead between 0.08mm and 0.15mm from the lead tip. 7. Controlling dimension: MILLIMETER. Converted inch dimensions are for reference only 8. Die is facing up for mold die and trim-form. VIEW C All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems. Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 10 FN6934.0 July 28, 2009