19-3142; Rev 5; 11/09 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference Features The single MAX4036/MAX4037 and dual MAX4038/ MAX4039 operational amplifiers operate from a single +1.4V to +3.6V (without reference) or +1.8V to +3.6V (with reference) supply and consume only 800nA of supply current per amplifier, and 1.1µA for the optional reference. The MAX4036/MAX4038 feature a common-mode input voltage range from 0V to VDD - 0.4V at VDD = 1.4V. The MAX4037/MAX4039 feature a 1.232V voltage reference capable of sourcing 100µA and sinking 20µA. The MAX4036–MAX4039s’ rail-to-rail outputs drive 5kΩ loads to within 25mV of the rails. Ultra-low supply current, low operating voltage, and rail-to-rail outputs make the MAX4036–MAX4039 ideal for use in single-cell lithium-ion (Li+), or two-cell NiCd/NiMH/alkaline battery-powered applications. The MAX4036 is available in an SC70 package, the MAX4037 in a SOT23 package, and the MAX4038/ MAX4039 in UCSP™, µMAX®, and TDFN packages. ♦ Ultra-Low 800nA per Amplifier Supply Current ♦ Ultra-Low 1.4V Supply Voltage Operation (1.8V for MAX4037/MAX4039) ♦ Rail-to-Rail Outputs Drive 5kΩ and 5000pF Load ♦ 1.232V ±0.5%, 120ppm/°C (max) Reference (MAX4037/MAX4039) ♦ No External Reference Bypass Capacitor Required ♦ No Phase Reversal for Overdriven Inputs ♦ Low 1.0pA (typ) Input Bias Current ♦ Low 200μV Input Offset Voltage ♦ Unity-Gain Stable ♦ Available in Tiny UCSP, SC70, SOT23, TDFN, and μMAX Packages ♦ Available in -40°C to +125°C Temperature Range (MAX4036A/MAX4038A) Ordering Information Applications Battery-Powered/Solar-Powered Systems TEMP RANGE PINPACKAGE MAX4036EXK-T -40°C to +85°C 5 SC70 MAX4036AAXK+T -40°C to +125°C 5 SC70 MAX4037EUT-T -40°C to +85°C 6 SOT23 ABRX MAX4038ETA-T -40°C to +85°C 8 TDFN-EP* AGO PART Portable Medical Instrumentation Pagers and Cell Phones Micropower Thermostats and Potentiostats Electrometer Amplifiers TOP MARK AFR ASN Remote Sensor Amplifiers MAX4038EUA -40°C to +85°C 8 µMAX — Active Badges MAX4038EBL-T -40°C to +85°C 9 UCSP AEG pH Meters MAX4038AAUA -40°C to +125°C 8 µMAX — Pin Configurations and Selector Guide appear at end of data sheet. µMAX is a registered trademark and UCSP is a trademark of Maxim Integrated Products, Inc. +Denotes a lead(Pb)-free/RoHS-compliant package. -Denotes a package containing lead. *EP = Exposed pad. Ordering Information continued at end of data sheet. Functional Diagram Typical Operating Circuit 3V OUTA MAX4039 VDD INAOUTA VDD OUTB INA- INB- INA+ REF INB+ INB+ SENSOR MAX4039 INB- INA+ REF OUTB REF VSS ADC VSS THREE-ELECTRODE POTENTIOSTAT APPLICATION ________________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. MAX4036–MAX4039 General Description MAX4036–MAX4039 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference ABSOLUTE MAXIMUM RATINGS VDD to VSS .............................................................-0.3V to +4.0V INA+, INB+, INA-, INB-, IN+, IN-, OUTA, OUTB, OUT, REF .........................(VSS - 0.3V) to (VDD + 0.3V) OUTA, OUTB, OUT, REF Shorted to VSS or VDD .......Continuous Maximum Continuous Power Dissipation (TA = +70°C) 5-Pin SC70 (derate 3.1mW/°C above +70°C) ..............247mW 6-Pin SOT23 (derate 8.7mW/°C above +70°C)............696mW 8-Pin µMAX (derate 4.5mW/°C above +70°C) .............362mW 8-Pin TDFN (derate 24.4mW/°C above +70°C) .........1951mW 9-Bump UCSP (derate 5.2mW/°C above +70°C).........412mW 10-Pin µMAX (derate 5.6mW/°C above +70°C) ...........444mW 10-Pin TDFN (derate 24.4mW/°C above +70°C) .......1951mW Operating Temperature Range MAX403_E_ _...................................................-40°C to +85°C MAX403_A_ _ ................................................-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 (VDD = +3V, VSS = VCM = 0V, VOUT_ = VDD/2, RL to VDD/2, CL = 15pF, TA = +25°C, unless otherwise specified.) PARAMETER Supply Voltage Range SYMBOL VDD CONDITIONS TYP MAX MAX4036/MAX4038, guaranteed by PSRR tests 1.4 3.6 MAX4037/MAX4039, guaranteed by PSRR and line regulation tests 1.8 3.6 UNITS V MAX4036 MAX4037 Supply Current MIN IDD MAX4038 MAX4039 VDD = 1.4V 0.8 1.2 VDD = 3.6V 0.9 1.3 VDD = 1.8V 1.9 2.4 VDD = 3.6V 2.0 2.5 VDD = 1.4V 1.7 2.3 µA VDD = 3.6V 1.9 2.5 VDD = 1.8V 2.8 4.0 VDD = 3.6V 3.0 4.1 ±0.2 ±2.0 mV OPERATIONAL AMPLIFIERS Input Offset Voltage Input Bias Current Input Offset Current Input Common-Mode Voltage Range Common-Mode Rejection Ratio Power-Supply Rejection Ratio 2 VOS IB (Note 1) ±1.0 ±10 pA IOS (Note 1) ±0.3 ±20 pA VCM CMRR PSRR Guaranteed by CMRR test VDD = 1.4V (MAX4036/MAX4038 only) VSS VDD 0.4 VDD = 1.8V VSS VDD 0.3 VDD = 3.3V VSS VDD 0.2 VDD = 1.4V, VSS ≤ VCM ≤ (VDD - 0.4V) (MAX4036/MAX4038 only) 50 70 VDD = 1.8V, VSS ≤ VCM ≤ (VDD - 0.3V) 50 70 VDD = 3.3V, VSS ≤ VCM ≤ (VDD - 0.2V) 56 76 1.4V ≤ VDD ≤ 3.6V (MAX4036/MAX4038 only) 62 82 1.8V ≤ VDD ≤ 3.6V 62 84 _______________________________________________________________________________________ V dB dB Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference (VDD = +3V, VSS = VCM = 0V, VOUT_ = VDD/2, RL to VDD/2, CL = 15pF, TA = +25°C, unless otherwise specified.) PARAMETER SYMBOL Large-Signal Voltage Gain AVOL Output Voltage Swing High VDD - VOH Output Voltage Swing Low VOL - VSS CONDITIONS MIN TYP RL = 100kΩ, 50mV ≤ VOUT ≤ (VDD - 50mV) 80 108 RL = 5kΩ, 150mV ≤ VOUT ≤ (VDD - 150mV) 78 105 MAX dB RL = 100kΩ 2 5 RL = 5kΩ 25 50 RL = 100kΩ 2 5 RL = 5kΩ 25 50 mV mV Output Short-Circuit Current ISCO ±13 mA Gain-Bandwidth Product GBW 4 kHz Phase Margin θM 90 Degrees Slew Rate SR 4 V/ms Power-On Time tON (Note 3) 0.25 ms en f = 1kHz 500 nV/√Hz AVCL = 1V/V, no sustained oscillations 5000 pF Input Noise-Voltage Density Capacitive-Load Stability CLOAD To VDD or VSS UNITS REFERENCE (MAX4037/MAX4039) Reference Voltage VREF Line Regulation ΔVREF/ ΔVDD Load Regulation ΔVREF/ ΔILOAD Reference Output Voltage Noise Output Short-Circuit Current Capacitive-Load Stability Range en ISCR CLOAD 1.226 1.232 VDD = +1.8V to +3.6V 1.238 V 0.3 %/V 0 ≤ ILOAD ≤ 100µA, sourcing 0.0015 -20µA ≤ ILOAD ≤ 0, sinking 0.0075 0.1Hz to 10Hz 60 Short to VDD 0.25 Short to VSS 1.9 (Note 1) 0 %/µA µVP-P mA 250 pF ELECTRICAL CHARACTERISTICS (VDD = +3V, VSS = VCM = 0V, VOUT_ = VDD/2, RL to VDD/2, CL = 15pF, TA = TMIN to TMAX, unless otherwise specified.) (Note 2) PARAMETER Supply Voltage Range SYMBOL VDD CONDITIONS IDD TYP MAX 1.4 3.6 MAX4037/MAX4039, guaranteed by PSRR and line regulation tests 1.8 3.6 UNITS V MAX4036 Supply Current MIN MAX4036/MAX4038, guaranteed by PSRR test MAX4036A MAX4037 VDD = 1.4V 1.7 VDD = 3.6V 1.8 VDD = 1.4V 2.0 VDD = 3.6V 2.1 VDD = 1.8V 3.1 VDD = 3.6V 3.2 µA _______________________________________________________________________________________ 3 MAX4036–MAX4039 ELECTRICAL CHARACTERISTICS (continued) MAX4036–MAX4039 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference ELECTRICAL CHARACTERISTICS (continued) (VDD = +3V, VSS = VCM = 0V, VOUT_ = VDD/2, RL to VDD/2, CL = 15pF, TA = TMIN to TMAX, unless otherwise specified.) (Note 2) PARAMETER SYMBOL CONDITIONS MAX4038 Supply Current IDD MAX4038A MAX4039 MIN TYP MAX VDD = 1.4V 2.9 VDD = 3.6V 3.2 VDD = 1.4V 3.4 VDD = 3.6V 3.7 VDD = 1.8V 5.2 VDD = 3.6V 5.3 UNITS µA OPERATIONAL AMPLIFIERS Input Offset Voltage VOS Input Offset Voltage Temperature Coefficient ±8 ±1 TCVOS Input Bias Current Input Offset Current Input Common-Mode Voltage Range ±100 pA IOS ±200 pA CMRR Power-Supply Rejection Ratio PSRR Large-Signal Voltage Gain µV/°C IB VCM Common-Mode Rejection Ratio mV AVOL Output Voltage Swing High VDD - VOH Output Voltage Swing Low VOL - VSS Guaranteed by CMRR test VDD = 1.4V (MAX4036/MAX4038 only) VSS VDD 0.4 VDD = 1.8V VSS VDD 0.4 VDD = 3.3V VSS VDD 0.2 VDD = 1.4V, VSS ≤ VCM ≤ (VDD - 0.5V) (MAX4036/MAX4038 only) 44 VDD = 1.8V, VSS ≤ VCM ≤ (VDD - 0.4V) 50 VDD = 3.3V, VSS ≤ VCM ≤ (VDD - 0.3V) 52 1.4V ≤ VDD ≤ 3.6V (MAX4036/MAX4038 only) 60 1.8V ≤ VDD ≤ 3.6V 60 RL = 100kΩ, 50mV ≤ VOUT ≤ (VDD - 50mV) 75 RL = 5kΩ, 150mV ≤ VOUT ≤ (VDD - 150mV) 73 V dB dB dB RL = 100kΩ 10 RL = 5kΩ 100 RL = 100kΩ 10 RL = 5kΩ 100 mV mV REFERENCE (MAX4037/MAX4039) MAX4037EUT-T, MAX4039ETB, MAX4039EUB MAX4039EBL-T 25 120 35 200 Reference Voltage Temperature Coefficient TCVREF Line Regulation ΔVREF/ ΔVDD Load Regulation ΔVREF/ ΔILOAD 0 ≤ ILOAD ≤ 100µA, sourcing 0.003 -20µA ≤ ILOAD ≤ 0, sinking 0.015 Capacitive-Load Stability Range CLOAD (Note 1) (Note 1) VDD = 1.8V to 3.6V 0.6 0 Note 1: Guaranteed by design. Note 2: All devices are production tested at TA = +25°C. All temperature limits are guaranteed by design. Note 3: Output settles within 1% of final value. 4 _______________________________________________________________________________________ 250 ppm/°C %/V %/µA pF Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference MAX4037 SUPPLY CURRENT vs. SUPPLY VOLTAGE AND TEMPERATURE TA = +25°C 0.8 TA = -40°C 0.4 TA = +25°C 2.5 2.0 1.5 TA = -40°C 1.0 3.0 0.5 1.4 1.8 2.2 2.6 3.0 1.5 1.0 TA = -40°C 2.1 2.4 2.7 3.0 3.3 0 3.6 1.4 1.8 2.2 2.6 3.0 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) MAX4039 SUPPLY CURRENT vs. SUPPLY VOLTAGE AND TEMPERATURE OFFSET VOLTAGE vs. COMMON-MODE VOLTAGE OFFSET VOLTAGE vs. TEMPERATURE 2 TA = -40°C 0.6 VDD = 1.8V VDD = 3.0V VDD = 1.4V 0.4 0.2 1 2.1 2.4 2.7 3.0 3.3 -0.10 2 3 -40 -15 10 35 60 85 SUPPLY VOLTAGE (V) COMMON-MODE VOLTAGE (V) TEMPERATURE (°C) INPUT BIAS CURRENT vs. TEMPERATURE INPUT BIAS CURRENT vs. COMMON-MODE VOLTAGE OP AMP POWER-SUPPLY REJECTION RATIO vs. FREQUENCY 20 VCM = 3V 10 0 VCM = 0V -15 10 35 TEMPERATURE (°C) -30 TA = +85°C 20 85 -40 -50 -60 -70 10 -80 -90 -100 0 60 -20 30 TA = +25°C -10 AV = 1V/V -10 PSRR (dB) INPUT BIAS CURRENT (pA) 30 0 MAX4036 toc09 40 MAX4036 toc07 40 -40 0 -0.30 1 0 3.6 MAX4036 toc08 1.8 0.10 -0.20 0 0 MAX4036 toc06 0.20 OFFSET VOLTAGE (mV) 3 3.4 0.30 MAX4036 toc05 0.8 OFFSET VOLTAGE (mV) TA = +25°C 1.0 MAX4036 toc04 TA = +85°C 4 INPUT BIAS CURRENT (pA) 2.0 SUPPLY VOLTAGE (V) 5 SUPPLY CURRENT (μA) 1.8 3.4 TA = +25°C 0.5 0 0 TA = +85°C 2.5 SUPPLY CURRENT (μA) TA = +85°C 1.2 TA = +85°C MAX4036 toc02 MAX4036 toc01 3.0 SUPPLY CURRENT (μA) SUPPLY CURRENT (μA) 1.6 MAX4038 SUPPLY CURRENT vs. SUPPLY VOLTAGE AND TEMPERATURE MAX4036 toc03 MAX4036 SUPPLY CURRENT vs. SUPPLY VOLTAGE AND TEMPERATURE 0 0.5 1.0 1.5 2.0 2.5 COMMON-MODE VOLTAGE (V) 3.0 10 100 1k 10k FREQUENCY (Hz) _______________________________________________________________________________________ 5 MAX4036–MAX4039 Typical Operating Characteristics (VDD = 3V, VSS = VCM = 0V, RL to VDD/2, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VDD = 3V, VSS = VCM = 0V, RL to VDD/2, TA = +25°C, unless otherwise noted.) 30 25 VOL - VSS (mV) RL = 5kΩ 100 20 15 10 RL = 5kΩ 120 AV (dB) 15 140 MAX4036 toc11 RL = 5kΩ 20 RL = 100kΩ 80 10 60 5 5 RL = 100kΩ 0 RL = 100kΩ 0 -15 10 35 60 85 40 -40 -15 10 35 60 85 0 100 200 300 400 TEMPERATURE (°C) TEMPERATURE (°C) VOL (mV) AV vs. OUTPUT SWING HIGH AV vs. TEMPERATURE CROSSTALK vs. FREQUENCY 140 MAX4036 toc13 140 RL = 5kΩ 120 0 120 500 MAX4036 toc15 -40 MAX4036 toc14 VDD - VOH (mV) 35 MAX4036 toc10 30 25 AV vs. OUTPUT SWING LOW OUTPUT VOLTAGE SWING LOW vs. TEMPERATURE MAX4036 toc12 OUTPUT VOLTAGE SWING HIGH vs. TEMPERATURE MAX4038/MAX4039 AV = 1V/V -20 100 RL = 100kΩ 80 RL = 100kΩ CROSSTALK (dB) AV (dB) AVOL (dB) RL = 5kΩ 100 80 60 -40 RL = 5kΩ -60 RL = 100kΩ 40 -80 60 20 0 0 100 200 300 400 -100 -40 500 -15 35 60 85 0 1k 0.1 10k TEMPERATURE (°C) FREQUENCY (Hz) TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY OP AMP STABILITY vs. CAPACITIVE AND RESISTIVE LOADS OP AMP SINK CURRENT vs. OUTPUT VOLTAGE 100,000 UNSTABLE REGION 1 VOUT = 2.5VP-P RL = 5kΩ TO VSS 0.1 10,000 1000 VOUT = 2.5VP-P RL = 100kΩ TO VSS STABLE REGION 0.01 0.1 1 FREQUENCY (kHz) 10 100 VDD = 3.0V 100k 10 8 6 VDD = 1.8V 4 2 RL TO VSS 0 100 0.01 VID = -100mV 12 SINK CURRENT (mA) CAPACITIVE LOAD (pF) 10 14 MAX4036 toc17 AV = 1V/V VIN_ = VDD/2 MAX4036 toc16 VDD - VOH (mV) 100 6 10 MAX4036 toc18 40 THD+N (%) MAX4036–MAX4039 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference 10k 100k RESISTIVE LOAD (Ω) 1M 0 0.6 1.2 1.8 VOUT_ (V) _______________________________________________________________________________________ 2.4 3.0 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference INPUT VOLTAGE NOISE DENSITY vs. FREQUENCY OP AMP SOURCE CURRENT vs. OUTPUT VOLTAGE SOURCE CURRENT (mA) 14 VDD = 3.0V 12 10 8 6 VDD = 1.8V 4 MAX4036 toc20 INPUT VOLTAGE NOISE (nV/√Hz) VID = +100mV 16 3500 MAX4036 toc19 18 3000 2500 2000 1500 1000 500 2 0 0 0 0.6 1.2 1.8 2.4 3.0 0.1 1 10 100 1k 10k FREQUENCY (Hz) VOUT_ (V) OP AMP SMALL-SIGNAL TRANSIENT RESPONSE AV = 1V/V CL = 250pF TO VSS RL = 1MΩ TO VSS 2.55V MAX4036 toc22 MAX4036 toc21 AV = 1V/V CL = 12pF TO VSS RL = 1MΩ TO VSS 2.55V OP AMP SMALL-SIGNAL TRANSIENT RESPONSE VIN+ VIN+ 2.45V 2.45V 2.55V 2.55V VOUT_ 2.45V VOUT_ 2.45V 40μs/div OP AMP LARGE-SIGNAL TRANSIENT RESPONSE VIN+ 1.5V AV = 1V/V CL = 12pF TO GND RL = 1MΩ TO GND VIN+ = VDD / 2 MAX4036 toc24 MAX4036 toc23 AV = 1V/V CL = 12pF TO VSS RL = 1MΩ TO VSS 2.5V OP AMP TURN-ON TRANSIENT RESPONSE 3.0V VDD 0V VOUT_ 500mV/div 100μs/div VOUT_ 50mV/div 100μs/div ________________________________________________________________________________________ 7 MAX4036–MAX4039 Typical Operating Characteristics (continued) (VDD = 3V, VSS = VCM = 0V, RL to VDD/2, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VDD = 3V, VSS = VCM = 0V, RL to VDD/2, TA = +25°C, unless otherwise noted.) GAIN AND PHASE vs. FREQUENCY GAIN 180 2 135 -2 -6 PHASE 0 -45 -20 -30 -40 1 10 100 1k RL = 5kΩ RL = 100kΩ -22 AV = 1 VOUT_ = 1VP-P CL = 12pF -26 -135 100k 10k RL = 1MΩ -14 -18 -90 AV = 1000V/V VIN_ = 1mVP-P -10 -30 100 REFERENCE VOLTAGE CHANGE vs. TIME REFERENCE VOLTAGE CHANGE vs. LOAD CURRENT 1.02 MAX4036 toc28 1.234 1.234 MAX4036 toc27 MAX4037/MAX4039 TA = +85°C 1.233 1.230 MAX4037 1.232 MAX4039 1.231 1.230 -15 10 35 60 0.98 0 85 100 200 300 400 500 600 -100 TIME (HR) TEMPERATURE (°C) REFERENCE VOLTAGE CHANGE vs. SUPPLY VOLTAGE 1.0002 0 100 1.0001 3.6V VDD 1.8V 1.0000 0.9999 0V 0.9998 TA = -40°C VREF AC-COUPLED 50mV/div TA = +25°C 0.9997 TA = +85°C 0.9996 0.9995 1.8 2.1 2.4 2.7 3.0 3.3 3.6 1ms/div VDD (V) 8 200 300 LOAD CURRENT (μA) REFERENCE LINE-TRANSIENT RESPONSE MAX4036 toc30 1.0003 NORMALIZED VREF 1.00 MAX4036 toc31 -40 TA = -40°C 0.99 1.228 1.226 TA = +25°C 1.01 NORMALIZED VREF VREF (V) 1.232 100k FREQUENCY (Hz) REFERENCE VOLTAGE vs. TEMPERATURE 1.236 10k 1k FREQUENCY (Hz) MAX4036 toc29 10 0 -10 GAIN (dB) 45 20 PHASE (DEGREES) 90 40 30 MAX4036 toc26 70 60 50 GAIN (dB) LARGE-SIGNAL GAIN vs. FREQUENCY MAX4036 toc25 80 VREF (V) MAX4036–MAX4039 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference _______________________________________________________________________________________ 400 500 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference REFERENCE LOAD-TRANSIENT RESPONSE (SINKING CURRENT) REFERENCE LOAD-TRANSIENT RESPONSE (SINKING CURRENT) MAX4036 toc33 MAX4036 toc32 0 IREF 0 IREF 2μA 20μA VREF 500mV/div VREF 500mV/div 0 0 2.5ms/div 2.5ms/div REFERENCE LOAD-TRANSIENT RESPONSE (SOURCING CURRENT) REFERENCE LOAD-TRANSIENT RESPONSE (SOURCING CURRENT) MAX4036 toc34 MAX4036 toc35 10μA 100μA IREF 0 IREF 0 VREF 500mV/div VREF 500mV/div 0 0 1ms/div 1ms/div REFERENCE TURN-ON TRANSIENT RESPONSE 0.1Hz TO 10Hz REFERENCE NOISE MAX4036 toc37 MAX4036 toc36 3V VDD 0V VREF 0V 1ms/div 1s/div 20μV/div _______________________________________________________________________________________ 9 MAX4036–MAX4039 Typical Operating Characteristics (continued) (VDD = 3V, VSS = VCM = 0V, RL to VDD/2, TA = +25°C, unless otherwise noted.) MAX4036–MAX4039 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference PIN MAX4038/ MAX4039 MAX4036/ MAX4038A MAX4037 MAX4036A µMAX*/TDFN UCSP µMAX/TDF UCSP 1 3 — — 2 3 2 4 4 — 4 1 NAME FUNCTION — — IN+ Noninverting Amplifier Input A2 5 A2 VSS Negative Power-Supply Voltage — — — IN- — — — — OUT Amplifier Output Positive Power-Supply Voltage Inverting Amplifier Input 5 6 8 C2 10 C2 VDD — 5 — — 6 B2 REF — — 1 C1 1 C1 OUTA — — 2 B1 2 B1 INA- Inverting Amplifier Input (Channel A) — — 3 A1 3 A1 INA+ Noninverting Amplifier Input (Channel A) — — 5 A3 7 A3 INB+ Noninverting Amplifier Input (Channel B) — — 6 B3 8 B3 INB- Inverting Amplifier Input (Channel B) — — 7 C3 9 C3 OUTB — — — B2 4 — N.C. — — — — — — EP (TDFN only) Reference Voltage Output Amplifier Output (Channel A) Amplifier Output (Channel B) No Connection. Not internally connected. Exposed Paddle. Solder EP to VSS or leave unconnected (TDFN packages only). *Both MAX4038/MAX4038A available in µMAX package only. Detailed Description The MAX4036–MAX4039 consume an ultra-low supply current and have rail-to-rail output stages specifically designed for low-voltage operation. The input commonmode voltage range extends from VDD - 0.4V to VSS, although full rail-to-rail input range is possible with degraded performance when operating from a supply voltage above 3.0V. The input offset voltage is typically 200µV. Low-operating supply voltage, low supply current, and rail-to-rail outputs make the MAX4036–MAX4039 an excellent choice for precision or general-purpose lowvoltage, battery-powered systems. AV = 1V/V VIN_+ 1.5V VOUT+ 1.5V Rail-to-Rail Outputs The MAX4036–MAX4039 output stages can drive a 5kΩ load and still swing to within 40mV of the rails. Figure 1 shows the output voltage swing of the MAX4036– MAX4039 configured as a unity-gain buffer, powered from a single 2.4V supply. The output for this setup typically swings from 5mV to VDD - 5mV with a 100kΩ load. 10 2ms/div 1V/div Figure 1. Rail-to-Rail Input/Output Voltage Range ______________________________________________________________________________________ Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference Power-Supply Considerations The MAX4036–MAX4039 operate from a single 1.4V (MAX4036/MAX4038) or 1.8V (MAX4037/MAX4039) to 3.6V supply. A high amplifier power-supply rejection ratio of 82dB and the excellent reference line regulation allow the devices to be powered directly from a decaying battery voltage, simplifying design and extending battery life. The MAX4036–MAX4039 are ideally suited for low-voltage battery-powered systems. The Typical Operating Characteristics show the changes in supply current and reference output as a function of supply voltage. Power-Up Settling Time The MAX4036–MAX4039 typically require 0.25ms to power-up. During this startup time, the output is indeterminate. The application circuit should allow for this initial delay. See the Typical Operating Characteristics for amplifier and reference settling time curves. Driving Capacitive Loads: Op Amps The MAX4036–MAX4039 amplifier(s) require no output capacitor for stability, and are unity-gain stable for loads up to 5000pF. Applications that require greater capacitive-drive capability should use an isolation resistor between the output and the capacitive load (Figure 2). Note that this solution reduces the gain and output voltage swing because RISO forms a voltagedivider with the load resistor. Crossover Distortion The MAX4036–MAX4039 output stages are capable of sourcing and sinking currents with orders of magnitude greater than the stages’ quiescent current, which is less than 1µA. This ability to drive heavy loads with such a small quiescent current introduces crossover RISO MAX4038 RL CL INPUT VHB VTHF VOH OUTPUT VOL Figure 3. Hysteresis distortion as the output stage passes between sinking and sourcing. In the crossover regions, the output impedance of the MAX4036–MAX4039 increases substantially, thereby changing the load-driving characteristics. The distortion can be greatly reduced by increasing the load resistance. For applications where low load resistance is required, bias the load such that the output current is always in one direction, to avoid crossover distortion. Reference Bypassing The MAX4037/MAX4039 reference requires no external capacitors. Using the MAX4036–MAX4039 as a Comparator Although optimized for use as an operational amplifier, the MAX4036–MAX4039 can be used as a rail-to-rail I/O comparator (Figures 3, 4). External hysteresis can be used to minimize the risk of output oscillation. The positive feedback circuit, shown in Figure 4, causes the input threshold to change when the output voltage changes state. Battery Monitoring Using the MAX4037/MAX4039 and Hysteresis The internal reference and low operating voltage of the MAX4037/MAX4039 make the devices ideal for batterymonitoring applications. Hysteresis can be set using resistors as shown in Figure 4, and the following design procedure: 1) Choose R3. The input bias current of IN_+ is under 100pA over temperature, so a current through R3 around 100nA maintains accuracy. The current through R3 at the trip point is VREF / R3, or 100nA for R3 = 12MΩ. 10MΩ is a good practical value. 2) AV = VTHR Choose the hysteresis voltage (VHB), the voltage between the upper and lower thresholds. In this example, choose VHB = 50mV (see Figure 3). RL =1 RL + RISO Figure 2. Using a Resistor to Isolate a Capacitive Load from the Op Amp ______________________________________________________________________________________ 11 MAX4036–MAX4039 Applications Information MAX4036–MAX4039 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference 3) Calculate R1: VHB VDD 0.5V = 10MΩ × 2.4 V = 210kΩ R3 R1 = R 3 × 4) 5) VBATT IN+ Choose the threshold voltage for VIN rising (VTHR). In this example, choose VTHR = 2.0V. Calculate R2: OUT R2 ⎡⎛ VTHR ⎞ 1 1 ⎤ − − ⎢⎜ ⎥ ⎟ R1 R 3 ⎥⎦ ⎢⎣⎝ VREF × R1⎠ 1 = ⎡⎛ 2.0V 1 1 ⎤ ⎞ − ⎟ − ⎢⎜ ⎥ 210kΩ 10MΩ ⎦ ⎣⎝ 1.2V × 210kΩ ⎠ = 325kΩ VSS REF VREF Figure 4. Battery Monitoring Selector Guide PART VIN falling: ⎛ R1 × VDD ⎞ VTHF = VTHR − ⎜ ⎟ ⎝ ⎠ R3 In this application, the MAX4036–MAX4039 supply current will vary, depending on the output state of the comparator. MAX4037 VSS Verify the threshold voltages with these formulas: VIN rising: 1 1 ⎞ ⎛ 1 VTHR = VREF × R1 × ⎜ + + ⎟ ⎝ R1 R2 R3 ⎠ VBGOOD IN- 1 R2 = 6) VDD VDD R1 NO. OF AMPLIFIERS REFERENCE MAX4036 1 — MAX4037 1 √ MAX4038 2 — MAX4039 2 √ Ordering Information (continued) PART TEMP RANGE PINPACKAGE TOP MARK Power Supplies and Layout MAX4039EBL-T -40°C to +85°C 9 UCSP AEH The MAX4036–MAX4039 operate from a single 1.4V (MAX4036/MAX4038) or 1.8V (MAX4037/MAX4039) to 3.6V power supply. Bypass VDD with a 0.1µF capacitor to ground to minimize noise. Good layout techniques optimize performance by decreasing the amount of stray capacitance to the op amp’s inputs and outputs. To decrease stray capacitance, minimize trace lengths by placing external components close to the device. MAX4039ETB-T -40°C to +85°C 10 TDFN-EP* AAN MAX4039EUB -40°C to +85°C 10 µMAX The exposed paddle (EP) on the TDFN packages of the MAX4038 and MAX4039 is internally connected to the device substrate, VSS. Connect the exposed paddle to VSS or leave EP unconnected. Running traces below the exposed paddle is not recommended. 12 — -Denotes a package containing lead. *EP = Exposed pad. Chip Information MAX4036 TRANSISTOR COUNT: 49 MAX4037 TRANSISTOR COUNT: 119 MAX4038 TRANSISTOR COUNT: 146 MAX4039 TRANSISTOR COUNT: 146 PROCESS: BiCMOS ______________________________________________________________________________________ Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference TOP VIEW 5 VDD IN+ 1 VSS 2 OUT 1 MAX4036 MAX4036A 6 VDD MAX4037 VSS 2 4 OUT IN- 3 4 IN- IN+ 3 SC70 SOT23 8 VDD OUTA 1 INA- 2 MAX4038 MAX4038A INA+ 3 5 REF VSS 4 OUTA 1 7 OUTB INA- 2 6 INB- INA+ 3 5 INB+ VSS 4 μMAX 8 VDD 7 OUTB MAX4038 6 INB5 INB+ 3mm x 3mm x 0.8mm TDFN TDFN EXPOSED PAD CONNECTED TO VSS. OUTA 1 10 VDD OUTA 1 10 VDD 9 OUTB INA- 2 8 INB- INA+ 3 4 7 INB+ N.C. 4 7 INB+ 5 6 REF VSS 5 6 REF INA- 2 INA+ 3 N.C. VSS MAX4039 μMAX 9 OUTB 8 INB- MAX4039 3mm x 3mm x 0.8mm TDFN TDFN EXPOSED PAD CONNECTED TO VSS. MAX4038 MAX4039 (BUMP SIDE DOWN) (BUMP SIDE DOWN) A INA+ VSS INB+ A INA+ VSS INB+ B INA- N.C. INB- B INA- REF INB- C OUTA VDD OUTB C OUTA VDD OUTB 2 3 2 3 1 UCSP 1 UCSP ______________________________________________________________________________________ 13 MAX4036–MAX4039 Pin Configurations Package Information For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. SC70, 5L.EPS MAX4036–MAX4039 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference PACKAGE OUTLINE, 5L SC70 21-0076 14 ______________________________________________________________________________________ E 1 1 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference 6LSOT.EPS PACKAGE OUTLINE, SOT 6L BODY 21-0058 I 1 2 ______________________________________________________________________________________ 15 MAX4036–MAX4039 Package Information (continued) For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. MAX4036–MAX4039 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference Package Information (continued) For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE OUTLINE, SOT 6L BODY 21-0058 16 ______________________________________________________________________________________ I 2 2 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference α α ______________________________________________________________________________________ 17 MAX4036–MAX4039 Package Information (continued) For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. MAX4036–MAX4039 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference Package Information (continued) For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. 18 ______________________________________________________________________________________ Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference COMMON DIMENSIONS PACKAGE VARIATIONS MIN. MAX. PKG. CODE N D2 E2 e JEDEC SPEC b A 0.70 0.80 T633-2 6 1.50±0.10 2.30±0.10 0.95 BSC MO229 / WEEA 0.40±0.05 1.90 REF D 2.90 3.10 T833-2 8 1.50±0.10 2.30±0.10 0.65 BSC MO229 / WEEC 0.30±0.05 1.95 REF E 2.90 3.10 T833-3 8 1.50±0.10 2.30±0.10 0.65 BSC MO229 / WEEC 0.30±0.05 1.95 REF 0.05 T1033-1 10 1.50±0.10 2.30±0.10 0.50 BSC MO229 / WEED-3 0.25±0.05 2.00 REF 0.40 T1033MK-1 10 1.50±0.10 2.30±0.10 0.50 BSC MO229 / WEED-3 0.25±0.05 2.00 REF 0.25 MIN. T1033-2 10 1.50±0.10 2.30±0.10 0.50 BSC MO229 / WEED-3 0.25±0.05 2.00 REF 0.20 REF. T1433-1 14 1.70±0.10 2.30±0.10 0.40 BSC ---- 0.20±0.05 2.40 REF T1433-2 14 1.70±0.10 2.30±0.10 0.40 BSC ---- 0.20±0.05 2.40 REF T1433-3F 14 1.70±0.10 2.30±0.10 0.40 BSC ---- 0.20±0.05 2.40 REF SYMBOL A1 L k A2 0.00 0.20 [(N/2)-1] x e ______________________________________________________________________________________ 19 MAX4036–MAX4039 Package Information (continued) For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. Package Information (continued) For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. 10LUMAX.EPS MAX4036–MAX4039 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference α α 20 ______________________________________________________________________________________ Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference 9LUCSP, 3x3.EPS PACKAGE OUTLINE, 3x3 UCSP 21-0093 L 1 1 ______________________________________________________________________________________ 21 MAX4036–MAX4039 Package Information (continued) For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. MAX4036–MAX4039 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference Revision History REVISION NUMBER REVISION DATE 5 11/09 DESCRIPTION Updated TOC 20 PAGES CHANGED 7 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. 22 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.