19-1203; Rev 0; 4/97 1ppm/°C, Low-Noise, +2.5V/+4.096V/+5V Voltage References ____________________________Features ♦ Ultra-Low, 1ppm/°C Max Tempco ♦ Very Low, 1.5µVp-p Noise (0.1Hz to 10Hz) (MAX6325) ♦ ±0.02% Initial Accuracy (MAX6350) ♦ ±15mA Output Source and Sink Current ♦ Low, 18mW Power Consumption (MAX6325) ♦ Industry-Standard Pinout ♦ Optional Noise Reduction and Voltage Trim ♦ Excellent Transient Response ♦ 8-Pin SO Package Available ♦ Low, 30ppm/1000h Long-Term Stability ♦ Stable for All Capacitive Loads ________________________Applications High-Resolution Analog-to-Digital and Digital-to-Analog Converters ______________Ordering Information PART TEMP. RANGE PINPACKAGE MAX TEMPCO (ppm/°C) 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C -55°C to +125°C 8 Plastic DIP 8 SO 8 Plastic DIP 8 SO 8 CERDIP 1.0 1.0 1.5 1.5 2.5 High-Accuracy Reference Standard High-Accuracy Industrial and Process Control Digital Voltmeters ATE Equipment Precision Current Sources Ordering Information continued at end of data sheet. __________Typical Operating Circuit IN OUT 2.2µF * NR __________________Pin Configuration TOP VIEW 8V TO 36V INPUT MAX6325 MAX6341 MAX6350 MAX6325CPA MAX6325CSA MAX6325EPA MAX6325ESA MAX6325MJA REFERENCE OUT I.C. 1 IN 2 NR 3 TRIM 2.2µF * MAX6325 MAX6341 MAX6350 GND 4 8 I.C. 7 I.C. 6 OUT 5 TRIM GND DIP/SO *OPTIONAL I.C. = INTERNALLY CONNECTED; DO NOT USE ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800 MAX6325/MAX6341/MAX6350 _______________General Description The MAX6325/MAX6341/MAX6350 are low-noise, precision voltage references with extremely low, 0.5ppm/°C typical temperature coefficients and excellent, ±0.02% initial accuracy. These devices feature buried-zener technology for lowest noise performance. Load-regulation specifications are guaranteed for source and sink currents up to 15mA. Excellent line and load regulation and low output impedance at high frequencies make them ideal for high-resolution data-conversion systems up to 16 bits. The MAX6325 is set for a 2.500V output, the MAX6341 is set for a 4.096V output, and the MAX6350 is set for a 5.000V output. All three provide for the option of external trimming and noise reduction. MAX6325/MAX6341/MAX6350 1ppm/°C, Low-Noise, +2.5V/+4.096V/+5V Voltage References ABSOLUTE MAXIMUM RATINGS (Voltages Referenced to GND) IN ................................................................................-0.3V to 40V OUT, TRIM..................................................................-0.3V to 12V NR.................................................................................-0.3V to 6V OUT Short Circuit to GND Duration (VIN ≤ 12V)..........Continuous OUT Short Circuit to GND Duration (VIN ≤ 40V) ....................5sec OUT Short Circuit to IN Duration (VIN ≤ 12V) ..............Continuous Continuous Power Dissipation (TA = +70°C) Plastic DIP (derate 9.09mW/°C above +70°C)................727mW SO (derate 5.88mW/°C above +70°C) ............................471mW CERDIP (derate 8.00mW/°C above +70°C) ....................640mW Operating Temperature Ranges MAX63_ _ C_ A.......................................................0°C to +70°C MAX63_ _ E_ A ....................................................-40°C to +85°C MAX63_ _ MJA ..................................................-55°C to +125°C Storage Temperature Range ..............................-65°C to +150°C Lead Temperature (soldering, 10sec)...............................+300°C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS—MAX6325 (VIN = 10V, IOUT = 0mA, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER Input Voltage Range Output Voltage Output Voltage Temperature Coefficient (Note 1) SYMBOL CONDITIONS VIN VOUT TCVOUT MAX6325 Turn-On Settling Time Output Noise Voltage (Note 3) Temperature Hysteresis Long-Term Stability 2 ∆VOUT / t 2.501 V 1.0 1.5 MAX6325MJA M 1.0 2.5 +25°C 10 18 C 30 E 35 M 45 +25°C IIN en V 2.500 0.5 ∆VOUT / ∆IOUT tON UNITS 36 0.75 ∆VOUT / ∆VIN ∆VOUT 2.499 MAX E Sinking: -15mA ≤ IOUT ≤ 0mA Trim-Adjustment Range +25°C TYP C Sourcing: 0mA ≤ IOUT ≤ 15mA Supply Current 8 MAX6325C_A 10V ≤ VIN ≤ 36V Load Regulation (Note 2) MIN MAX6325E_A 8V ≤ VIN ≤ 10V Line Regulation (Note 2) TA C, E, M 2 C 5 ppm/°C ppm/V 7 E 8 M 10 C 1 6 E 1 7 M 3 15 C 1 6 E 1 7 M 10 30 +25°C 1.8 2.7 C, E, M 3.0 ±15 ±25 ppm/mA mA Figure 1 C, E, M To ±0.01% of final value +25°C 5 µs 0.1Hz ≤ f ≤ 10Hz +25°C 1.5 µVp-p 10Hz ≤ f ≤ 1kHz +25°C 1.3 (Note 4) +25°C 20 ppm +25°C 30 ppm/ 1000h _______________________________________________________________________________________ mV 2.8 µVRMS 1ppm/°C, Low-Noise, +2.5V/+4.096V/+5V Voltage References (VIN = 10V, IOUT = 0mA, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER Input Voltage Range Output Voltage SYMBOL VOUT Output Voltage Temperature Coefficient (Note 1) CONDITIONS VIN TCVOUT MAX6341 Output Noise Voltage (Note 3) en Temperature Hysteresis Long-Term Stability ∆VOUT / t 4.097 V 1.0 1.5 MAX6341MJA M 1.0 2.5 +25°C 10 18 C 30 E 35 M 45 +25°C ∆VOUT / ∆IOUT tON V 4.096 0.5 IIN Turn-On Settling Time UNITS 36 0.75 ∆VOUT / ∆VIN ∆VOUT 4.095 MAX E Sinking: -15mA ≤ IOUT ≤ 0mA Trim-Adjustment Range +25°C TYP C Sourcing: 0mA ≤ IOUT ≤ 15mA Supply Current 8 MAX6341E_A 10V ≤ VIN ≤ 36V Load Regulation (Note 2) MIN MAX6341C_A 8V ≤ VIN ≤ 10V Line Regulation (Note 2) TA C, E, M 2 C 5 ppm/°C ppm/V 7 E 8 M 10 C 1 6 E 1 7 M 3 9 C 1 6 E 1 7 M 7 18 +25°C 1.9 C, E, M 2.9 3.2 ±24 ±40 ppm/mA mA Figure 1 C, E, M mV To ±0.01% of final value +25°C 8 µs 0.1Hz ≤ f ≤ 10Hz +25°C 2.4 µVp-p 10Hz ≤ f ≤ 1kHz +25°C 2.0 (Note 4) +25°C 20 ppm +25°C 30 ppm/ 1000h 4.0 µVRMS _______________________________________________________________________________________ 3 MAX6325/MAX6341/MAX6350 ELECTRICAL CHARACTERISTICS—MAX6341 MAX6325/MAX6341/MAX6350 1ppm/°C, Low-Noise, +2.5V/+4.096V/+5V Voltage References ELECTRICAL CHARACTERISTICS—MAX6350 (VIN = 10V, IOUT = 0mA, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER Input Voltage Range Output Voltage Output Voltage Temperature Coefficient (Note 1) SYMBOL CONDITIONS VIN VOUT TCVOUT MAX6350 Output Noise Voltage (Note 3) E 0.75 1.5 M 1.0 2.5 +25°C 10 18 Temperature Hysteresis Long-Term Stability ∆VOUT / t C 30 E 35 M 45 +25°C IIN en V MAX6350E_A ∆VOUT / ∆IOUT ton V 1.0 ∆VOUT / ∆VIN ∆VOUT UNITS 36 5.001 Sinking: -15mA ≤ IOUT ≤ 0mA Turn-On Settling Time 4.999 MAX 0.5 Sourcing: 0mA ≤ IOUT ≤ 15mA Trim-Adjustment Range +25°C TYP 5.000 10V ≤ VIN ≤ 36V Supply Current 8 C 8V ≤ VIN ≤ 10V Load Regulation (Note 2) MIN MAX6350C_A MAX6350MJA Line Regulation (Note 2) TA C, E, M 2 C 5 ppm/°C ppm/V 7 E 8 M 10 C 1 6 E 1 7 M 2 9 C 1 6 E 1 7 M 6 15 +25°C 2.0 3.0 C, E, M 3.3 ±50 mA Figure 1 C, E, M To ±0.01% of final value +25°C 10 µs 0.1Hz ≤ f ≤ 10Hz +25°C 3.0 µVp-p 10Hz ≤ f ≤ 1kHz +25°C 2.5 (Note 4) +25°C 20 ppm 30 ppm/ 1000h +25°C ±30 ppm/mA mV 5.0 µVRMS Note 1: Temperature coefficient is measured by the box method; i.e., the maximum ∆VOUT is divided by ∆T x VOUT. Note 2: Line regulation (∆VOUT / (VOUT x ∆VIN)) and load regulation (∆VOUT / (VOUT x ∆IOUT)) are measured with pulses and do not include output voltage changes due to die-temperature changes. Note 3: Noise specifications are 100% tested for the 10Hz to 1kHz bandwidth. Production testing in the 0.1Hz to 10Hz bandwidth is available upon request. Note 4: Temperature hysteresis is specified at TA = +25°C by measuring VOUT before and after changing temperature by +25°C using the plastic DIP package. 4 _______________________________________________________________________________________ 1ppm/°C, Low-Noise, +2.5V/+4.096V/+5V Voltage References MAX6341 NORMALIZED OUTPUT VOLTAGE vs. TEMPERATURE 200 0.5 100 0 0 -0.5 -100 -1.0 -200 0.5 125 0 0 -0.5 -1.5 -55 -35 -15 5 25 45 -125 -1.0 -55 -35 -15 -300 65 85 105 125 ∆VOUT (mV) 1.0 250 1.0 5 -250 65 85 105 125 25 45 160 0.3 120 0.2 80 0.1 40 0 0 -0.1 -40 -0.2 -80 -0.3 -120 -0.4 -55 -35 -15 -160 65 85 105 125 25 45 MAX6341 CHANGE IN OUTPUT VOLTAGE vs. OUTPUT CURRENT MAX6325 CHANGE IN OUTPUT VOLTAGE vs. OUTPUT CURRENT 150 100 -100 100 ∆VOUT (µV) ∆VOUT (µV) TA = +85°C TA = +25°C 0 TA = -40°C TA = +25°C -300 10 20 30 40 TA = +85°C -250 -40 -30 -20 -10 IOUT (mA) 0 10 20 30 -40 -30 -20 -10 40 CHANGE IN OUTPUT VOLTAGE vs. INPUT VOLTAGE 40 30 20 10 0 2.6 MAX6350 2.4 MAX6341 MAX6325 2.2 2.0 1.8 1.6 2.5 MAX6350 MAX6341 2.0 MAX6325 1.0 1.0 5 10 15 20 VIN (V) 25 30 35 40 40 3.0 1.2 -20 30 1.5 1.4 -10 20 3.5 MAX6325-08 2.8 SUPPLY CURRENT (mA) 50 10 SUPPLY CURRENT vs. TEMPERATURE SUPPLY CURRENT vs. SUPPLY VOLTAGE 3.0 MAX6325-04 60 0 IOUT (mA) IOUT (mA) SUPPLY CURRENT (mA) 0 TA = +25°C -50 -200 -300 -40 -30 -20 -10 TA = -40°C -150 -200 -400 0 -100 -100 -200 50 MAX6325-09 TA = -40°C MAX6325-05 200 MAX6325-06 MAX6325-07 TA = +85°C 200 0 5 MAX6350 CHANGE IN OUTPUT VOLTAGE vs. OUTPUT CURRENT 100 ∆VOUT (µV) 200 0.4 TEMPERATURE (°C) 200 ∆VOUT (ppm) 240 0.5 TEMPERATURE (°C) 300 280 0.6 TEMPERATURE (°C) 300 0 MAX6325 03 0.7 375 ∆VOUT (ppm) 300 ∆VOUT (mV) ∆VOUT (mV) 1.5 MAX6325 -02 1.5 400 ∆VOUT (ppm) MAX6325 -01 2.0 MAX6325 NORMALIZED OUTPUT VOLTAGE vs. TEMPERATURE ∆VOUT (ppm) MAX6350 NORMALIZED OUTPUT VOLTAGE vs. TEMPERATURE 0 5 10 15 20 25 30 SUPPLY VOLTAGE (V) 35 40 -55 -35 -15 5 25 45 65 85 105 125 TEMPERATURE (°C) _______________________________________________________________________________________ 5 MAX6325/MAX6341/MAX6350 __________________________________________Typical Operating Characteristics (VIN = 10V, IOUT = 0mA, TA = +25°C, unless otherwise noted.) ____________________________Typical Operating Characteristics (continued) (VIN = 10V, IOUT = 0mA, TA = +25°C, unless otherwise noted.) MAX6341 OUTPUT NOISE-VOLTAGE DENSITY vs. FREQUENCY CNR = 0µF 35 30 25 20 CNR = 1µF 15 10 5 70 CNR = 0µF 60 50 40 30 CNR = 1µF 20 10 0 0 10 100 1k 100 1k MAX6325-17 30 CNR = 1µF 20 10 10 100 MAX6325-18 COUT = CNR = 0µF VOUT, 1µV/div VOUT, 1µV/div VOUT, 0.5µV/div 1sec/div RIPPLE REJECTION vs. FREQUENCY (CNR = 0µF) RIPPLE REJECTION (dB) ISINK = 5mA 100 MAX6341 MAX6350 80 ISOURCE = 5mA 85 MAX6350 80 75 70 65 60 60 1M MAX6325 MAX6341 90 RIPPLE REJECTION (dB) MAX6325 90 95 MAX6325-14 120 MAX6325-13 1 10k MAX6350 0.1Hz to 10Hz NOISE RIPPLE REJECTION vs. FREQUENCY (CNR = 1µF) 10 1k FREQUENCY (Hz) 70 6 40 1sec/div 110 1k 10k 100k FREQUENCY (Hz) 50 10k COUT = CNR = 0µF OUTPUT IMPEDANCE vs. FREQUENCY 100 60 MAX6325-16 1sec/div 10 CNR = 0µF 70 MAX6341 0.1Hz to 10Hz NOISE COUT = CNR = 0µF 0.01 80 FREQUENCY (Hz) MAX6325 0.1Hz to 10Hz NOISE 100 90 0 10 10k FREQUENCY (Hz) 0.1 100 MAX6325-12 80 10 100 1k FREQUENCY (Hz) 10k 10 100 1k FREQUENCY (Hz) _______________________________________________________________________________________ 10k MAX6325-15 40 90 MAX6325-11 45 OUTPUT NOISE DENSITY (nV/√ Hz) MAX6325-10 OUTPUT NOISE DENSITY (nV/√ Hz) 50 MAX6350 OUTPUT NOISE-VOLTAGE DENSITY vs. FREQUENCY OUTPUT NOISE DENSITY (nV/√ Hz) MAX6325 OUTPUT NOISE-VOLTAGE DENSITY vs. FREQUENCY OUTPUT IMPEDANCE (Ω) MAX6325/MAX6341/MAX6350 1ppm/°C, Low-Noise, +2.5V/+4.096V/+5V Voltage References 1ppm/°C, Low-Noise, +2.5V/+4.096V/+5V Voltage References (VIN = 10V, IOUT = 0mA, TA = +25°C, unless otherwise noted.) LOAD-TRANSIENT RESPONSE (SOURCING) LOAD-TRANSIENT RESPONSE (SINKING) MAX6325-19 MAX6325-20 0mA A 10mA A -10mA 0mA B B 2µs/div 2µs/div A: IOUT, 10mA/div (SINKING) B: VOUT, 500µV/div A: IOUT, 10mA/div (SOURCING) B: VOUT, 500µV/div MAX6325 TURN-ON AND TURN-OFF TRANSIENT RESPONSE LOAD-TRANSIENT RESPONSE MAX6325-21 MAX6325-26 -10mA A +10V A +10mA 0V B B VIN = 10V COUT = CNR = 0µF CIN = COUT = CNR = 0µF 1µs/div 1µs/div A: IOUT (±10mA SOURCE AND SINK), 20mA/div, AC COUPLED B: VOUT, 20mV/div, AC COUPLED A: B: VIN, 10V/div VOUT, 1V/div MAX6350 TURN-ON AND TURN-OFF TRANSIENT RESPONSE MAX6341 TURN-ON AND TURN-OFF TRANSIENT RESPONSE MAX6325-27 MAX6325-25 +10V A +10V A 0V 0V B B CIN = COUT = CNR = 0µF CIN = COUT = CNR = 0µF 1µs/div 1µs/div A: VIN, 10V/div B: VOUT, 1V/div A: VIN, 10V/div B: VOUT, 1V/div _______________________________________________________________________________________ 7 MAX6325/MAX6341/MAX6350 ____________________________Typical Operating Characteristics (continued) MAX6325/MAX6341/MAX6350 1ppm/°C, Low-Noise, +2.5V/+4.096V/+5V Voltage References _____________________Pin Description PIN NAME 1, 7, 8 I.C. Internally Connected. Do not use. 2 IN Positive Power-Supply Input NR Noise Reduction. Optional capacitor connection for wideband noise reduction. Leave open if not used (Figure 2). 3 FUNCTION 4 GND Ground 5 TRIM External Trim Input. Allows ±1% output adjustment (Figure 1). Leave open if not used. 6 OUT Voltage Reference Output Noise Reduction To augment wideband noise reduction, add a 1µF capacitor to the NR pin (Figure 2). Larger values do not improve noise appreciably (see Typical Operating Characteristics). Noise in the power-supply input can affect output noise, but can be reduced by adding an optional bypass capacitor to the IN pin and GND. Bypassing The MAX6325/MAX6341/MAX6350 are stable with capacitive load values from 0µF to 100µF, for all values of load current. Adding an output bypass capacitor can help reduce noise and output glitching caused by load transients. __________Applications Information Negative Regulator _______________Detailed Description Temperature Stability The MAX6325/MAX6341/MAX6350 are highly stable, low-noise voltage references that use a low-power temperature-compensation scheme to achieve laboratorystandard temperature stability. This produces a nearly flat temperature curve, yet does not require the power associated with heated references. The output voltage can be trimmed a minimum of 0.6% by connecting a 10kΩ potentiometer between OUT and GND, and connecting its tap to the TRIM pin, as shown in Figure 1. The external trimming does not affect temperature stability. Figure 3 shows how both a +5V and -5V precision reference can be obtained from a single, unregulated +5V supply. A MAX681 generates approximately ±9V to operate the MAX6350 reference and MAX400 inverting amplifier. The +5V is inverted by the ultra-low offset MAX400 op amp. Resistor R1 is optional, and may be used to trim the ±5V references. R2 and R4 should be matched, both in absolute resistance and temperature coefficient. R3 is optional, and is adjusted to set the -5V reference. 8V TO 36V INPUT 8V TO 36V INPUT IN IN REFERENCE OUT NR MAX6325 MAX6341 MAX6350 * TRIM GND REFERENCE OUT OUT OUT 10k NR 1µF MAX6325 MAX6341 MAX6350 TRIM GND *OPTIONAL Figure 1. Output Voltage Adjustment 8 Figure 2. Noise-Reduction Capacitor _______________________________________________________________________________________ 1ppm/°C, Low-Noise, +2.5V/+4.096V/+5V Voltage References 3.3µF C1+ VCC V+ +REFERENCE OUT IN C1- OUT R2 100k MAX865 3.3µF C1 2.2µF C2+ C2- GND MAX6350 V- NR TRIM GND 0.1µF R1 10k C3 2.2µF C2 1µF 2.2µF R3 1k C4 1µF R4 100k MAX400 0.1µF -REFERENCE OUT Figure 3. +5V and -5V References from a Single +5V Supply _Ordering Information (continued) PART MAX6341CPA MAX6341CSA MAX6341EPA MAX6341ESA MAX6341MJA MAX6350CPA MAX6350CSA MAX6350EPA MAX6350ESA MAX6350MJA TEMP. RANGE PINPACKAGE MAX. TEMPCO (ppm/°C) 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C -55°C to +125°C 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C -55°C to +125°C 8 Plastic DIP 8 SO 8 Plastic DIP 8 SO 8 CERDIP 8 Plastic DIP 8 SO 8 Plastic DIP 8 SO 8 CERDIP 1.0 1.0 1.5 1.5 2.5 1.0 1.0 1.5 1.5 2.5 ___________________Chip Information TRANSISTOR COUNT: 435 _______________________________________________________________________________________ 9 MAX6325/MAX6341/MAX6350 +5V INPUT SOICN.EPS ________________________________________________________Package Information PDIPN.EPS MAX6325/MAX6341/MAX6350 1ppm/°C, Low-Noise, +2.5V/+4.096V/+5V Voltage References 10 ______________________________________________________________________________________ 1ppm/°C, Low-Noise, +2.5V/+4.096V/+5V Voltage References CDIPS.EPS ______________________________________________________________________________________ 11 MAX6325/MAX6341/MAX6350 ___________________________________________Package Information (continued) MAX6325/MAX6341/MAX6350 1ppm/°C, Low-Noise, +2.5V/+4.096V/+5V Voltage References NOTES Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 12 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600 © 1997 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.