19-2507; Rev 0; 7/02 Ultra-Low-Power Series Voltage Reference Features ♦ Ultra-Low 5.25µA (max) Supply Current ♦ 4mA Output Source Current ♦ 1mA Output Sink Current ♦ ±0.4% (max) Initial Accuracy ♦ 40ppm/°C (max) Temperature Coefficient ♦ 2.5V to 12.6V Supply Range ♦ Low 200mV Dropout ♦ Stable with Capacitive Loads Up to 10µF ♦ No External Capacitors Required ♦ Miniature 5-Pin SOT23 Package Ordering Information PART TEMP RANGE OUTPUT PINVOLTAGE PACKAGE (V) MAX6129_EUK21-T -40°C to +85°C 5 SOT23-5 2.048 MAX6129_EUK25-T -40°C to +85°C 5 SOT23-5 2.500 Battery-Powered Systems MAX6129_EUK30-T -40°C to +85°C 5 SOT23-5 3.000 Hand-Held Instruments MAX6129_EUK33-T -40°C to +85°C 5 SOT23-5 3.300 Precision Power Supplies MAX6129_EUK41-T -40°C to +85°C 5 SOT23-5 4.096 A/D and D/A Converters MAX6129_EUK50-T -40°C to +85°C 5 SOT23-5 5.000 Applications Note: The MAX6129 is available in A or B grades. Choose the desired grade from the Selector Guide and insert the suffix in the blank above to complete the part number. Selector Guide appears at end of data sheet. Pin Configuration Typical Operating Circuit VIN = 2.5V TO 12.6V TOP VIEW * IN 1 5 OUT 4 N.C. IN GND 2 MAX6129 MAX6129 OUT N.C. 3 GND SOT23 *CAPACITOR IS OPTIONAL ________________________________________________________________ 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 MAX6129 General Description The MAX6129 micropower, low-dropout bandgap voltage reference combines ultra-low supply current and low drift in a miniature 5-pin SOT23 surface-mount package that uses 70% less board space than comparable devices in an SO package. This series-mode voltage reference sources up to 4mA and sinks up to 1mA of load current. A wide 2.5V to 12.6V supply range, ultra-low 5.25µA (max) supply current, and a low 200mV dropout voltage make these devices ideal for battery-operated systems. An initial accuracy of 0.4% and a 40ppm/°C (max) temperature coefficient make the MAX6129 suitable for precision applications. Additionally, an internal compensation capacitor eliminates the need for an external compensation capacitor and ensures stability with load capacitances up to 10µF. The MAX6129 provides six output voltages of 2.048V, 2.5V, 3V, 3.3V, 4.096V, and 5V. The MAX6129 is available in a 5-pin SOT23 package and is specified over the extended temperature range (-40°C to +85°C). MAX6129 Ultra-Low-Power Series Voltage Reference ABSOLUTE MAXIMUM RATINGS IN to GND ...............................................................-0.3V to +13V OUT to GND ..............-0.3V to the lower of +6V and (VIN + 0.3V) Output to GND Short-Circuit Duration........................Continuous Continuous Power Dissipation (TA = +70°C) 5-Pin SOT23 (derate 7.1mW/°C above +70°C)............571mW Operating Temperature Range ...........................-40°C to +85°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—MAX6129_21 (VOUT = 2.048V) (VIN = 2.5V, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS OUTPUT Output Voltage Output Voltage Temperature Coefficient (Notes 2, 3) Line Regulation Load Regulation Output Short-Circuit Current VOUT TCVOUT TA = +25°C MAX6129A (±0.4%) 2.0398 2.0480 2.0562 MAX6129B (±1%) 2.0275 2.0480 2.0685 MAX6129A 40 MAX6129B 100 ∆VOUT/∆VIN VIN = 2.5V to 12.6V ∆VOUT/ ∆IOUT 27 200 IOUT = 0 to 4mA 0.22 0.7 IOUT = 0 to -1mA 2.4 5.5 ISC V ppm/°C µV/V µV/µA 60 mA Long-Term Stability ∆VOUT/time 1000 hours at +25°C 150 ppm Thermal Hysteresis (Note 4) 140 ppm DYNAMIC CHARACTERISTICS Noise Voltage Ripple Rejection Turn-On Settling Time eOUT f = 0.1Hz to 10Hz 30 µVP-P f = 10Hz to 1kHz 115 µVRMS 43 dB 450 µs ∆VOUT/∆VIN VIN = 2.5V ±200mV, f = 120Hz tR To VOUT = 0.1% of final value INPUT Supply Voltage Range VIN Supply Current IIN Change in Supply Current 2 IIN/VIN 2.5 VIN = 2.5V to 12.6V _______________________________________________________________________________________ 12.6 V 5.25 µA 1.5 µA/V Ultra-Low-Power Series Voltage Reference (VIN = 2.7V, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX MAX6129A (±0.4%) 2.4900 2.5000 2.5100 MAX6129B (±1%) 2.4750 2.5000 2.5250 UNITS OUTPUT Output Voltage VOUT Output Voltage Temperature Coefficient (Notes 2, 3) TCVOUT ∆VOUT/∆VIN Line Regulation ∆VOUT/∆IOUT Load Regulation Dropout Voltage (Note 5) Output Short-Circuit Current VIN - VOUT MAX6129A 40 MAX6129B 100 VIN = 2.7V to 12.6V 30 230 IOUT = 0 to 4mA 0.1 0.6 IOUT = 0 to -1mA 2.5 6.2 IOUT = 0 100 IOUT = 4mA 200 ISC ∆VOUT/time Long-Term Stability TA = +25°C Thermal Hysteresis V ppm/°C µV/V µV/µA mV 60 mA 1000 hours at +25°C 150 ppm (Note 4) 140 ppm f = 0.1Hz to 10Hz 39 µVP-P µVRMS DYNAMIC CHARACTERISTICS Noise Voltage eOUT Ripple Rejection Turn-On Settling Time f = 10Hz to 1kHz 137 ∆VOUT/∆VIN VIN = 2.7V ±200mV, f = 120Hz 34 dB tR To VOUT = 0.1% of final value 700 ms INPUT Supply Voltage Range VIN Supply Current IIN Change in Supply Current IIN/VIN 2.7 VIN = 2.7V to 12.6V 12.6 V 5.75 µA 1.5 µA/V _______________________________________________________________________________________ 3 MAX6129 ELECTRICAL CHARACTERISTICS—MAX6129_25 (VOUT = 2.500V) MAX6129 Ultra-Low-Power Series Voltage Reference ELECTRICAL CHARACTERISTICS—MAX6129_30 (VOUT = 3.000V) (VIN = 3.2V, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX MAX6129A (±0.4%) 2.9880 3.0000 3.0120 MAX6129B (±1%) 2.9700 3.0000 3.0300 UNITS OUTPUT Output Voltage Output Voltage Temperature Coefficient (Notes 2, 3) Line Regulation Load Regulation Dropout Voltage (Note 5) Output Short-Circuit Current VOUT TCVOUT TA = +25°C MAX6129A 40 MAX6129B 100 ∆VOUT/∆VIN VIN = 3.2V to 12.6V ∆VOUT/ ∆IOUT VIN - VOUT 15 250 IOUT = 0 to 4mA 0.1 0.6 IOUT = 0 to -1mA 2.4 6.5 IOUT = 0 100 IOUT = 4mA 200 ISC V ppm/°C µV/V µV/µA mV 25 mA Long-Term Stability ∆VOUT/time 1000 hours at +25°C 150 ppm Thermal Hysteresis (Note 4) 140 ppm f = 0.1Hz to 10Hz 50 µVP-P f = 10Hz to 1kHz 161 µVRMS ∆VOUT/∆VIN VIN = 3.2V ±200mV, f = 120Hz 37 dB 775 µs DYNAMIC CHARACTERISTICS Noise Voltage Ripple Rejection Turn-On Settling Time eOUT tR To VOUT = 0.1% of final value INPUT Supply Voltage Range VIN Supply Current IIN Change in Supply Current 4 IIN/VIN 3.2 VIN = 3.2V to 12.6V _______________________________________________________________________________________ 12.6 V 6.75 µA 1.5 µA/V Ultra-Low-Power Series Voltage Reference (VIN = 3.5V, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS OUTPUT Output Voltage VOUT Output Voltage Temperature Coefficient (Notes 2, 3) TCVOUT Line Regulation ∆VOUT/∆VIN Load Regulation ∆VOUT/∆IOUT Dropout Voltage (Note 5) Output Short-Circuit Current VIN - VOUT MAX6129A (±0.4%) 3.2868 3.3000 3.3132 MAX6129B (±1%) 3.2670 3.3000 3.3330 MAX6129A 40 MAX6129B 100 VIN = 3.5V to 12.6V 30 270 IOUT = 0 to 4mA 0.1 0.6 IOUT = 0 to -1mA 2.4 7 IOUT = 0 100 IOUT = 4mA 200 ISC ∆VOUT/time Long-Term Stability TA = +25°C Thermal Hysteresis V ppm/°C µV/V µV/µA mV 25 mA 1000 hours at +25°C 150 ppm (Note 4) 140 ppm f = 0.1Hz to 10Hz 56 µVP-P µVRMS DYNAMIC CHARACTERISTICS Noise Voltage eOUT Ripple Rejection Turn-On Settling Time f = 10Hz to 1kHz 174 ∆VOUT/∆VIN VIN = 3.5V ±200mV, f = 120Hz 38 dB tR To VOUT = 0.1% of final value 1 ms INPUT Supply Voltage Range VIN Supply Current IIN Change in Supply Current IIN/VIN 3.5 VIN = 3.5V to 12.6V 12.6 V 7.25 µA 1.5 µA/V _______________________________________________________________________________________ 5 MAX6129 ELECTRICAL CHARACTERISTICS—MAX6129_33 (VOUT = 3.300V) MAX6129 Ultra-Low-Power Series Voltage Reference ELECTRICAL CHARACTERISTICS—MAX6129_41 (VOUT = 4.096V) (VIN = 4.3V, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX MAX6129A (±0.4%) 4.0796 4.0960 4.1124 MAX6129B (±1%) 4.0550 4.0960 4.1370 UNITS OUTPUT Output Voltage Output Voltage Temperature Coefficient (Notes 2, 3) Line Regulation Load Regulation Dropout Voltage (Note 5) Output Short-Circuit Current Long-Term Stability VOUT TCVOUT ∆VOUT/∆VIN ∆VOUT/∆IOUT VIN - VOUT TA = +25°C MAX6129A 40 MAX6129B 100 VIN = 4.3V to 12.6V 30 310 IOUT = 0 to 4mA 0.1 0.6 IOUT = 0 to -1mA 2.5 8.5 IOUT = 0 100 IOUT = 4mA 200 ISC ∆VOUT/time Thermal Hysteresis V ppm/°C µV/V µV/µA mV 25 mA 1000 hours at +25°C 150 ppm (Note 4) 140 ppm f = 0.1Hz to 10Hz 72 µVP-P µVRMS DYNAMIC CHARACTERISTICS Noise Voltage Ripple Rejection Turn-On Settling Time eOUT f = 10Hz to 1kHz 210 ∆VOUT/∆VIN VIN = 4.3V ±200mV, f = 120Hz 36 dB tR To VOUT = 0.1% of final value 1.2 ms INPUT Supply Voltage Range VIN Supply Current IIN Change in Supply Current 6 IIN/VIN 4.3 VIN = 4.3V to 12.6V _______________________________________________________________________________________ 12.6 V 8.75 µA 1.5 µA/V Ultra-Low-Power Series Voltage Reference (VIN = 5.2V, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX MAX6129A (±0.4%) 4.9800 5.0000 5.0200 MAX6129B (±1%) 4.9500 5.0000 5.0500 UNITS OUTPUT Output Voltage VOUT Output Voltage Temperature Coefficient (Notes 2, 3) TCVOUT TA = +25°C MAX6129A 40 MAX6129B 100 ∆VOUT/∆VIN VIN = 5.2V to 12.6V Line Regulation ∆VOUT/ ∆IOUT Load Regulation Dropout Voltage (Note 5) Output Short-Circuit Current VIN - VOUT 34 375 IOUT = 0 to 4mA 0.3 0.8 IOUT = 0 to -1mA 3.3 9 IOUT = 0 100 IOUT = 4mA 200 ISC V ppm/°C µV/V µV/µA mV 25 mA Long-Term Stability ∆VOUT/time 1000 hours at +25°C 150 ppm Thermal Hysteresis (Note 4) 140 ppm f = 0.1Hz to 10Hz 90 µVP-P f = 10Hz to 1kHz 245 µVRMS ∆VOUT/∆VIN VIN = 5.2V ±200mV, f = 120Hz 38 dB 1.4 ms DYNAMIC CHARACTERISTICS Noise Voltage eOUT Ripple Rejection Turn-On Settling Time tR To VOUT = 0.1% of final value INPUT Supply Voltage Range VIN Supply Current IIN Change in Supply Current IIN/VIN 5.2 VIN = 5.2V to 12.6V 12.6 V 10.5 µA 1.5 µA/V MAX6129 is 100% production tested at TA = +25°C and is guaranteed by design for TA = TMIN to TMAX as specified. Temperature coefficient is defined by box method: (VMAX - VMIN)/(∆T ✕ V+25°C). Not production tested. Guaranteed by design. Thermal hysteresis is defined as the change in TA = +25°C output voltage before and after temperature cycling of the device (from TA = TMIN to TMAX). Initial measurement at TA = +25°C is followed by temperature cycling the device to TA = +85°C then to TA = -40°C and another measurement at TA = +25°C is compared to the original measurement at TA = +25°C. Note 5: Dropout voltage is the minimum input voltage at which VOUT changes by 0.1% from VOUT at rated VIN and is guaranteed by Load Regulation Test. Note 1: Note 2: Note 3: Note 4: _______________________________________________________________________________________ 7 MAX6129 ELECTRICAL CHARACTERISTICS—MAX6129_50 (VOUT = 5.000V) Typical Operating Characteristics (VIN = 2.5V for MAX_EUK21, VIN = 3.2V for MAX_EUK30, and VIN = 5.2V for MAX_EUK50, IOUT = 0, TA = +25°C, unless otherwise noted.) 2.044 5.006 2.999 2.997 2.995 MAX6129 toc03 3 TYPICAL UNITS 3.001 OUTPUT VOLTAGE (V) 2.046 OUTPUT VOLTAGE vs. TEMPERATURE (VOUT = 5V) 3 TYPICAL UNITS 5.004 5.002 OUTPUT VOLTAGE (V) 3 TYPICAL UNITS 2.048 OUTPUT VOLTAGE (V) 3.003 MAX6129 toc01 2.050 OUTPUT VOLTAGE vs. TEMPERATURE (VOUT = 3V) MAX6129 toc02 OUTPUT VOLTAGE vs. TEMPERATURE (VOUT = 2.048V) 5.000 4.998 4.996 4.994 4.992 2.042 2.993 4.990 2.040 2.991 -40 -15 10 35 85 60 -15 10 -40 85 60 -15 10 35 60 85 TEMPERATURE (°C) SUPPLY CURRENT vs. INPUT VOLTAGE SUPPLY CURRENT vs. TEMPERATURE DROPOUT VOLTAGE vs. SOURCE CURRENT (VOUT = 2.048V) VOUT = 3V VOUT = 2.048V 4 5.5 VOUT = 3V 5.0 4.5 4.0 VOUT = 2.048V 3.5 VOUT = 5V 0.14 0.10 0.08 0.06 0.02 0 2.5 0 1 2 3 4 5 6 7 8 9 10 11 12 13 0.12 0.04 3.0 0 MAX6129 toc06 VOUT = 5V DROPOUT VOLTAGE (V) SUPPLY CURRENT (µA) 8 6 6.5 6.0 0.16 MAX6129 toc05 7.0 MAX6129 toc04 10 2 -40 -15 10 35 1 0 85 60 2 3 4 5 INPUT VOLTAGE (V) TEMPERATURE (°C) SOURCE CURRENT (mA) DROPOUT VOLTAGE vs. SOURCE CURRENT (VOUT = 3V) DROPOUT VOLTAGE vs. SOURCE CURRENT (VOUT = 5V) LOAD REGULATION (VOUT = 2.048V) 0.08 0.07 0.06 0.05 0.04 0.03 0.07 0.06 0.05 0.04 0.03 2.0515 2.0510 2.0505 2.0500 2.0495 2.0490 2.0485 0.02 2.0480 0.01 0.01 2.0475 0 0 0.02 0 1 2 3 4 5 SOURCE CURRENT (mA) 6 7 7 MAX6129 toc09 0.08 DROPOUT VOLTAGE (V) 0.09 6 2.0520 OUTPUT VOLTAGE (V) 0.10 MAX6129 toc08 0.09 MAX6129 toc07 0.11 8 35 TEMPERATURE (°C) 12 SUPPLY CURRENT (µA) 4.988 -40 TEMPERATURE (°C) 14 DROPOUT VOLTAGE (V) MAX6129 Ultra-Low-Power Series Voltage Reference 2.0470 0 1 2 3 4 5 SOURCE CURRENT (mA) 6 7 -2 -1 0 1 2 3 4 OUTPUT CURRENT (mA) _______________________________________________________________________________________ 5 6 7 Ultra-Low-Power Series Voltage Reference 2.04786 2.04784 2.04782 2.04780 2.04778 3.0045 3.0040 3.0035 3.0030 3.0025 2.04776 3.0020 2.04774 3.0015 2.04772 5.5 7.0 8.5 10.0 11.5 13.0 3.00155 -2 -1 0 1 2 3 4 5 6 3 7 4 5 6 7 8 9 10 11 12 13 OUTPUT CURRENT (mA) INPUT VOLTAGE (V) LOAD REGULATION (VOUT = 5V) LINE REGULATION (VOUT = 5V) POWER-SUPPLY REJECTION RATIO vs. FREQUENCY (VOUT = 2.048V) 5.0035 5.0030 5.0025 5.0020 -20 5.00074 5.00072 5.00070 5.00068 5.0010 5.00066 1 2 3 4 5 6 -50 -60 5 7 -30 -40 5.00064 0 -10 5.00076 5.0015 5.0005 MAX6129 toc15 5.00078 OUTPUT VOLTAGE (V) 5.0040 0 MAX6129 toc14 5.00080 MAX6129 toc13 5.0045 -1 3.00165 INPUT VOLTAGE (V) 5.0050 6 7 8 9 10 11 12 13 0.1 1 10 1000 100 OUTPUT CURRENT (mA) INPUT VOLTAGE (V) FREQUENCY (kHz) POWER-SUPPLY REJECTION RATIO vs. FREQUENCY (VOUT = 3V) POWER-SUPPLY REJECTION RATIO vs. FREQUENCY (VOUT = 5V) LINE-TRANSIENT RESPONSE (VOUT = 2.048V) 0 MAX6129 toc16 0 -10 MAX6129 toc18 MAX6129 toc17 -2 3.00170 PSRR (dB) 4.0 3.00175 3.00160 3.0010 2.5 OUTPUT VOLTAGE (V) MAX6129 toc11 3.0050 OUTPUT VOLTAGE (V) 2.04788 3.00180 OUTPUT VOLTAGE (V) 2.04790 OUTPUT VOLTAGE (V) 3.0055 MAX6129 toc10 2.04792 -5 -10 3V VIN 200mV/div AC-COUPLED -15 PSRR (dB) -20 PSRR (dB) LINE REGULATION (VOUT = 3V) LOAD REGULATION (VOUT = 3V) MAX6129 toc12 LINE REGULATION (VOUT = 2.048V) MAX6129 Typical Operating Characteristics (continued) (VIN = 2.5V for MAX_EUK21, VIN = 3.2V for MAX_EUK30, and VIN = 5.2V for MAX_EUK50, IOUT = 0, TA = +25°C, unless otherwise noted.) -30 -40 2.5V -20 -25 -30 -35 VOUT 200mV/div AC-COUPLED 2.048V -40 -50 -45 -60 -50 0.1 1 10 FREQUENCY (kHz) 100 1000 0.1 1 10 100 1000 200µs/div FREQUENCY (kHz) _______________________________________________________________________________________ 9 MAX6129 Ultra-Low-Power Series Voltage Reference Typical Operating Characteristics (continued) (VIN = 2.5V for MAX_EUK21, VIN = 3.2V for MAX_EUK30, and VIN = 5.2V for MAX_EUK50, IOUT = 0, TA = +25°C, unless otherwise noted.) LINE-TRANSIENT RESPONSE (VOUT = 3V) LINE-TRANSIENT RESPONSE (VOUT = 5V) MAX6129 toc19 3.7V MAX6129 toc20 VIN 200mV/div AC-COUPLED 3.2V 5.7V VIN 200mV/div AC-COUPLED 5.2V VOUT 100mV/div AC-COUPLED 5V VOUT 200mV/div AC-COUPLED 3V 200µs/div 200µs/div LOAD-TRANSIENT RESPONSE (SOURCING, VOUT = 2.048V) LOAD-TRANSIENT RESPONSE (SINKING, VOUT = 2.048V) MAX6129 toc21 MAX6129 toc22 COUT = 0 COUT = 0 IOUT 10mA/div 4mA 0 VOUT 500mV/div AC-COUPLED 2.048V IOUT 2mA/div 0 -1mA VOUT 500mV/div AC-COUPLED 2.048V 100µs/div 1ms/div LOAD-TRANSIENT RESPONSE (SOURCING, VOUT = 2.048V) LOAD-TRANSIENT RESPONSE (SINKING, VOUT = 2.048V) MAX6129 toc23 MAX6129 toc24 COUT = 1µF COUT = 1µF IOUT 10mA/div 4mA 0 VOUT 500mV/div AC-COUPLED 2.048V 400µs/div 10 0 -1mA IOUT 2mA/div VOUT 500mV/div AC-COUPLED 2.048V 1ms/div ______________________________________________________________________________________ Ultra-Low-Power Series Voltage Reference LOAD-TRANSIENT RESPONSE (SOURCING, VOUT = 5V) LOAD-TRANSIENT RESPONSE (SINKING, VOUT = 5V) MAX6129 toc25 MAX6129 toc26 COUT = 0 COUT = 0 IOUT 10mA/div 4mA 0 0 IOUT 1mA/div -1mA VOUT 500mV/div AC-COUPLED 5V VOUT 1V/div AC-COUPLED 5V 400µs/div 2ms/div LOAD-TRANSIENT RESPONSE (SOURCING, VOUT = 5V) LOAD-TRANSIENT RESPONSE (SINKING, VOUT = 5V) MAX6129 toc27 MAX6129 toc28 COUT = 1µF COUT = 1µF IOUT 10mA/div 4mA 0 0 IOUT 1mA/div -1mA VOUT 200mV/div AC-COUPLED 6V VOUT 1V/div AC-COUPLED 5V 400µs/div 2ms/div TURN-ON TRANSIENT (VOUT = 2.048V) TURN-ON TRANSIENT (VOUT = 3V) MAX6129 toc29 2.5V MAX6129 toc30 VIN 1V/div 3.2V VIN 2V/div 0 0 3V 2.048V VOUT 1V/div VOUT 1V/div 0 0 200µs/div 200µs/div ______________________________________________________________________________________ 11 MAX6129 Typical Operating Characteristics (continued) (VIN = 2.5V for MAX_EUK21, VIN = 3.2V for MAX_EUK30, and VIN = 5.2V for MAX_EUK50, IOUT = 0, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VIN = 2.5V for MAX_EUK21, VIN = 3.2V for MAX_EUK30, and VIN = 5.2V for MAX_EUK50, IOUT = 0, TA = +25°C, unless otherwise noted.) TURN-ON TRANSIENT (VOUT = 5V) 0.1Hz TO 10Hz OUTPUT NOISE (VOUT = 3V) 0.1Hz TO 10Hz OUTPUT NOISE (VOUT = 2.048V) MAX6129 toc31 MAX6129 toc33 MAX6129 toc32 5.2V VIN 2V/div VOUT 10µV/div VOUT 10µV/div 0 5V VOUT 2V/div 0 400µs/div 1s/div 1s/div 0.1Hz TO 10Hz OUTPUT NOISE (VOUT = 5V) NOISE vs. FREQUENCY (VOUT = 2.048V) NOISE vs. FREQUENCY (VOUT = 3V) MAX6129 toc35 4.0 3.0 NOISE (µVRMS/√Hz) VOUT 20µV/div NOISE (µVRMS/√Hz) 3.5 2.5 2.0 1.5 1.0 0.5 0 1s/div 0 10 20 30 40 50 FREQUENCY (kHz) 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 MAX6129 toc36 MAX6129 toc34 0 10 20 MAX6129 toc37 20 18 16 14 12 10 8 6 4 2 0 0 10 20 30 40 50 FREQUENCY (kHz) 12 30 FREQUENCY (kHz) NOISE vs. FREQUENCY (VOUT = 5V) NOISE (µVRMS/√Hz) MAX6129 Ultra-Low-Power Series Voltage Reference ______________________________________________________________________________________ 40 50 Ultra-Low-Power Series Voltage Reference PIN NAME FUNCTION 1 IN 2 GND Positive Voltage Supply Ground 3, 4 N.C. Internally connected. Leave unconnected or connect to ground. 5 OUT Reference Output Supply Current The quiescent supply current of the series-mode MAX6129 is very small, 5.25µA (max), and is very stable against changes in the supply voltage with only 1.5µA/V (max) variation with supply voltage. The MAX6129 family draws load current from the input voltage source only when required, so supply current is not wasted and efficiency is maximized at all input voltages. This improved efficiency reduces power dissipation and extends battery life. Applications Information Input Bypassing The MAX6129 does not require an input bypass capacitor. For improved transient performance, bypass the input to ground with a 0.1µF ceramic capacitor. Place the capacitor as close to IN as possible. Load Capacitance The MAX6129 does not require an output capacitor for stability. The MAX6129 is stable driving capacitive loads from 0 to 100pF and 0.1µF to 10µF when sourcing current and from 0 to 0.4µF when sinking current. In applications where the load or the supply can experience step changes, an output capacitor reduces the amount of overshoot (undershoot) and improves the circuit’s transient response. Many applications do not require an external capacitor, and the MAX6129 offers a significant advantage in applications where board space is critical. Output Thermal Hysteresis Output thermal hysteresis is the change of output voltage at T A = +25°C before and after the device is cycled over its entire operating temperature range. Hysteresis is caused by differential package stress appearing across the device. Temperature Coefficient vs. Operating Temperature Range for a 1LSB 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 1 shows the maximum allowable reference voltage temperature coefficient to keep the conversion error to less than 1LSB, 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. 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 10 OPERATING TEMPERATURE RANGE (TMAX - TMIN) (°C) 20 BIT 100 Figure 1. Temperature Coefficient vs. Operating Temperature Range for a 1LSB Maximum Error ______________________________________________________________________________________ 13 MAX6129 Pin Description MAX6129 Ultra-Low-Power Series Voltage Reference VIN 2VIN VCC V+ IN MAX681 GND MAX6129 V- +REF OUTPUT OUT 1MΩ V+ GND -2VIN 1MΩ 10nF MAX480 -REF OUTPUT V- Figure 2. Positive and Negative References from a Single 3V/5V Supply Selector Guide OUTPUT VOLTAGE (V) INITIAL ACCURACY (%) MAX6129AEUK21 2.048 MAX6129BEUK21 2.048 MAX6129AEUK25* 2.500 MAX6129BEUK25 MAX6129AEUK30 MAX6129BEUK30 TEMPERATURE COEFFICIENT (ppm/°C) TOP MARK 0.4 40 ADRM 1 100 ADRN 0.4 40 ADRO 2.500 1 100 ADRP 3.000 0.4 40 ADRQ 3.000 1 100 ADRR MAX6129AEUK33 3.300 0.4 40 ADRW MAX6129BEUK33 3.300 1 100 ADRX MAX6129AEUK41 4.096 0.4 40 ADRS MAX6129BEUK41 4.096 1 100 ADRT MAX6129AEUK50 5.000 0.4 40 ADRU MAX6129BEUK50 5.000 1 100 ADRV PART *Future product—contact factory for availability. 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. Turn-On Time These devices typically turn on and settle to within 0.1% of their final value in less than 1.4ms. The turn-on time increases when heavily loaded and operating close to dropout. 14 Positive and Negative Low-Power Voltage Reference Figure 2 shows a typical method for developing a bipolar reference. The circuit uses a MAX681 voltage doubler/inverter charge-pump converter to power a MAX480, creating a positive as well as a negative reference voltage. Chip Information TRANSISTOR COUNT: 30 PROCESS: BiCMOS ______________________________________________________________________________________ Ultra-Low-Power Series Voltage Reference SOT5L.EPS 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 15 © 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. MAX6129 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.)