19-2647; Rev 2; 6/03 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference Features ♦ Ultra-Low 1.3µVP-P Noise (0.1Hz to 10Hz, 2.048V Output) ♦ Ultra-Low 3ppm/°C (max) Temperature Coefficient ♦ ±0.02% (max) Initial Accuracy ♦ Wide (VOUT + 200mV) to 12.6V Supply Voltage Range ♦ Low 200mV (max) Dropout Voltage ♦ 380µA Quiescent Supply Current ♦ 10mA Sink/Source-Current Capability ♦ Stable with CLOAD = 0.1µF to 10µF ♦ Low 20ppm/1000hr Long-Term Stability ♦ 0.025Ω (max) Load Regulation ♦ 20µV/V (max) Line Regulation ♦ Force and Sense Outputs for Remote Sensing Pin Configuration TOP VIEW NR 1 IN 2 8 I.C.* 7 OUTF 3 6 OUTS GNDS 4 5 I.C.* MAX6126 GND Applications High-Resolution A/D and D/A Converters ATE Equipment SO/µMAX High-Accuracy Reference Standard *I.C. = INTERNALLY CONNECTED. DO NOT USE. Precision Current Sources Digital Voltmeters High-Accuracy Industrial and Process Control Ordering Information PART TEMP RANGE PINPACKAGE OUTPUT VOLTAGE (V) MAXIMUM INITIAL ACCURACY (%) MAXIMUM TEMPCO (-40°C to +85°C) (ppm/°C) TOP MARK — MAX6126AASA21 -40°C to +125°C 8 SO 2.048 0.02 3 MAX6126BASA21 -40°C to +125°C 8 SO 2.048 0.06 5 — MAX6126AAUA21 -40°C to +125°C 8 µMAX 2.048 0.06 3 6126A21 Ordering Information continued at end of data sheet. ________________________________________________________________ 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 MAX6126 General Description The MAX6126 is an ultra-low-noise, high-precision, lowdropout voltage reference. This family of voltage references feature curvature-correction circuitry and high-stability, laser-trimmed, thin-film resistors that result in 3ppm/°C (max) temperature coefficients and an excellent ±0.02% (max) initial accuracy. The proprietary low-noise reference architecture produces a low flicker noise of 1.3µVP-P and wideband noise as low as 60nV/√Hz (2.048V output) without the increased supply current usually found in low-noise references. Improve wideband noise to 35nV/√Hz and AC power-supply rejection by adding a 0.1µF capacitor at the noise reduction pin. The MAX6126 series mode reference operates from a wide 2.7V to 12.6V supply voltage range and load-regulation specifications are guaranteed to be less than 0.025Ω for sink and source currents up to 10mA. These devices are available over the automotive temperature range of -40°C to +125°C. The MAX6126 typically draws 380µA of supply current and is available in 2.048V, 2.500V, 3.000V, 4.096V, and 5.000V output voltages. These devices also feature dropout voltages as low as 200mV. Unlike conventional shunt-mode (two-terminal) references that waste supply current and require an external resistor, the MAX6126 offers supply current that is virtually independent of supply voltage and does not require an external resistor. The MAX6126 is stable with 0.1µF to 10µF of load capacitance. The MAX6126 is available in the tiny 8-pin µMAX, as well as 8-pin SO packages. MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND) GNDS ....................................................................-0.3V to +0.3V IN ........................................................................... -0.3V to +13V OUTF, OUTS, NR........ -0.3V to the lesser of (VIN + 0.3V) or +6V Output Short Circuit to GND or IN ..........................................60s Continuous Power Dissipation (TA = +70°C) 8-Pin µMAX (derate 4.5mW/°C above +70°C) ............362mW 8-Pin SO (derate 5.88mW/°C above +70°C) ...............471mW Operating Temperature Range ........................-40°C to +125°C Junction Temperature .....................................................+150°C Storage Temperature Range ............................-65°C to +150°C Lead Temperature (soldering, 10s) ................................+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—MAX6126_21 (VOUT = 2.048V) (VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX A grade SO -0.02 +0.02 B grade SO -0.06 +0.06 A grade µMAX -0.06 +0.06 B grade µMAX -0.1 +0.1 UNITS OUTPUT Output Voltage VOUT TA = +25°C Referred to VOUT, TA = +25°C Output Voltage Accuracy TA = -40°C to +85°C Output Voltage Temperature Coefficient (Note 1) TCVOUT TA = -40°C to +125°C V A grade SO 0.5 3 B grade SO 1 5 A grade µMAX 1 3 B grade µMAX 2 7 A grade SO 1 5 B grade SO 2 10 A grade µMAX 2 5 B grade µMAX 3 12 TA = +25°C 2 Line Regulation ∆VOUT/ ∆VIN 2.7V ≤ VIN ≤ 12.6V Load Regulation ∆VOUT/ ∆IOUT Sourcing: 0 ≤ IOUT ≤ 10mA 0.7 25 Sinking: -10mA ≤ IOUT ≤ 0 1.3 25 Short to GND 160 Short to IN 20 SO 25 µMAX 80 OUT Short-Circuit Current 2 2.048 ISC Thermal Hysteresis (Note 2) ∆VOUT/ cycle Long-Term Stability ∆VOUT/ time TA = -40°C to +125°C 1000hr at TA = +25°C 20 40 SO 20 µMAX 100 _______________________________________________________________________________________ % ppm/°C µV/V µV/mA mA ppm ppm/ 1000hr Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference (VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DYNAMIC CHARACTERISTICS Noise Voltage eOUT Turn-On Settling Time Capacitive-Load Stability Range tR CLOAD f = 0.1Hz to 10Hz 1.3 f = 1kHz, CNR = 0 60 f = 1kHz, CNR = 0.1µF 35 To VOUT = 0.01% of final value CNR = 0 0.8 CNR = 0.1µF 20 No sustained oscillations µVP-P nV/√Hz ms 0.1 to 10 µF INPUT Supply Voltage Range Quiescent Supply Current VIN IIN Guaranteed by line-regulation test 2.7 TA = +25°C 12.6 380 TA = -40°C to +125°C 550 725 V µA ELECTRICAL CHARACTERISTICS—MAX6126_25 (VOUT = 2.500V) (VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS OUTPUT Output Voltage VOUT TA = +25°C Referred to VOUT, TA = +25°C Output Voltage Accuracy TA = -40°C to +85°C Output Voltage Temperature Coefficient (Note 1) TCVOUT TA = -40°C to +125°C Line Regulation ∆VOUT/ ∆VIN Load Regulation ∆VOUT/ ∆IOUT 2.7V ≤ VIN ≤ 12.6V 2.500 V A grade SO -0.02 +0.02 B grade SO -0.06 +0.06 A grade µMAX -0.06 +0.06 B grade µMAX -0.1 +0.1 A grade SO 0.5 3 B grade SO 1 5 A grade µMAX 1 3 B grade µMAX 2 7 A grade SO 1 5 B grade SO 2 10 A grade µMAX 2 5 B grade µMAX 3 12 TA = +25°C 3 20 TA = -40°C to +125°C 40 Sourcing: 0 ≤ IOUT ≤ 10mA 1 25 Sinking: -10mA ≤ IOUT ≤ 0 1.8 25 % ppm/°C µV/V µV/mA _______________________________________________________________________________________ 3 MAX6126 ELECTRICAL CHARACTERISTICS—MAX6126_21 (VOUT = 2.048V) (continued) MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference ELECTRICAL CHARACTERISTICS—MAX6126_25 (VOUT = 2.500V) (continued) (VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER Dropout Voltage (Note 3) OUT Short-Circuit Current SYMBOL CONDITIONS VIN - VOUT ∆VOUT = 0.1% ISC Thermal Hysteresis (Note 2) ∆VOUT/ cycle Long-Term Stability ∆VOUT/ time TYP MAX IOUT = 5mA MIN 0.06 0.2 IOUT = 10mA 0.12 0.4 Short to GND 160 Short to IN 20 SO 35 µMAX 80 UNITS V mA ppm SO 20 µMAX 100 ppm/ 1000hr f = 0.1Hz to 10Hz 1.45 µVP-P f = 1kHz, CNR = 0 75 f = 1kHz, CNR = 0.1µF 45 1000hr at TA = +25°C DYNAMIC CHARACTERISTICS Noise Voltage Turn-On Settling Time Capacitive-Load Stability Range eOUT tR CLOAD To VOUT = 0.01% of final value CNR = 0 1 CNR = 0.1µF 20 No sustained oscillations nV/√Hz ms 0.1 to 10 µF INPUT Supply Voltage Range Quiescent Supply Current VIN IIN Guaranteed by line-regulation test 2.7 TA = +25°C 12.6 380 TA = -40°C to +125°C 550 725 V µA ELECTRICAL CHARACTERISTICS—MAX6126_30 (VOUT = 3.000V) (VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS OUTPUT Output Voltage VOUT TA = +25°C Referred to VOUT, TA = +25°C Output Voltage Accuracy TA = -40°C to +85°C Output Voltage Temperature Coefficient (Note 1) TCVOUT TA = -40°C to +125°C 4 3.000 V A grade SO -0.02 +0.02 B grade SO -0.06 +0.06 A grade µMAX -0.06 +0.06 B grade µMAX -0.1 +0.1 A grade SO 0.5 3 B grade SO 1 5 A grade µMAX 1 3 B grade µMAX 2 7 A grade SO 1 5 B grade SO 2 10 A grade µMAX 2 5 B grade µMAX 3 12 _______________________________________________________________________________________ % ppm/°C Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference MAX6126 ELECTRICAL CHARACTERISTICS—MAX6126_30 (VOUT = 3.000V) (continued) (VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL Line Regulation ∆VOUT/ ∆VIN Load Regulation ∆VOUT/ ∆IOUT Dropout Voltage (Note 3) OUT Short-Circuit Current CONDITIONS 3.2V ≤ VIN ≤ 12.6V Thermal Hysteresis (Note 2) ∆VOUT/ cycle Long-Term Stability ∆VOUT/ time TYP MAX 4 25 TA = -40°C to +125°C 50 Sourcing: 0 ≤ IOUT ≤ 10mA 1.5 30 Sinking: -10mA ≤ IOUT ≤ 0 2.8 30 VIN - VOUT ∆VOUT = 0.1% ISC MIN TA = +25°C IOUT = 5mA 0.06 0.2 IOUT = 10mA 0.11 0.4 Short to GND 160 Short to IN 20 SO 20 µMAX 80 UNITS µV/V µV/mA V mA ppm SO 20 µMAX 100 ppm/ 1000hr f = 0.1Hz to 10Hz 1.75 µVP-P f = 1kHz, CNR = 0 90 f = 1kHz, CNR = 0.1µF 55 1000hr at TA = +25°C DYNAMIC CHARACTERISTICS Noise Voltage eOUT Capacitive-Load Stability Range Turn-On Settling Time CLOAD tR No sustained oscillations To VOUT = 0.01% of final value nV/√Hz 0.1 to 10 CNR = 0 1.2 CNR = 0.1µF 20 µF ms INPUT Supply Voltage Range VIN Quiescent Supply Current IIN Guaranteed by line-regulation test 3.2 TA = +25°C 12.6 380 TA = -40°C to +125°C 550 725 V µA ELECTRICAL CHARACTERISTICS—MAX6126_41 (VOUT = 4.096V) (VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS OUTPUT Output Voltage VOUT Output Voltage Accuracy TA = +25°C Referred to VOUT, TA = +25°C 4.096 V A grade SO -0.02 +0.02 B grade SO -0.06 +0.06 A grade µMAX -0.06 +0.06 B grade µMAX -0.1 +0.1 % _______________________________________________________________________________________ 5 MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference ELECTRICAL CHARACTERISTICS—MAX6126_41 (VOUT = 4.096V) (continued) (VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS TA = -40°C to +85°C Output Voltage Temperature Coefficient (Note 1) TCVOUT TA = -40°C to +125°C Line Regulation ∆VOUT/ ∆VIN Load Regulation ∆VOUT/ ∆IOUT Dropout Voltage (Note 3) OUT Short-Circuit Current 4.3V ≤ VIN ≤ 12.6V Thermal Hysteresis (Note 2) ∆VOUT/ cycle Long-Term Stability ∆VOUT/ time TYP MAX A grade SO 0.5 3 B grade SO 1 5 A grade µMAX 1 3 B grade µMAX 2 7 A grade SO 1 5 B grade SO 2 10 A grade µMAX 2 5 B grade µMAX 3 12 4.5 30 TA = +25°C TA = -40°C to +125°C 60 Sourcing: 0 ≤ IOUT ≤ 10mA 2 40 Sinking: -10mA ≤ IOUT ≤ 0 5 40 VIN - VOUT ∆VOUT = 0.1% ISC MIN IOUT = 5mA 0.05 0.2 IOUT = 10mA 0.1 0.4 Short to GND 160 Short to IN 20 SO 20 µMAX 80 UNITS ppm/°C µV/V µV/mA V mA ppm SO 20 µMAX 100 ppm/ 1000hr f = 0.1Hz to 10Hz 2.4 µVP-P f = 1kHz, CNR = 0 120 f = 1kHz, CNR = 0.1µF 80 1000hr at TA = +25°C DYNAMIC CHARACTERISTICS Noise Voltage Capacitive-Load Stability Range Turn-On Settling Time eOUT CLOAD tR No sustained oscillations To VOUT = 0.01% of final value nV/√Hz 0.1 to 10 CNR = 0 1.6 CNR = 0.1µF 20 µF ms INPUT Supply Voltage Range Quiescent Supply Current 6 VIN IIN Guaranteed by line-regulation test TA = +25°C 4.3 12.6 380 TA = -40°C to +125°C _______________________________________________________________________________________ 550 725 V µA Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference MAX6126 ELECTRICAL CHARACTERISTICS—MAX6126_50 (VOUT = 5.000V) (VIN = 5.5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS OUTPUT Output Voltage VOUT Output Voltage Accuracy TA = +25°C TA = +25°C TA = -40°C to +85°C Output Voltage Temperature Coefficient (Note 1) TCVOUT TA = -40°C to +125°C Line Regulation ∆VOUT/ ∆VIN Load Regulation ∆VOUT/ ∆IOUT Dropout Voltage (Note 3) OUT Short-Circuit Current 5.2V ≤ VIN ≤ 12.6V Thermal Hysteresis (Note 2) ∆VOUT/ cycle Long-Term Stability ∆VOUT/ time V A grade SO -0.02 +0.02 B grade SO -0.06 +0.06 A grade µMAX -0.06 +0.06 B grade µMAX -0.1 % +0.1 A grade SO 0.5 3 B grade SO 1 5 A grade µMAX 1 3 B grade µMAX 2 7 A grade SO 1 5 B grade SO 2 10 A grade µMAX 2 5 B grade µMAX 3 12 TA = +25°C 3 40 TA = -40°C to +125°C 80 Sourcing: 0 ≤ IOUT ≤ 10mA 2.5 50 Sinking: -10mA ≤ IOUT ≤ 0 6.5 50 VIN - VOUT ∆VOUT = 0.1% ISC 5.000 IOUT = 5mA 0.05 0.2 IOUT = 10mA 0.1 0.4 Short to GND 160 Short to IN 20 SO 15 µMAX 80 ppm/°C µV/V µV/mA V mA ppm SO 20 µMAX 100 ppm/ 1000hr f = 0.1Hz to 10Hz 2.85 µVP-P f = 1kHz, CNR = 0 145 f = 1kHz, CNR = 0.1µF 95 1000hr at TA = +25°C DYNAMIC CHARACTERISTICS Noise Voltage eOUT Capacitive-Load Stability Range CLOAD No sustained oscillations 0.1 to 10 nV/√Hz µF _______________________________________________________________________________________ 7 ELECTRICAL CHARACTERISTICS—MAX6126_50 (VOUT = 5.000V) (continued) (VIN = 5.5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL Turn-On Settling Time CONDITIONS To VOUT = 0.01% of final value tR MIN TYP CNR = 0 2 CNR = 0.1µF 20 MAX UNITS ms INPUT Supply Voltage Range VIN Quiescent Supply Current Guaranteed by line-regulation test 5.2 12.6 TA = +25°C IIN 380 V 550 TA = -40°C to +125°C µA 725 Note 1: Temperature coefficient is measured by the “box” method, i.e., the maximum ∆VOUT / VOUT is divided by the maximum ∆T. Note 2: Thermal hysteresis is defined as the change in +25°C output voltage before and after cycling the device from TMAX to TMIN. Note 3: Dropout voltage is defined as the minimum differential voltage (VIN - VOUT) at which VOUT decreases by 0.1% from its original value at VIN = 5.0V (VIN = 5.5V for VOUT = 5.0V). Typical Operating Characteristics (VIN = 5V for MAX6126_21/25/30/41, VIN = 5.5V for MAX6126_50, CLOAD = 0.1µF, IOUT = 0, TA = +25°C, unless otherwise specified.) (Note 5) OUTPUT VOLTAGE (V) 2.0485 2.0480 2.0475 2.0470 THREE TYPICAL PARTS 5.002 2.0485 OUTPUT VOLTAGE (V) THREE TYPICAL PARTS MAX6126 toc02 2.0490 MAX6126 toc01 2.0490 MAX6126A_50 OUTPUT VOLTAGE TEMPERATURE DRIFT (VOUT = 5.000V) (SO) 2.0480 2.0475 MAX6126 toc03 MAX6126A_21 OUTPUT VOLTAGE TEMPERATURE DRIFT (VOUT = 2.048V) (µMAX) MAX6126A_21 OUTPUT VOLTAGE TEMPERATURE DRIFT (VOUT = 2.048V) (SO) OUTPUT VOLTAGE (V) MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference THREE TYPICAL PARTS 5.001 5.000 4.999 2.0465 2.0460 2.0470 -50 -25 0 25 50 75 TEMPERATURE (°C) 8 100 125 4.998 -50 -25 0 25 50 75 TEMPERATURE (°C) 100 125 -50 -25 0 25 50 75 TEMPERATURE (°C) _______________________________________________________________________________________ 100 125 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference 5.000 4.999 MAX6126 toc05 5.001 TA = +25°C 2.0480 TA = +25°C 5.000 OUTPUT VOLTAGE (V) 5.001 MAX6126_50 LOAD REGULATION 2.0485 MAX6126 toc04 THREE TYPICAL PARTS OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 5.002 MAX6126_21 LOAD REGULATION 2.0475 TA = -40°C 2.0470 MAX6126 toc06 MAX6126A_50 OUTPUT VOLTAGE TEMPERATURE DRIFT (VOUT = 5.000V) (µMAX) 2.0465 4.999 TA = -40°C 4.998 TA = +125°C 4.997 TA = +125°C 2.0460 4.998 0 25 50 75 -10 0 10 5 MAX6126_50 DROPOUT VOLTAGE vs. SOURCE CURRENT MAX6126_21 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY TA = +25°C 100 TA = -40°C 200 -20 -40 150 TA = +125°C 100 TA = +25°C TA = -40°C -100 0 3 6 9 12 15 0 -60 -80 50 0 0 MAX6126 toc09 250 MAX6126 toc07 TA = +125°C 0 -5 MAX6126_25 DROPOUT VOLTAGE vs. SOURCE CURRENT DROPOUT VOLTAGE (mV) 3 6 9 -120 0.001 15 12 0.01 0.1 1 10 100 1000 SOURCE CURRENT (mA) SOURCE CURRENT (mA) FREQUENCY (kHz) MAX6126_50 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY MAX6126_21 SUPPLY CURRENT vs. INPUT VOLTAGE MAX6126_50 SUPPLY CURRENT vs. INPUT VOLTAGE -40 -60 -80 500 TA = +125°C 400 TA = +25°C TA = -40°C 300 200 700 600 TA = +125°C 500 TA = +25°C 400 TA = -40°C 300 200 100 -100 800 SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) -20 900 MAX6126 toc12 600 MAX6126 toc10 0 MAX6126 toc11 DROPOUT VOLTAGE (mV) 10 5 OUTPUT CURRENT (mA) 50 PSRR (dB) 0 OUTPUT CURRENT (mA) 250 150 -5 TEMPERATURE (°C) 300 200 4.996 -10 125 100 PSRR (dB) -25 MAX6126 toc08 -50 100 -120 0.001 0 0.01 0.1 1 10 FREQUENCY (kHz) 100 1000 0 0 2 4 6 8 10 INPUT VOLTAGE (V) 12 14 0 2 4 6 8 10 12 14 INPUT VOLTAGE (V) _______________________________________________________________________________________ 9 MAX6126 Typical Operating Characteristics (continued) (VIN = 5V for MAX6126_21/25/30/41, VIN = 5.5V for MAX6126_50, CLOAD = 0.1µF, IOUT = 0, TA = +25°C, unless otherwise specified.) (Note 5) MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference Typical Operating Characteristics (continued) (VIN = 5V for MAX6126_21/25/30/41, VIN = 5.5V for MAX6126_50, CLOAD = 0.1µF, IOUT = 0, TA = +25°C, unless otherwise specified.) (Note 5) MAX6126_21 OUTPUT NOISE (0.1Hz TO 10Hz) MAX6126_50 OUTPUT NOISE (0.1Hz TO 10Hz) MAX6126 toc13 MAX6126 toc14 VOUT = 2.048V VOUT = 5V 0.4µV/div 1µV/div 1s/div 1s/div MAX6126_21 LOAD TRANSIENT MAX6126_21 LOAD TRANSIENT MAX6126 toc16 MAX6126 toc15 10mA 1mA IOUT 5mA/div IOUT 500µA/div 0mA -100µA VOUT AC-COUPLED 100mV/div VOUT AC-COUPLED 20mV/div 200µs/div 200µs/div CLOAD = 0.1µF VIN = 5V CLOAD = 0.1µF VIN = 5V IOUT = 0 TO 10mA VOUT = 2.048V IOUT = -100µA TO 1mA VOUT = 2.048V MAX6126_21 LOAD TRANSIENT MAX6126_21 LOAD TRANSIENT MAX6126 toc18 MAX6126 toc17 10mA -1mA IOUT 5mA/div IOUT 5mA/div 0mA -10mA VOUT AC-COUPLED 20mV/div VOUT AC-COUPLED 100mV/div 1ms/div 400µs/div CLOAD = 0.1µF VIN = 5V 10 IOUT = -1mA TO -10mA VOUT = 2.048V CLOAD = 10µF VIN = 5V IOUT = 0 TO 10mA VOUT = 2.048V ______________________________________________________________________________________ Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference MAX6126_21 LOAD TRANSIENT MAX6126_21 LOAD TRANSIENT MAX6126 toc19 MAX6126 toc20 +1mA IOUT 500µA/div -1mA IOUT 5mA/div -100µA -10mA VOUT AC-COUPLED 10mV/div VOUT AC-COUPLED 50mV/div 1ms/div CLOAD = 10µF VIN = 5V 400µs/div CLOAD = 10µF VIN = 5V IOUT = -100µA TO 1mA VOUT = 2.048V IOUT = -1mA TO -10mA VOUT = 2.048V MAX6126_50 LINE TRANSIENT MAX6126_21 LINE TRANSIENT MAX6126 toc22 MAX6126 toc21 3.2V 5.7V VIN 200mV/div VIN 200mV/div 2.7V 5.2V VOUT AC-COUPLED 20mV/div VOUT AC-COUPLED 10mV/div 400µs/div 20µs/div VOUT = 2.048V VIN = 5.2V TO 5.7V VOUT = 5V CLOAD = 0.1µF CLOAD = 0.1µF MAX6126_50 TURN-ON TRANSIENT MAX6126_21 TURN-ON TRANSIENT MAX6126 toc24 MAX6126 toc23 5.5V 5.5V VIN 2V/div VIN 2V/div GND GND VOUT 1V/div VOUT 2V/div GND 200µs/div 20µs/div CLOAD = 0.1µF VOUT = 2.048V CLOAD = 0.1µF VOUT = 5V ______________________________________________________________________________________ 11 MAX6126 Typical Operating Characteristics (continued) (VIN = 5V for MAX6126_21/25/30/41, VIN = 5.5V for MAX6126_50, CLOAD = 0.1µF, IOUT = 0, TA = +25°C, unless otherwise specified.) (Note 5) Typical Operating Characteristics (continued) (VIN = 5V for MAX6126_21/25/30/41, VIN = 5.5V for MAX6126_50, CLOAD = 0.1µF, IOUT = 0, TA = +25°C, unless otherwise specified.) (Note 5) MAX6126 toc25 MAX6126 toc26 2.5006 5.5V 2.5004 VIN 2V/div VIN 2V/div 2.5002 GND GND VOUT (V) 5.5V TWO TYPICAL PARTS VOUT = 2.5V 2.5000 2.4998 VOUT 2V/div VOUT 1V/div MAX6126 toc27 MAX6126B_25 LONG-TERM STABILITY vs. TIME (SO) MAX6126_50 TURN-ON TRANSIENT MAX6126_21 TURN-ON TRANSIENT 2.4996 GND 2.4994 0 400µs/div 200 400 CLOAD = 10µF VOUT = 5V CLOAD = 10µF VOUT = 2.048V MAX6126B_25 LONG-TERM STABILITY vs. TIME (µMAX) TWO TYPICAL PARTS VOUT = 5V 5.0004 1000 5.0010 MAX6126 toc29 5.0006 800 MAX6126B_50 LONG-TERM STABILITY vs. TIME (µMAX) MAX6126B_50 LONG-TERM STABILITY vs. TIME (SO) MAX6126 toc28 2.5010 600 TIME (hr) MAX6126 toc30 40µs/div TWO TYPICAL PARTS VOUT = 5V 5.0005 2.5005 2.5000 VOUT (V) VOUT (V) 5.0002 VOUT (V) MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference 5.0000 5.0000 4.9998 4.9995 2.4995 4.9996 TWO TYPICAL PARTS VOUT = 2.5V 2.4990 4.9990 4.9994 0 200 400 600 TIME (hr) 800 1000 0 200 400 600 800 1000 0 200 400 TIME (hr) 600 800 TIME (hr) Note 5: Many of the MAX6126 Typical Operating Characteristics are extremely similar. The extremes of these characteristics are found in the MAX6126_21 (2.048V output) and the MAX6126_50 (5.000V output). The Typical Operating Characteristics of the remainder of the MAX6126 family typically lie between those two extremes and can be estimated based on their output voltages. 12 ______________________________________________________________________________________ 1000 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference MAX6126 Pin Description (VOUT + 200mV) TO 12.6V INPUT PIN NAME FUNCTION 1 NR Noise Reduction. Connect a 0.1µF capacitor to improve wideband noise. Leave unconnected if not used (see Figure 1). 2 IN Positive Power-Supply Input 3 GND 4 GNDS Ground-Sense Connection. Connect to ground connection at load. 5, 8 I.C. Internally Connected. Do not connect anything to these pins. 6 OUTS Voltage Reference Sense Output OUTF Voltage Reference Force Output. Short OUTF to OUTS as close to the load as possible. Bypass OUTF with a capacitor (0.1µF to 10µF) to GND. 7 IN OUTF MAX6126 REFERENCE OUTPUT OUTS * Ground NR 0.1µF* GND GNDS *OPTIONAL. Figure 1. Noise-Reduction Capacitor Detailed Description Wideband Noise Reduction To improve wideband noise and transient power-supply noise, add a 0.1µF capacitor to NR (Figure 1). Larger values do not improve noise appreciably. A 0.1µF NR capacitor reduces the noise from 60nV/√Hz to 35nV/√Hz for the 2.048V output. Noise in the powersupply input can affect output noise, but can be reduced by adding an optional bypass capacitor between IN and GND, as shown in the Typical Operating Circuit. Output Bypassing The MAX6126 requires an output capacitor between 0.1µF and 10µF. Locate the output capacitor as close to OUTF as possible. For applications driving switching capacitive loads or rapidly changing load currents, it is advantageous to use a 10µF capacitor in parallel with a 0.1µF capacitor. Larger capacitor values reduce transients on the reference output. Supply Current The quiescent supply current of the series-mode MAX6126 family is typically 380µA and is virtually independent of the supply voltage, with only a 2µA/V (max) variation with supply voltage. When the supply voltage is below the minimum specified input voltage during turn-on, the device can draw up to 300µA beyond the nominal supply current. The input voltage source must be capable of providing this current to ensure reliable turn-on. Thermal Hysteresis Thermal hysteresis is the change of output voltage at TA = +25°C before and after the device is cycled over its entire operating temperature range. The typical thermal hysteresis value is 20ppm (SO package). Turn-On Time These devices typically turn on and settle to within 0.1% of their final value in 200µs to 2ms depending on the device. The turn-on time can increase up to 4ms with the device operating at the minimum dropout voltage and the maximum load. A noise reduction capacitor of 0.1µF increases the turn-on time to 20ms. Output Force and Sense The MAX6126 provides independent connections for the power-circuit output (OUTF) supplying current into a load, and for the circuit input regulating the voltage applied to that load (OUTS). This configuration allows for the cancellation of the voltage drop on the lines connecting the MAX6126 and the load. When using the Kelvin connection made possible by the independent current and voltage connections, take the power connection to the load from OUTF, and bring a line from OUTS to join the line from OUTF, at the point where the voltage accu- ______________________________________________________________________________________ 13 MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference racy is needed. The MAX6126 has the same type of Kelvin connection to cancel drops in the ground return line. Connect the load to ground and bring a connection from GNDS to exactly the same point. IN ISOURCE Applications Information Precision Current Source Figure 2 shows a typical circuit providing a precision current source. The OUTF output provides the bias current for the bipolar transistor. OUTS and GNDS sense the voltage across the resistor and adjust the current sourced by OUTF accordingly. For even higher precision, use a MOSFET to eliminate base current errors. MAX6126 OUTF OUTS GND R GNDS High-Resolution DAC and Reference from a Single Supply Figure 3 shows a typical circuit providing the reference for a high-resolution, 16-bit MAX541 D/A converter. Temperature Coefficient vs. Operating Temperature Range for a 1 LSB Maximum Error In a data converter application, the reference voltage of the converter must stay within a certain limit to keep the error in the data converter smaller than the resolution limit through the operating temperature range. Figure 4 shows the maximum allowable reference voltage temperature coefficient to keep the conversion error to less than 1 LSB, as a function of the operating temperature range (TMAX - TMIN) with the converter resolution as a parameter. The graph assumes the reference voltage temperature coefficient as the only parameter affecting accuracy. In reality, the absolute static accuracy of a data converter is dependent on the combination of many parameters such as integral nonlinearity, differential nonlinearity, offset error, gain error, as well as voltage reference changes. VOUT(NOMINAL) / R = ISOURCE Figure 2. Precision Current Source 3V SUPPLY VDD IN MAX6126 OUTF REF MAX541 DAC OUT ANALOG OUTPUT OUTS GND GNDS GND Figure 3. 14-Bit High-Resolution DAC and Positive Reference from a Single 3V Supply 14 ______________________________________________________________________________________ Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference MAX6126 10,000 1000 100 TEMPERATURE COEFFICIENT (ppm/°C) 8 BIT 10 10 BIT 12 BIT 1 14 BIT 16 BIT 0.1 18 BIT 0.01 1 20 BIT 100 10 OPERATING TEMPERATURE RANGE (TMAX - TMIN) (°C) Figure 4. Temperature Coefficient vs. Operating Temperature Range for a 1 LSB Maximum Error Typical Operating Circuit Chip Information TRANSISTOR COUNT: 1171 PROCESS: BiCMOS (VOUT + 200mV) TO 12.6V INPUT IN OUTF MAX6126 REFERENCE OUTPUT OUTS * NR LOAD * GND GNDS *OPTIONAL. ______________________________________________________________________________________ 15 MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference Ordering Information (continued) PART TEMP RANGE PINPACKAGE OUTPUT VOLTAGE (V) MAXIMUM INITIAL ACCURACY (%) MAXIMUM TEMPCO (-40°C to +85°C) (ppm/°C) TOP MARK MAX6126BAUA21 -40°C to +125°C 8 µMAX 2.048 0.1 7 6126B21 MAX6126AASA25 -40°C to +125°C 8 SO 2.500 0.02 3 — MAX6126BASA25 -40°C to +125°C 8 SO 2.500 0.06 5 — MAX6126AAUA25 -40°C to +125°C 8 µMAX 2.500 0.06 3 6126A25 MAX6126BAUA25 -40°C to +125°C 8 µMAX 2.500 0.1 7 6126B25 MAX6126AASA30 -40°C to +125°C 8 SO 3.000 0.02 3 — MAX6126BASA30 -40°C to +125°C 8 SO 3.000 0.06 5 — MAX6126AAUA30 -40°C to +125°C 8 µMAX 3.000 0.06 3 6126A30 MAX6126BAUA30 -40°C to +125°C 8 µMAX 3.000 0.1 7 6126B30 MAX6126AASA41 -40°C to +125°C 8 SO 4.096 0.02 3 — MAX6126BASA41 -40°C to +125°C 8 SO 4.096 0.06 5 — MAX6126AAUA41 -40°C to +125°C 8 µMAX 4.096 0.06 3 6126A41 MAX6126BAUA41 -40°C to +125°C 8 µMAX 4.096 0.1 7 6126B41 MAX6126AASA50 -40°C to +125°C 8 SO 5.000 0.02 3 — MAX6126BASA50 -40°C to +125°C 8 SO 5.000 0.06 5 — MAX6126AAUA50 -40°C to +125°C 8 µMAX 5.000 0.06 3 6126A50 MAX6126BAUA50 -40°C to +125°C 8 µMAX 5.000 0.1 7 6126B50 16 ______________________________________________________________________________________ Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference N E H INCHES MILLIMETERS MAX MIN 0.069 0.053 0.010 0.004 0.014 0.019 0.007 0.010 0.050 BSC 0.150 0.157 0.228 0.244 0.016 0.050 MAX MIN 1.35 1.75 0.10 0.25 0.35 0.49 0.19 0.25 1.27 BSC 3.80 4.00 5.80 6.20 0.40 SOICN .EPS DIM A A1 B C e E H L 1.27 VARIATIONS: 1 INCHES TOP VIEW DIM D D D MIN 0.189 0.337 0.386 MAX 0.197 0.344 0.394 MILLIMETERS MIN 4.80 8.55 9.80 MAX 5.00 8.75 10.00 N MS012 8 AA 14 AB 16 AC D A B e C 0∞-8∞ A1 L FRONT VIEW SIDE VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, .150" SOIC APPROVAL DOCUMENT CONTROL NO. 21-0041 REV. B 1 1 ______________________________________________________________________________________ 17 MAX6126 Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages. Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages. 4X S 8 8 INCHES DIM A A1 A2 b E ÿ 0.50±0.1 H c D e E H 0.6±0.1 L 1 1 α 0.6±0.1 S BOTTOM VIEW D MIN 0.002 0.030 MAX 0.043 0.006 0.037 0.010 0.014 0.005 0.007 0.116 0.120 0.0256 BSC 0.116 0.120 0.188 0.198 0.016 0.026 0∞ 6∞ 0.0207 BSC 8LUMAXD.EPS MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference MILLIMETERS MAX MIN 0.05 0.75 1.10 0.15 0.95 0.25 0.36 0.13 0.18 2.95 3.05 0.65 BSC 2.95 3.05 4.78 5.03 0.41 0.66 0∞ 6∞ 0.5250 BSC TOP VIEW A1 A2 A α c e b L SIDE VIEW FRONT VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, 8L uMAX/uSOP APPROVAL DOCUMENT CONTROL NO. 21-0036 REV. J 1 1 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. 18 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.