19-3142; Rev 2; 11/04 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference 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. All devices are specified over the -40°C to +85°C extended temperature range. Features ♦ 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 Ordering Information PART TEMP RANGE PINPACKAGE Battery-Powered/Solar-Powered Systems MAX4036EXK-T -40°C to +85°C 5 SC70-5 Portable Medical Instrumentation MAX4037EUT-T -40°C to +85°C 6 SOT23-6 ABRX MAX4038ETA -40°C to +85°C 8 TDFN-EP* AGO MAX4038EUA -40°C to +85°C 8 µMAX MAX4038EBL-T -40°C to +85°C 9 UCSP-9 MAX4039EBL-T -40°C to +85°C 9 UCSP-9 AEH MAX4039ETB -40°C to +85°C 10 TDFN-EP* AAN MAX4039EUB -40°C to +85°C 10 µMAX Applications Pagers and Cell Phones Micropower Thermostats and Potentiostats Electrometer Amplifiers Remote Sensor Amplifiers Active Badges pH Meters TOP MARK AFR — AEG — *EP = Exposed paddle. µMAX is a registered trademark and UCSP is a trademark of Maxim Integrated Products, Inc. Pin Configurations and Selector Guide appear at end of data sheet. Typical Operating Circuit Functional Diagram 3V OUTA MAX4039 VDD INAOUTA VDD OUTB INA- INA+ REF SENSOR MAX4039 INB- INBINA+ REF INB+ OUTB INB+ REF ADC VSS VSS THREE-ELECTRODE POTENTIOSTAT APPLICATION ________________________________________________________________ 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 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 ...........................-40°C to +85°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 Output Short-Circuit Current ISCO Gain-Bandwidth Product GBW MIN TYP RL = 100kΩ, 50mV ≤ VOUT ≤ (VDD - 50mV) CONDITIONS 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 To VDD or VSS UNITS mV mV ±13 mA 4 kHz Phase Margin θM 90 Degrees Slew Rate SR 0.4 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 REFERENCE (MAX4037/MAX4039) Reference Voltage VREF Line Regulation ∆VREF/ ∆VDD Load Regulation ∆VREF/ ∆ILOAD 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 TYP MAX 1.4 3.6 MAX4037/MAX4039, guaranteed by PSRR and line regulation tests 1.8 3.6 UNITS V MAX4036 MAX4037 Supply Current MIN MAX4036/MAX4038, guaranteed by PSRR test IDD MAX4038 MAX4039 VDD = 1.4V 1.7 VDD = 3.6V 1.8 VDD = 1.8V 3.1 VDD = 3.6V 3.2 VDD = 1.4V 2.9 VDD = 3.6V 3.2 VDD = 1.8V 5.2 VDD = 3.6V 5.3 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 MIN TYP MAX UNITS ±8 mV OPERATIONAL AMPLIFIERS Input Offset Voltage VOS Input Offset Voltage Temperature Coefficient ±1 TCVOS Input Bias Current Input Offset Current Input Common-Mode Voltage Range IB ±100 pA IOS ±200 pA VCM Common-Mode Rejection Ratio CMRR Power-Supply Rejection Ratio PSRR Large-Signal Voltage Gain µV/°C 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 - 0.4V) (MAX4036/MAX4038 only) 44 VDD = 1.8V, VSS ≤ VCM ≤ (VDD - 0.4V) 50 VDD = 3.3V, VSS ≤ VCM ≤ (VDD - 0.2V) 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, (Note 1) MAX4039EUB MAX4039EBL-T 25 120 35 200 Reference Voltage Temperature Coefficient TCVREF Line Regulation ∆VREF/ ∆VDD Load Regulation ∆VREF/ ∆ILOAD 0 ≤ ILOAD ≤ 100µA, sourcing 0.003 -20µA ≤ ILOAD ≤ 0, sinking 0.015 Capacitive-Load Stability Range CLOAD (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 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 1.4 1.8 2.2 2.6 3.4 3.0 1.5 1.0 TA = -40°C 0 1.8 2.1 2.4 2.7 3.0 3.3 3.6 1.4 1.8 2.2 2.6 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 1 -40 3 2 -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 -30 TA = +85°C 20 10 35 TEMPERATURE (°C) -40 -50 -60 -70 10 -80 -90 VCM = 0V -15 -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 0 3.6 MAX4036 toc08 1.8 0.10 -0.20 0 0 MAX4036 toc06 0.20 OFFSET VOLTAGE (mV) 3 0.30 MAX4036 toc05 0.8 OFFSET VOLTAGE (mV) TA = +25°C MAX4036 toc04 TA = +85°C 1.0 3.4 3.0 SUPPLY VOLTAGE (V) 4 SUPPLY CURRENT (µA) 2.0 SUPPLY VOLTAGE (V) 5 INPUT BIAS CURRENT (pA) TA = +25°C 0.5 0.5 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 MAX4037 SUPPLY CURRENT vs. SUPPLY VOLTAGE AND TEMPERATURE MAX4036 toc03 MAX4036 SUPPLY CURRENT vs. SUPPLY VOLTAGE AND TEMPERATURE 0 60 85 -100 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.) VOL - VSS (mV) RL = 5kΩ 100 AV (dB) 20 15 10 RL = 100kΩ 80 10 60 5 5 RL = 100kΩ 0 RL = 100kΩ 40 0 -15 10 35 85 60 -40 -15 10 35 60 0 85 100 200 300 400 TEMPERATURE (°C) TEMPERATURE (°C) VOL (mV) AV vs. OUTPUT SWING HIGH AV vs. TEMPERATURE CROSSTALK vs. FREQUENCY RL = 5kΩ 120 120 AVOL (dB) RL = 5kΩ RL = 100kΩ 80 MAX4038/MAX4039 AV = 1V/V -20 CROSSTALK (dB) 100 100 0 RL = 100kΩ 80 60 500 MAX4036 toc15 140 MAX4036 toc13 140 MAX4036 toc14 -40 AV (dB) RL = 5kΩ 120 MAX4036 toc12 30 25 15 140 MAX4036 toc11 RL = 5kΩ 20 VDD - VOH (mV) 35 MAX4036 toc10 30 25 AV vs. OUTPUT SWING LOW OUTPUT VOLTAGE SWING LOW vs. TEMPERATURE OUTPUT VOLTAGE SWING HIGH vs. TEMPERATURE -40 RL = 5kΩ -60 RL = 100kΩ 40 -80 60 20 0 0 100 200 300 400 500 -100 -40 -15 35 60 85 0 0.1 10k 1k 100k 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 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 OP AMP SOURCE CURRENT vs. OUTPUT VOLTAGE OP AMP VOLTAGE NOISE DENSITY vs. FREQUENCY 100 VDD = 3.0V 12 NOISE (µV/√Hz) SOURCE CURRENT (mA) 14 10 8 6 MAX4036 toc20 VID = +100mV 16 1000 MAX4036 toc19 18 VDD = 1.8V 10 1 4 2 0 0.1 0.6 1.2 1.8 2.4 3.0 10 1k 100 10k FREQUENCY (Hz) OP AMP SMALL-SIGNAL TRANSIENT RESPONSE OP AMP SMALL-SIGNAL TRANSIENT RESPONSE AV = 1V/V CL = 12pF TO VSS RL = 1MΩ TO VSS 2.55V MAX4036 toc21 VOUT_ (V) AV = 1V/V CL = 250pF TO VSS RL = 1MΩ TO VSS 2.55V MAX4036 toc22 0 VIN+ VIN+ 2.45V 2.45V 2.55V 2.55V VOUT_ 2.45V VOUT_ 2.45V 40µs/div MAX4036 toc23 AV = 1V/V CL = 12pF TO VSS RL = 1MΩ TO VSS 2.5V VIN+ 1.5V AV = 1V/V CL = 12pF TO GND RL = 1MΩ TO GND VIN+ = VDD / 2 MAX4036 toc24 OP AMP TURN-ON TRANSIENT RESPONSE OP AMP LARGE-SIGNAL 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 40 30 180 2 135 -2 90 -6 45 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. LOAD CURRENT REFERENCE VOLTAGE CHANGE vs. TIME 1.234 1.02 MAX4036 toc28 1.234 MAX4036 toc27 MAX4037/MAX4039 TA = +85°C NORMALIZED VREF VREF (V) 1.230 TA = +25°C 1.01 1.233 1.232 100k FREQUENCY (Hz) REFERENCE VOLTAGE vs. TEMPERATURE 1.236 10k 1k FREQUENCY (Hz) MAX4037 1.232 MAX4039 MAX4036 toc29 20 10 0 -10 GAIN (dB) GAIN (dB) GAIN PHASE (DEGREES) MAX4036 toc25 70 60 50 MAX4036 toc26 LARGE-SIGNAL GAIN vs. FREQUENCY 80 VREF (V) TA = -40°C 1.00 0.99 1.231 1.228 0.98 1.230 1.226 -15 10 35 60 0 85 100 200 300 400 500 -100 600 REFERENCE VOLTAGE CHANGE vs. SUPPLY VOLTAGE 1.0002 100 REFERENCE LINE-TRANSIENT RESPONSE MAX4036 toc30 1.0003 0 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) TIME (HR) TEMPERATURE (°C) MAX4036 toc31 -40 NORMALIZED VREF 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 toc36 MAX4036 toc37 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 Description PIN MAX4036 MAX4037 1 3 2 2 3 MAX4038 µMAX/TDFN NAME MAX4039 FUNCTION UCSP µMAX/TDFN UCSP — — — — IN+ Noninverting Amplifier Input 4 A2 5 A2 VSS Negative Power-Supply Voltage 4 — — — — IN- Inverting Amplifier Input 4 1 — — — — OUT Amplifier Output 5 6 8 C2 10 C2 VDD Positive Power-Supply Voltage — 5 — — 6 B2 REF Reference Voltage Output — — 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) 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). 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 AV = CL INPUT VTHR 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) 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) VDD VBATT Choose the threshold voltage for VIN rising (VTHR). In this example, choose VTHR = 2.0V. Calculate R2: IN+ OUT R2 VTHR 1 1 − − R1 R 3 VREF × R1 1 = 2.0V 1 1 − − 210kΩ 10MΩ 1.2V × 210kΩ = 325kΩ VREF VIN falling: Figure 4. Battery Monitoring Selector Guide NO. OF AMPLIFIERS REFERENCE MAX4036 1 — MAX4037 1 √ MAX4038 2 — MAX4039 2 √ R1 × VDD VTHF = VTHR − R3 In this application, the MAX4036–MAX4039 supply current will vary, depending on the output state of the comparator. Power Supplies and Layout 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. 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. MAX4037 VSS PART 12 VSS REF Verify the threshold voltages with these formulas: VIN rising: 1 1 1 VTHR = VREF × R1 × + + R1 R2 R3 VBGOOD IN- 1 R2 = 6) VDD R1 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 IN+ 1 VSS 2 5 VDD MAX4036 OUT 1 6 VDD MAX4037 VSS 2 4 OUT IN- 3 5 REF 4 IN- IN+ 3 SC70 SOT23 8 VDD OUTA 1 7 OUTB INA- 2 INA+ 3 6 INB- INA+ 3 VSS 4 5 INB+ VSS 4 INA- 2 8 VDD OUTA 1 7 OUTB MAX4038 µMAX 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. (BUMP SIDE DOWN) MAX4038 MAX4039 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 (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.) 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 C ______________________________________________________________________________________ 1 1 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference 6LSOT.EPS PACKAGE OUTLINE, SOT-23, 6L 21-0058 F 1 ______________________________________________________________________________________ 1 15 MAX4036–MAX4039 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.) 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 0.014 0.010 0.007 0.005 0.120 0.116 0.0256 BSC 0.120 0.116 0.198 0.188 0.026 0.016 6∞ 0∞ 0.0207 BSC 8LUMAXD.EPS MAX4036–MAX4039 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered 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 FRONT VIEW b L SIDE VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, 8L uMAX/uSOP APPROVAL DOCUMENT CONTROL NO. 21-0036 16 ______________________________________________________________________________________ REV. J 1 1 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference 6, 8, &10L, DFN THIN.EPS D N PIN 1 INDEX AREA E E2 DETAIL A CL CL L A L e e PACKAGE OUTLINE, 6, 8, 10 & 14L, TDFN, EXPOSED PAD, 3x3x0.80 mm 21-0137 NUMBER OF LEADS SHOWN ARE FOR REFERENCE ONLY F 1 2 COMMON DIMENSIONS SYMBOL A MIN. 0.70 0.80 D 2.90 3.10 E 2.90 3.10 0.00 0.05 A1 L k MAX. 0.40 0.20 0.25 MIN. A2 0.20 REF. PACKAGE VARIATIONS PKG. CODE N D2 E2 e JEDEC SPEC b T633-1 6 1.50±0.10 2.30±0.10 0.95 BSC MO229 / WEEA 0.40±0.05 1.90 REF T833-1 8 1.50±0.10 2.30±0.10 0.65 BSC MO229 / WEEC 0.30±0.05 1.95 REF 2.00 REF [(N/2)-1] x e T1033-1 10 1.50±0.10 2.30±0.10 0.50 BSC MO229 / WEED-3 0.25±0.05 T1433-1 14 1.70±0.10 2.30±0.10 0.40 BSC ---- 0.20±0.03 2.40 REF T1433-2 14 1.70±0.10 2.30±0.10 0.40 BSC ---- 0.20±0.03 2.40 REF PACKAGE OUTLINE, 6, 8, 10 & 14L, TDFN, EXPOSED PAD, 3x3x0.80 mm 21-0137 F 2 2 ______________________________________________________________________________________ 17 MAX4036–MAX4039 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.) 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.) e 10LUMAX.EPS MAX4036–MAX4039 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference 4X S 10 10 INCHES H 0 0.50±0.1 0.6±0.1 1 1 0.6±0.1 BOTTOM VIEW TOP VIEW D2 MILLIMETERS MAX DIM MIN 0.043 A 0.006 A1 0.002 A2 0.030 0.037 0.120 D1 0.116 0.118 D2 0.114 0.120 E1 0.116 0.118 E2 0.114 0.199 H 0.187 L 0.0157 0.0275 L1 0.037 REF 0.0106 b 0.007 e 0.0197 BSC c 0.0035 0.0078 0.0196 REF S α 0° 6° MAX MIN 1.10 0.15 0.05 0.75 0.95 3.05 2.95 2.89 3.00 3.05 2.95 2.89 3.00 4.75 5.05 0.40 0.70 0.940 REF 0.177 0.270 0.500 BSC 0.090 0.200 0.498 REF 0° 6° E2 GAGE PLANE A2 c A b A1 α E1 D1 FRONT VIEW L L1 SIDE VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, 10L uMAX/uSOP APPROVAL DOCUMENT CONTROL NO. 21-0061 18 ______________________________________________________________________________________ REV. I 1 1 Low IBIAS, +1.4V/800nA, Rail-to-Rail Op Amps with +1.2V Buffered Reference PACKAGE OUTLINE, 3x3 UCSP 21-0093 I 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 19 © 2004 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. MAX4036–MAX4039 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.)