19-1139; Rev 4; 1/01 Low-Noise, Precision, +2.5V/+4.096V/+5V Voltage References Features Low 1.0ppm/C Temperature Coefficient Very Low 1.5Vp-p Noise (0.1Hz to 10Hz) 0.02% Initial Accuracy 15mA Output Source and Sink Current Low, 18mW Power Consumption (MAX6225) Industry-Standard Pinout Optional Noise Reduction and Voltage Trim Excellent Transient Response 8-Pin SO Package Available Low 20ppm/1000hr Long-Term Stability Stable for All Capacitive Loads Ordering Information Applications High-Resolution Analog-to-Digital and Digital-to-Analog Converters High-Accuracy Reference Standard High-Accuracy Industrial and Process Control Digital Voltmeters ATE Equipment Precision Current Sources PART TEMP. RANGE PINPACKAGE MAX TEMPCO (ppm/C) MAX6225ACPA 0C to +70C 8 Plastic DIP 2.0 MAX6225BCPA MAX6225ACSA MAX6225BCSA MAX6225AEPA MAX6225BEPA MAX6225AESA MAX6225BESA MAX6225AMJA MAX6225BMJA 0C to +70C 0C to +70C 0C to +70C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -55C to +125C -55C to +125C 8 Plastic DIP 8 SO 8 SO 8 Plastic DIP 8 Plastic DIP 8 SO 8 SO 8 CERDIP 8 CERDIP 5.0 2.0 5.0 3.0 7.0 3.0 7.0 5.0 8.0 Ordering Information continued at end of data sheet. Typical Operating Circuit TOP VIEW 8V TO 36V INPUT IN OUT 2.2F * NR MAX6225 MAX6241 MAX6250 Pin Configuration REFERENCE OUT I.C. 1 IN 2 NR 3 TRIM 2.2F * MAX6225 MAX6241 MAX6250 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 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. 1 MAX6225/MAX6241/MAX6250 General Description The MAX6225/MAX6241/MAX6250 are low-noise, precision voltage references with extremely low 1ppm/C 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 frequency make them ideal for high-resolution data-conversion systems up to 16 bits. The MAX6225 is set for 2.500V output, the MAX6241 is set for 4.096V output, and the MAX6250 is set for 5.000V output. All three provide for the option of external trimming and noise reduction. MAX6225/MAX6241/MAX6250 Low-Noise, Precision, +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 MAX62_ _ _C_ A.....................................................0C to +70C MAX62_ _ _E_ A ..................................................-40C to +85C MAX62_ _ _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--MAX6225 (VIN = +10V, IOUT = 0mA, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) PARAMETER Input Voltage Range Output Voltage Output Voltage Temperature Coefficient (Note 1) SYMBOL CONDITIONS VIN VOUT TCVOUT TYP MAX UNITS 36 V C, E, M 8 +25C 2.499 2.500 2.501 MAX6225B +25C 2.497 2.500 2.503 MAX6225AC_A C 1.0 2.0 MAX6225AE_A E 1.5 3.0 MAX6225AMJA M 2.0 5.0 MAX6225BC_A C 2.5 5.0 MAX6225BE_A E 2.5 7.0 MAX6225BMJA M 2.5 8.0 +25C 10 18 VOUT / VIN C 30 E 35 M +25C 10V VIN 36V 2 MIN MAX6225A 8V VIN 10V Line Regulation (Note 2) TA 45 2 C 5 7 E 8 M 10 _______________________________________________________________________________________ V ppm/C ppm/V Low-Noise, Precision, +2.5V/+4.096V/+5V Voltage References (VIN = +10V, IOUT = 0mA, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) PARAMETER SYMBOL CONDITIONS Sourcing: 0mA IOUT 15mA Load Regulation (Note 2) Supply Current VOUT/ IOUT IIN Trim-Adjustment Range Turn-On Settling Time Output Noise Voltage (Note 3) VOUT tON en Temperature Hysteresis Long-Term Stability Sinking: -15mA IOUT 0mA Sinking: -15mA IOUT 0mA VOUT / t TA MIN TYP MAX C 1 6 E 1 7 M 3 15 C 1 6 E 1 7 M 10 30 +25C 1.8 2.7 C, E, M 3.0 25 ppm/mA mA Figure 1 C, E, M To 0.01% of final value +25C 5 s 0.1Hz f 10Hz +25C 1.5 Vp-p 10Hz f 1kHz +25C 1.3 (Note 4) +25C 20 ppm 20 ppm/ 1000hr +25C 15 UNITS mV 2.8 VRMS _______________________________________________________________________________________ 3 MAX6225/MAX6241/MAX6250 ELECTRICAL CHARACTERISTICS--MAX6225 (continued) MAX6225/MAX6241/MAX6250 Low-Noise, Precision, +2.5V/+4.096V/+5V Voltage References ELECTRICAL CHARACTERISTICS--MAX6241 (VIN = +10V, IOUT = 0mA, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) PARAMETER Input Voltage Range Output Voltage Output Voltage Temperature Coefficient (Note 1) SYMBOL CONDITIONS VIN VOUT TCVOUT Turn-On Settling Time Output Noise Voltage (Note 3) 4.097 MAX6241B +25C 4.092 4.096 4.100 MAX6241AC_A C 1.0 2.0 MAX6241AE_A E 1.5 3.0 MAX6241AMJA M 2.0 5.0 MAX6241BC_A C 2.5 5.0 MAX6241BE_A E 2.5 7.0 MAX6241BMJA M 2.5 8.0 +25C 10 Temperature Hysteresis Long-Term Stability 4 VOUT / t 30 E 35 45 +25C 2 C V ppm/C 18 C M IIN en V 4.096 VOUT / IOUT tON 36 8 VOUT / VIN VOUT UNITS 4.095 Sinking: -15mA IOUT 0mA Trim-Adjustment Range MAX +25C Sourcing: 0mA IOUT 15mA Supply Current TYP C, E, M 10V VIN 36V Load Regulation (Note 2) MIN MAX6241A 8V VIN 10V Line Regulation (Note 2) TA 5 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 C, E, M 2.9 3.2 24 40 ppm/mA ppm/mA mA Figure 1 C, E, M To 0.01% of final value +25C 8 s 0.1Hz f 10Hz +25C 2.4 Vp-p 10Hz f 1kHz +25C 2.0 (Note 4) +25C 20 ppm +25C 20 ppm/ 1000hr _______________________________________________________________________________________ mV 4.0 VRMS Low-Noise, Precision, +2.5V/+4.096V/+5V Voltage References (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 TA MIN C, E, M 8 MAX6250A +25C 4.999 5.000 5.001 MAX6250B +25C 4.995 5.000 5.005 C 1.0 2.0 MAX6250AE_A E 1.5 3.0 MAX6250AMJA M 2.0 5.0 MAX6250BC_A C 2.5 5.0 MAX6250BE_A E 2.5 7.0 MAX6250BMJA M 2.5 8.0 +25C 10 18 VIN VOUT MAX6250AC_A Output Voltage Temperature Coefficient (Note 1) TCVOUT 8V VIN 10V Line Regulation (Note 2) VOUT / VIN VOUT / IOUT Sinking: -15mA IOUT 0mA Supply Current IIN Trim-Adjustment Range Turn-On Settling Time Output Noise Voltage (Note 3) VOUT ton en Temperature Hysteresis Long-Term Stability Note 1: Note 2: Note 3: Note 4: VOUT / t UNITS 36 V 30 E 35 45 +25C Sourcing: 0mA IOUT 15mA MAX C M 10V VIN 36V Load Regulation (Note 2) TYP 2 C 5 V 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 +25C 2.0 3.0 C, E, M 3.3 30 50 ppm/mA mA Figure 1 C, E, M To 0.01% of final value +25C 10 mV s 0.1Hz f 10Hz +25C 3.0 Vp-p 10Hz f 1kHz +25C 2.5 (Note 4) +25C 20 ppm +25C 20 ppm/ 1000hr 5.0 VRMS Temperature coefficient is measured by the box method; i.e., the maximum VOUT is divided by T x VOUT. 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. Noise specifications are guaranteed by design. Temperature hysteresis is specified at TA = +25C by measuring VOUT before and after changing temperature by +25C using the PDIP package. _______________________________________________________________________________________ 5 MAX6225/MAX6241/MAX6250 ELECTRICAL CHARACTERISTICS--MAX6250 __________________________________________Typical Operating Characteristics (VIN = +10V, IOUT = 0mA, TA = +25C, unless otherwise noted.) 300 1.5 250 1.0 -0.5 -100 -1.0 -200 125 0 0 -0.5 -1.5 -55 -35 -15 5 25 45 65 5 25 45 240 0.5 200 0.4 160 0.3 120 0.2 80 0.1 40 0 -0.1 -40 -0.2 -80 -0.3 -120 -0.4 -55 -35 -15 -250 85 105 125 65 5 25 -160 85 105 125 65 45 TEMPERATURE (C) TEMPERATURE (C) TEMPERATURE (C) MAX6250 CHANGE IN OUTPUT VOLTAGE vs. OUTPUT CURRENT MAX6241 CHANGE IN OUTPUT VOLTAGE vs. OUTPUT CURRENT MAX6225 CHANGE IN OUTPUT VOLTAGE vs. OUTPUT CURRENT TA = +85C 200 MAX6225 toc06 200 200 MAX6225 toc05 300 MAX6225 toc04 300 280 0.6 0 -125 -1 -55 -35 -15 -300 85 105 125 VOUT (mV) 0.5 VOUT (ppm) VOUT (mV) 0 0 VOUT (ppm) 100 0.5 MAX6225 toc03 0.7 375 200 1.0 VOUT (mV) MAX6225 toc02 1.5 400 150 100 100 TA = +85C TA = -40C -100 0 -100 -200 -150 -300 10 20 30 TA = +85C -250 -40 -30 -20 40 -10 0 10 20 30 -40 -30 -20 40 2.8 2.6 SUPPLY CURRENT (mA) 40 30 20 10 0 MAX6250 2.4 MAX6241 MAX6225 2.2 2.0 1.8 1.6 3.0 2.5 10 15 20 VIN (V) 25 30 35 40 40 MAX6250 2.0 MAX6225 1.0 1.0 5 30 MAX6241 1.2 -20 20 1.5 1.4 -10 3.5 MAX6225 toc08 50 10 SUPPLY CURRENT vs. TEMPERATURE SUPPLY CURRENT vs. SUPPLY VOLTAGE 3.0 MAX6225 toc07 60 0 IOUT (mA) MAX6225 toc09 CHANGE IN OUTPUT VOLTAGE vs. INPUT VOLTAGE 0 -10 IOUT (mA) IOUT (mA) SUPPLY CURRENT (mA) 0 TA = +25C -200 -400 -10 TA = -40C -200 TA = +25C -40 -30 -20 0 -50 -100 TA = -40C -300 6 50 TA = +25C VOUT (V) 0 VOUT (V) VOUT (V) 100 0 5 10 15 20 25 SUPPLY VOLTAGE (V) 30 35 40 -55 -35 -15 5 25 45 65 TEMPERATURE (C) _______________________________________________________________________________________ 85 105 125 VOUT (ppm) MAX6225 toc01 2.0 MAX6225 NORMALIZED OUTPUT VOLTAGE vs. TEMPERATURE MAX6241 NORMALIZED OUTPUT VOLTAGE vs. TEMPERATURE MAX6250 NORMALIZED OUTPUT VOLTAGE vs. TEMPERATURE VOUT (ppm) MAX6225/MAX6241/MAX6250 Low-Noise, Precision, +2.5V/+4.096V/+5V Voltage References Low-Noise, Precision, +2.5V/+4.096V/+5V Voltage References MAX6241 OUTPUT NOISE-VOLTAGE DENSITY vs. FREQUENCY CNR = 0F 35 30 25 20 CNR = 1F 15 10 70 60 50 40 30 10 0 0 100 1k CNR = 1F 20 5 10 CNR = 0F 1k 30 CNR = 1F 20 10 100 MAX6225 toc15 VOUT, 1V/div COUT = CNR = 0F 1sec/div RIPPLE REJECTION vs. FREQUENCY (CNR = 0F) RIPPLE REJECTION vs. FREQUENCY (CNR = 1F) ISINK = 5mA 100 MAX6241 90 MAX6250 80 70 ISOURCE = 5mA 100k 85 MAX6250 80 75 70 65 60 60 1M MAX6225 MAX6241 90 RIPPLE REJECTION (dB) RIPPLE REJECTION (dB) 1 MAX6225 110 95 MAX6225 toc17 120 MAX6225 toc16 10 10k MAX6250 0.1Hz to 10Hz NOISE VOUT, 1V/div VOUT, 0.5V/div 100 1k FREQUENCY (Hz) 1sec/div OUTPUT IMPEDANCE vs. FREQUENCY OUTPUT IMPEDANCE () 40 MAX6225 toc14 1sec/div 1k 10k FREQUENCY (Hz) 50 10k COUT = CNR = 0F COUT = CNR = 0F 100 60 MAX6241 0.1Hz to 10Hz NOISE MAX6225 toc13 10 CNR = 0F 70 FREQUENCY (Hz) MAX6225 0.1Hz to 10Hz NOISE 0.01 80 0 100 FREQUENCY (Hz) 0.1 90 10 10 10k MAX6225 toc12 80 100 MAX6607/08 toc18 40 90 MAX6225 toc11 45 OUTPUT NOISE DENSITY (nV// Hz) MAX6225 toc10 OUTPUT NOISE DENSITY (nV// Hz) 50 MAX6250 OUTPUT NOISE-VOLTAGE DENSITY vs. FREQUENCY OUTPUT NOISE DENSITY (nV// Hz) MAX6225 OUTPUT NOISE-VOLTAGE DENSITY vs. FREQUENCY 10 100 1k FREQUENCY (Hz) 10k 10 100 1k 10k FREQUENCY (Hz) _______________________________________________________________________________________ 7 MAX6225/MAX6241/MAX6250 ____________________________Typical Operating Characteristics (continued) (VIN = 10V, IOUT = 0mA, TA = +25C, unless otherwise noted.) MAX6225/MAX6241/MAX6250 Low-Noise, Precision, +2.5V/+4.096V/+5V Voltage References ____________________________Typical Operating Characteristics (continued) (VIN = 10V, IOUT = 0mA, TA = +25C, unless otherwise noted.) LOAD-TRANSIENT RESPONSE (SINKING) LOAD-TRANSIENT RESPONSE (SOURCING) MAX6225 toc19 MAX6225 toc20 0mA 10mA A A -10mA 0mA B B 2s/div 2s/div A: IOUT, 10mA/div (SOURCING) B: VOUT, 500V/div A: IOUT, 10mA/div (SINKING) B: VOUT, 500V/div MAX6225 TURN-ON AND TURN-OFF TRANSIENT RESPONSE LOAD-TRANSIENT RESPONSE MAX6225 toc22 MAX6225 toc21 -10mA A +10V A +10mA 0 B B VIN = 10V COUT = CNR = 0F CIN = COUT = CNR = 0F 1s/div 1s/div A: VIN, 10V/div B: VOUT, 1V/div A: IOUT (10mA SOURCE AND SINK), 20mA/div, AC COUPLED B: VOUT, 20mV/div, AC COUPLED MAX6241 TURN-ON AND TURN-OFF TRANSIENT RESPONSE MAX6250 TURN-ON AND TURN-OFF TRANSIENT RESPONSE MAX6225 toc24 MAX6225 toc23 +10V A +10V A 0 0 B B CIN = COUT = CNR = 0F CIN = COUT = CNR = 0F 1s/div 1s/div A: VIN, 10V/div B: VOUT, 1V/div 8 A: VIN, 10V/div B: VOUT, 1V/div _______________________________________________________________________________________ Low-Noise, Precision, +2.5V/+4.096V/+5V Voltage References 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 MAX6225/MAX6241/MAX6250 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 MAX6225/MAX6241/MAX6250 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 MAX6250 reference and MAX432 inverting amplifier. The +5V is inverted by the MAX432 chopperstabilized amplifier. 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 MAX6225 MAX6241 MAX6250 * TRIM GND REFERENCE OUT OUT 10k NR 1F MAX6225 MAX6241 MAX6250 TRIM GND *OPTIONAL Figure 1. Output Voltage Adjustment Figure 2. Noise-Reduction Capacitor _______________________________________________________________________________________ 9 MAX6225/MAX6241/MAX6250 _____________________Pin Description MAX6225/MAX6241/MAX6250 Low-Noise, Precision, +2.5V/+4.096V/+5V Voltage References +5V INPUT 3.3F VCC C1+ V+ +REFERENCE OUT IN C1- OUT R2 100k MAX865 3.3F C1 2.2F C2+ C2- GND MAX6250 V- NR TRIM GND C2 1F 2.2F R1 10k C3 2.2F R3 1k C4 1F MAX432 R4 100k -REFERENCE OUT Figure 3. +5V and -5V References from a Single +5V Supply Ordering Information (continued) PART TEMP. RANGE PINPACKAGE MAX TEMPCO (ppm/C) MAX6241ACPA 0C to +70C 8 Plastic DIP 2.0 MAX6241BCPA MAX6241ACSA MAX6241BCSA MAX6241AEPA MAX6241BEPA MAX6241AESA MAX6241BESA MAX6241AMJA MAX6241BMJA MAX6250ACPA MAX6250BCPA MAX6250ACSA MAX6250BCSA MAX6250AEPA MAX6250BEPA MAX6250AESA MAX6250BESA MAX6250AMJA MAX6250BMJA 0C to +70C 0C to +70C 0C to +70C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -55C to +125C -55C to +125C 0C to +70C 0C to +70C 0C to +70C 0C to +70C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -55C to +125C -55C to +125C 8 Plastic DIP 8 SO 8 SO 8 Plastic DIP 8 Plastic DIP 8 SO 8 SO 8 CERDIP 8 CERDIP 8 Plastic DIP 8 Plastic DIP 8 SO 8 SO 8 Plastic DIP 8 Plastic DIP 8 SO 8 SO 8 CERDIP 8 CERDIP 5.0 2.0 5.0 3.0 7.0 3.0 7.0 5.0 8.0 2.0 5.0 2.0 5.0 3.0 7.0 3.0 7.0 5.0 8.0 10 ___________________Chip Information TRANSISTOR COUNT: 435 ______________________________________________________________________________________ Low-Noise, Precision, +2.5V/+4.096V/+5V Voltage References SOICN.EPS PDIPN.EPS ______________________________________________________________________________________ 11 MAX6225/MAX6241/MAX6250 ________________________________________________________Package Information ___________________________________________Package Information (continued) CDIPS.EPS MAX6225/MAX6241/MAX6250 Low-Noise, Precision, +2.5V/+4.096V/+5V Voltage References 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 (c) 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.