MAX6325/MAX6341/MAX6350 LE AVAILAB 1ppm/C, Low-Noise, +2.5V/+4.096V/+5V Voltage References 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 2.5V output, the MAX6341 is set for a 4.096V output, and the MAX6350 is set for a 5V output. All three provide for the option of external trimming and noise reduction. ____________________________Features Ultra Low, 1ppm/C Max Tempco Very Low, 1.5Vp-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/1000hr Long-Term Stability Stable for All Capacitive Loads 19-1203; Rev 1; 1/01 Ordering Information ________________________Applications High-Resolution Analog-to-Digital and Digital-to-Analog Converters PART TEMP. RANGE PINPACKAGE MAX TEMPCO (ppm/C) 0C to +70C 0C to +70C -40C to +85C -40C to +85C -55C to +125C 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 Functional Diagrams MAX6325CPA MAX6325CSA MAX6325EPA MAX6325ESA MAX6325MJA Ordering Information continued at end of data sheet. PinConfiguration Configuration Pin Typical Operating Circuit TOP VIEW 8V TO 36V INPUT IN OUT 2.2F * NR MAX6325 MAX6341 MAX6350 REFERENCE OUT I.C. 1 IN 2 NR 3 TRIM 2.2F * MAX6325 MAX6341 MAX6350 GND 4 8 I.C. 7 I.C. 6 OUT 5 TRIM GND DIP/SO Pin Configurations appear at end of data sheet. Functional Diagrams continued at end of data sheet. *OPTIONAL UCSP is a trademark of Maxim Integrated Products, Inc. I.C. = INTERNALLY CONNECTED; DO NOT USE For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maximintegrated.com. 19-1203; Rev 1; 1/01 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) ........................5s OUT Short-Circuit to IN Duration (VIN 12V) ..............Continuous Continuous Power Dissipation (TA = +70C) 8-Pin Plastic DIP (derate 9.09mW/C above +70C) ......727mW 8-Pin SO (derate 5.88mW/C above +70C) ...................471mW 8-Pin CERDIP (derate 8.00mW/C above +70C)...........640mW Operating Temperature Ranges MAX63_ _ C_ A.......................................................0C to +70C MAX63_ _ E_ A....................................................-40C to +85C MAX63_ _ MJA ..................................................-55C to +125C Storage Temperature Range ..............................-65C to +150C Lead Temperature (soldering, 10s)...................................+300C 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 = +25C.) PARAMETER Input Voltage Range Output Voltage SYMBOL CONDITIONS MAX UNITS 36 V 2.500 2.501 V C 0.5 1.0 MAX6325E_A E 0.75 1.5 MAX6325MJA M 1.0 2.5 +25C 10 18 VIN VOUT MAX6325 MAX6325C_A Output Voltage Temperature Coefficient (Note 1) TCVOUT 8V VIN 10V Line Regulation (Note 2) VOUT/ VIN VOUT/ IOUT Sinking: -15mA IOUT 0mA Trim-Adjustment Range IIN VOUT Turn-On Settling Time tON Output Noise Voltage (Note 3) en Temperature Hysteresis Long-Term Stability 2 VOUT/t 8 +25C 2.499 TYP C 30 E 35 45 +25C Sourcing: 0mA IOUT 15mA Supply Current MIN M 10V VIN 36V Load Regulation (Note 2) TA C, E, M 2 C 5 ppm/C ppm/V 7 E 8 M 10 C 1 E 1 6 7 M 3 15 C 1 6 E 1 7 M 10 30 +25C 1.8 2.7 C, E, M 3.0 15 ppm/mA mA (Figure 1) C, E, M 25 mV To 0.01% of final value +25C 5 s 0.1Hz f 10Hz +25C 1.5 10Hz f 1kHz +25C 1.3 (Note 4) +25C 20 ppm +25C 30 ppm/ 1000hr Vp-p 2.8 VRMS Maxim Integrated MAX6325/MAX6341/MAX6350 1ppm/C, Low-Noise, +2.5V/+4.096V/+5V Voltage References ELECTRICAL CHARACTERISTICS--MAX6341 (VIN = +10V, IOUT = 0mA, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) PARAMETER Input Voltage Range Output Voltage SYMBOL CONDITIONS TYP MAX UNITS 36 V 4.096 4.097 V C 0.5 1.0 MAX6341E_A E 0.75 1.5 MAX6341MJA M 1.0 2.5 +25C 10 18 VIN VOUT MAX6341 MAX6341C_A Output Voltage Temperature Coefficient (Note 1) TCVOUT 8V VIN 10V Line Regulation (Note 2) VOUT/ VIN VOUT/ IOUT Sinking: -15mA IOUT 0mA Trim-Adjustment Range IIN VOUT Turn-On Settling Time tON Output Noise Voltage (Note 3) en Temperature Hysteresis Long-Term Stability Maxim Integrated VOUT/t C, E, M 8 +25C 4.095 C 30 E 35 45 +25C Sourcing: 0mA IOUT 15mA Supply Current MIN M 10V VIN 36V Load Regulation (Note 2) TA 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 +25C 1.9 2.9 C, E, M 3.2 24 ppm/mA mA (Figure 1) C, E, M 40 mV To 0.01% of final value +25C 8 s 0.1Hz f 10Hz +25C 2.4 10Hz f 1kHz +25C 2.0 (Note 4) +25C 20 ppm +25C 30 ppm/ 1000hr Vp-p 4.0 VRMS 3 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 = +25C.) PARAMETER Input Voltage Range Output Voltage SYMBOL CONDITIONS VIN VOUT MAX6350 TCVOUT Turn-On Settling Time Output Noise Voltage (Note 3) E 0.75 1.5 M 1.0 2.5 +25C 10 Temperature Hysteresis Long-Term Stability VOUT/t 30 E 35 M 45 2 C ppm/C 18 C +25C IIN en V MAX6350MJA VOUT/ IOUT tON V MAX6350E_A VOUT/ VIN VOUT UNITS 36 1.0 Sinking: -15mA IOUT 0mA Trim-Adjustment Range 4.999 MAX 5.001 Sourcing: 0mA IOUT 15mA Supply Current +25C TYP 0.5 10V VIN 36V Load Regulation (Note 2) 8 5.000 8V VIN 10V Line Regulation (Note 2) MIN C MAX6350C_A Output Voltage Temperature Coefficient (Note 1) TA C, E, M 5 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 +25C 2.0 3.0 C, E, M 3.3 50 mA (Figure 1) C, E, M To 0.01% of final value +25C 10 s 0.1Hz f 10Hz +25C 3.0 Vp-p 10Hz f 1kHz +25C 2.5 (Note 4) +25C 20 ppm 30 ppm/ 1000hr +25C 30 ppm/mA mV 5.0 VRMS 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 guaranteed by design. Note 4: Temperature hysteresis is specified at TA = +25C by measuring VOUT before and after changing temperature by +25C, using the plastic DIP package. 4 Maxim Integrated MAX6325/MAX6341/MAX6350 1ppm/C, Low-Noise, +2.5V/+4.096V/+5V Voltage References __________________________________________Typical Operating Characteristics (VIN = +10V, IOUT = 0mA, TA = +25C, unless otherwise noted.) MAX6341 NORMALIZED OUTPUT VOLTAGE vs. TEMPERATURE 200 0.5 100 0 0 250 -0.5 -100 -1.0 -200 0.5 125 0 0 -0.5 -1.5 -55 -35 -15 5 25 45 5 200 0.4 160 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 5 -160 65 85 105 125 25 45 TEMPERATURE (C) CHANGE IN OUTPUT VOLTAGE vs. INPUT VOLTAGE MAX6325 CHANGE IN OUTPUT VOLTAGE vs. OUTPUT CURRENT MAX6341 CHANGE IN OUTPUT VOLTAGE vs. OUTPUT CURRENT 150 MAX6325-06 300 MAX6325-05 MAX6325-04 200 TA = +85C 200 100 30 20 10 50 TA = -40C 0 VOUT (V) VOUT (V) 40 TA = +25C -50 -300 -250 10 15 20 25 30 35 -40 -30 -20 -10 40 10 20 30 -40 -30 -20 -10 40 MAX6350 CHANGE IN OUTPUT VOLTAGE vs. OUTPUT CURRENT 100 TA = +85C TA = -40C -100 -200 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 -40 -30 -20 -10 0 10 IOUT (mA) Maxim Integrated 20 30 40 40 3.0 1.2 -400 30 1.5 1.4 TA = +25C 20 3.5 MAX6325-08 2.8 SUPPLY CURRENT (mA) 200 10 SUPPLY CURRENT vs. TEMPERATURE SUPPLY CURRENT vs. SUPPLY VOLTAGE 3.0 MAX6325-07 300 0 IOUT (mA) IOUT (mA) VIN (V) -300 0 MAX6325-09 5 SUPPLY CURRENT (mA) 0 0 -200 TA = +85C -200 -20 TA = +25C TA = -40C -150 -10 100 -100 -100 0 VOUT (V) 25 45 240 0.5 TEMPERATURE (C) 50 0 -250 65 85 105 125 280 0.6 TEMPERATURE (C) 60 VOUT (ppm) -125 -1.0 -55 -35 -15 -300 65 85 105 125 VOUT (mV) 1.0 MAX6325 03 0.7 375 1.0 VOUT (mV) 300 VOUT (ppm) 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 1ppm/C, Low-Noise, +2.5V/+4.096V/+5V Voltage References ____________________________Typical Operating Characteristics (continued) (VIN = +10V, IOUT = 0mA, TA = +25C, unless otherwise noted.) MAX6341 OUTPUT NOISE-VOLTAGE DENSITY vs. FREQUENCY CNR = 0F 35 30 25 20 CNR = 1F 15 10 5 70 CNR = 0F 60 50 40 30 CNR = 1F 20 10 10 100 1k 100 1k CNR = 0F 70 60 50 40 30 CNR = 1F 20 10 10k 10 100 1k 10k FREQUENCY (Hz) FREQUENCY (Hz) RIPPLE REJECTION vs. FREQUENCY (CNR = 1F) OUTPUT IMPEDANCE vs. FREQUENCY RIPPLE REJECTION vs. FREQUENCY (CNR = 0F) MAX6341 MAX6350 80 10 1 0.1 ISINK = 5mA MAX6325 MAX6341 90 RIPPLE REJECTION (dB) OUTPUT IMPEDANCE () 100 95 MAX6325-14 MAX6325-13 MAX6325 90 100 70 85 MAX6350 80 75 70 65 ISOURCE = 5mA 0.01 60 10 100 1k 10 10k 100 FREQUENCY (Hz) 1k 10k 100k FREQUENCY (Hz) 60 10 1M MAX6325-18 VOUT, 1V/div COUT = CNR = 0F VOUT, 1V/div COUT = CNR = 0F 10k MAX6350 0.1Hz to 10Hz NOISE COUT = CNR = 0F VOUT, 0.5V/div 1k MAX6325-17 MAX6325-16 1s/div 100 FREQUENCY (Hz) MAX6341 0.1Hz to 10Hz NOISE MAX6325 0.1Hz to 10Hz NOISE 6 80 FREQUENCY (Hz) 120 110 90 0 10 10k MAX6325-12 100 0 0 RIPPLE REJECTION (dB) 80 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 1s/div 1s/div Maxim Integrated MAX6325/MAX6341/MAX6350 1ppm/C, Low-Noise, +2.5V/+4.096V/+5V Voltage References ____________________________Typical Operating Characteristics (continued) (VIN = +10V, IOUT = 0mA, TA = +25C, unless otherwise noted.) LOAD-TRANSIENT RESPONSE (SOURCING) LOAD-TRANSIENT RESPONSE (SINKING) MAX6325-19 MAX6325-20 0mA A 10mA A -10mA 0mA B B 2s/div 2s/div A: IOUT, 10mA/div (SINKING) B: VOUT, 500V/div A: IOUT, 10mA/div (SOURCING) B: VOUT, 500V/div MAX6325 TURN-ON AND TURN-OFF TRANSIENT RESPONSE LOAD-TRANSIENT RESPONSE MAX6325-21 MAX6325-22 -10mA A +10mA +10V A 0 B VIN = 10V COUT = CNR = 0F B CIN = COUT = CNR = 0F 1s/div 1s/div A: IOUT (10mA SOURCE AND SINK), 20mA/div, AC COUPLED B: VOUT, 20mV/div, AC COUPLED A: VIN, 10V/div B: VOUT, 1V/div MAX6350 TURN-ON AND TURN-OFF TRANSIENT RESPONSE MAX6341 TURN-ON AND TURN-OFF TRANSIENT RESPONSE MAX6325-24 MAX6325-23 +10V +10V 0 A A 0 B B CIN = COUT = CNR = 0F CIN = COUT = CNR = 0F 1s/div 1s/div A: VIN, 10V/div B: VOUT, 1V/div Maxim Integrated A: VIN, 10V/div B: VOUT, 1V/div 7 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 1F 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 0F to 100F, 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 10k 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 MAX865 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 OUT NR MAX6325 MAX6341 MAX6350 * TRIM GND REFERENCE OUT OUT 10k NR 1F MAX6325 MAX6341 MAX6350 TRIM GND *OPTIONAL Figure 1. Output Voltage Adjustment 8 Figure 2. Noise-Reduction Capacitor Maxim Integrated MAX6325/MAX6341/MAX6350 1ppm/C, Low-Noise, +2.5V/+4.096V/+5V Voltage References +5V INPUT 3.3F C1+ VCC V+ +REFERENCE OUT IN C1- OUT R2 100k MAX865 3.3F C1 2.2F C2+ C2- GND MAX6350 V- NR TRIM GND 0.1F R1 10k C3 2.2F C2 1F 2.2F R3 1k C4 1F R4 100k MAX400 0.1F -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 Maxim Integrated TEMP. RANGE PINPACKAGE MAX. TEMPCO (ppm/C) 0C to +70C 0C to +70C -40C to +85C -40C to +85C -55C to +125C 0C to +70C 0C to +70C -40C to +85C -40C to +85C -55C to +125C 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 1ppm/C, Low-Noise, +2.5V/+4.096V/+5V Voltage References PDIPN.EPS SOICN.EPS ________________________________________________________Package Information 10 Maxim Integrated MAX6325/MAX6341/MAX6350 1ppm/C, Low-Noise, +2.5V/+4.096V/+5V Voltage References CDIPS.EPS ___________________________________________Package Information (continued) 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. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 (c) Maxim Integrated 11 The Maxim logo and Maxim Integrated are trademarks of Maxim Integrated Products, Inc.