19-1445; Rev 0; 4/99 Micropower, Single-Supply, Rail-to-Rail Precision Differential Amplifiers Rail-to-Rail® The MAX4198/MAX4199 low-power, differential amplifiers are ideal for single-supply applications that benefit from a low 0.01% gain error. The MAX4198 is factory trimmed to a fixed gain of +1V/V, and the MAX4199 is trimmed to a fixed gain of +10V/V. Capable of operating from a single +2.7V to +7.5V supply or from dual ±1.35V to ±3.75V supplies, they consume only 42µA while achieving -3dB bandwidths of 175kHz (MAX4198) and 45kHz (MAX4199). These amplifiers feature a shutdown mode that reduces the supply current to 6.5µA. The MAX4198/MAX4199 can drive 5kΩ loads to within 100mV from each rail. The standard differential amplifier configurations provide common-mode rejection of 90dB for the MAX4198 and 110dB for the MAX4199. The input common-mode voltage range for the MAX4198 extends 100mV Beyond-the-Rails™. The MAX4198/MAX4199 are offered in a space-saving 8-pin µMAX package. For complete micropower, rail-torail instrumentation amplifiers, see the MAX4194– MAX4197 data sheet. Applications Instrumentation Amplifier Building Block Features ♦ Low 0.01% Gain Error ♦ High Common-Mode Rejection: 110dB (MAX4199) ♦ 10µV Input Offset Voltage (MAX4199) 30µV Input Offset Voltage (MAX4198) ♦ +2.7V to +7.5V Single-Supply Operation ♦ 42µA Supply Current ♦ 175kHz (MAX4198) and 45kHz (MAX4199) -3dB Bandwidth ♦ 6.5µA Shutdown Current ♦ Rail-to-Rail Outputs Drive 5kΩ Loads ♦ Input Voltage Range Extends 100mV Beyond-theRails (MAX4198) ♦ Available in Space-Saving 8-Pin µMAX Package Ordering Information PART TEMP. RANGE PINPACKAGE MAX4198EUA -40°C to +85°C 8 µMAX GAIN (V/V) 1 Differential Voltage Amplifiers MAX4198ESA -40°C to +85°C 8 SO 1 Data-Acquisition Systems MAX4199EUA -40°C to +85°C 8 µMAX 10 Portable/Battery-Powered Equipment MAX4199ESA -40°C to +85°C 8 SO 10 Transducer Interface Current-Sense Amplifiers Pin Configuration Functional Diagram TOP VIEW 7 VCC 5 FB IN- 2 25k 6 OUT MAX4198 MAX4199 IN+ 25k (250k) REF 1 IN- 2 IN+ 25k 3 25k (250k) 1 REF 4 VEE ( ) ARE FOR MAX4199 ONLY. 3 MAX4198 MAX4199 VEE 4 8 SHDN 7 VCC 6 OUT 5 FB µMAX/SO Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd. Beyond-the-Rails is a trademark of Maxim Integrated Products. ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 408-737-7600 ext. 3468. MAX4198/MAX4199 General Description MAX4198/MAX4199 Micropower, Single-Supply, Rail-to-Rail Precision Differential Amplifiers ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC to VEE)..................................................+8V All Other Pins to GND ......................(VEE - 0.3V) to (VCC + 0.3V) Output Short Circuit Duration (to VCC or VEE)............Continuous Continuous Power Dissipation (TA = +70°C) SO (derate 9.09mW/°C above +70°C) ..........................471mW µMAX (derate 4.1mW/°C above +70°C) .......................330mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range ............................ -65°C to +150°C Lead Temperature (soldering, 10sec) .............................+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—MAX4198 (+5V Supply) (VCC = +5V, VEE = 0V, RL = 25kΩ tied to VCC / 2, VREF = VCC / 2, V SHDN = VCC - 1.5V, typical values are at T A = +25°C, TA = TMIN to TMAX, unless otherwise noted.) (Note 1) PARAMETER Supply Voltage Range (Note 2) SYMBOL VCC Input Offset Voltage VOS Input Offset Voltage Drift TCO Input Resistance RIN Input Voltage Range VIN DC Common-Mode Rejection CMRDC AC Common-Mode Rejection CMRAC Power-Supply Rejection Input Noise Voltage PSR CONDITIONS Single supply Dual supply TA = +25°C, VCM = VCC / 2 TA = TMIN to TMAX, VCM = VCC / 2 Nonlinearity 2 ±3.75 ±500 ±1000 ±750 ±2300 ±5 ±20 ±30 ±100 IN- differential-mode 25 Common-mode 50 VCM = VEE - 0.1V to VCC + 0.1V 90 MAX4198EUA 70 90 Sink/source VEE + 0.1V ≤ VOUT ≤ VCC 0.1V RL = 25kΩ, VEE + 0.1V ≤ VOUT ≤ VCC - 0.1V RL = 5kΩ, VEE + 0.2V ≤ VOUT ≤ VCC - 0.2V 90 UNITS V µV µV/°C kΩ VCC + 0.1 74 VCM = VEE - 0.1 to VCC + 0.1V, f = 60Hz, f = 120Hz +2.7V ≤ VCC ≤ +7.5V, VCM = +1.5V, VREF = +1.5V, RL = 25kΩ to +1.5V f = 10Hz f = 100Hz f = 10kHz f = 0.1Hz to 10Hz VCM = VCC / 2, TA = +25°C VEE - 0.1 MAX4198ESA RL = 5kΩ, ±10mV input overdrive Gain Temperature Coefficient ±1.35 ±0.5 ±1 50 Guaranteed by CMR test MAX 7.5 MAX4198ESA MAX4198EUA IN+ differential-mode RL = 25kΩ, ±10mV input overdrive Gain Error TYP 2.7 MAX4198ESA MAX4198EUA MAX4198ESA MAX4198EUA Output Voltage Swing Short-Circuit Current MIN V dB 90 dB 115 dB 120 60 58 7.8 VEE + 0.1 VEE + 0.03 to to VCC - 0.1 VCC - 0.03 VEE + 0.2 VEE + 0.1 to to VCC - 0.2 VCC - 0.1 ±5.5 nV√Hz µVRMS V mA ±0.01 ±0.1 ±0.01 ±0.1 MAX4198ESA ±0.2 ±3 MAX4198EUA ±0.65 ±6 % ppm/°C VEE + 0.1V ≤ VOUT ≤ VCC - 0.1V ±0.0003 _______________________________________________________________________________________ % Micropower, Single-Supply, Rail-to-Rail Precision Differential Amplifiers (VCC = +5V, VEE = 0V, RL = 25kΩ tied to VCC / 2, VREF = VCC / 2, V SHDN = VCC - 1.5V, typical values are at T A = +25°C, TA = TMIN to TMAX, unless otherwise noted.) (Note 1) PARAMETER Capacitive Load Stability -3dB Bandwidth SYMBOL CONDITIONS MIN TYP CL BW-3dB MAX UNITS 690 pF VOUT ≤ 0.1Vp-p, VCM = VCC / 2 175 kHz Slew Rate SR VOUT = 2Vp-p step 0.07 V/µs Settling Time to 0.1% ts VOUT = 2Vp-p step 34 µs 0.001 % Total Harmonic Distortion Supply Current Shutdown Supply Current THD VOUT = 2Vp-p, f = 1kHz ICC VCM = VCC / 2, VIN+ = VIN- 45 55 µA V SHDN = VIL 6.5 12 µA ISHDN Input Logic Voltage High (Note 3) VIH Input Logic Voltage Low (Note 3) VIL VCC - 1.5 V VCC - 2.5 V SHDN Input Bias Current V SHDN = VCC - 1.5V or V SHDN = VEE Enable/Disable Settling Time V SHDN = VCC - 2.5V to VCC - 1.5V, VOUT = 3.5V, settled to within 0.1% 28 µs VOUT = 3.5V, settled to within 0.1% 800 µs tON/OFF Power-Up Delay -0.1 0.1 µA ELECTRICAL CHARACTERISTICS—MAX4198 (+3V Supply) (VCC = +3V, VEE = 0V, RL = 25kΩ tied to VCC / 2, VREF = VCC / 2, V SHDN = VCC - 1.5V, typical values are at TA = +25°C, TA = TMIN to TMAX, unless otherwise noted.) (Note 1) PARAMETER SYMBOL Input Offset Voltage VOS Input Offset Voltage Drift TCO Input Voltage Range VIN DC Common-Mode Rejection CMRDC CONDITIONS TYP MAX MAX4198ESA MAX4198EUA MAX4198ESA MAX4198EUA ±35 ±100 MAX4198ESA MAX4198EUA Guaranteed by CMR test MAX4198ESA VCM = VEE - 0.1 to VCC + 0.1 MAX4198EUA ±0.5 ±1.0 ±600 ±1100 ±850 ±2400 ±5.0 ±20 VCC + 0.1 TA = +25°C, VCM = VCC / 2 TA = TMIN to TMAX, VCM = VCC / 2 RL = 25kΩ, ±10mV input overdrive Output Voltage Swing RL = 5kΩ, ±10mV input overdrive Short-Circuit Current Sink/source Gain Error RL = 25kΩ, VEE + 0.1V ≤ VCM = VCC / 2, VOUT ≤ VCC - 0.1V TA = +25°C RL = 5kΩ, VEE + 0.2V ≤ VOUT ≤ VCC - 0.2V VEE + 0.1V ≤ VOUT ≤ VCC 0.1V Gain Temperature Coefficient Supply Current ICC Shutdown Supply Current MIN VEE - 0.1 74 90 70 90 VEE + 0.1 VEE + 0.03 to to VCC - 0.1 VCC - 0.03 VEE + 0.2 VEE + 0.1 to to VCC - 0.2 VCC - 0.1 ±4.5 ±0.01 ±0.1 ±0.01 ±0.1 MAX4198ESA ±0.2 ±3 MAX4198EUA ±0.65 ±6 VIH Input Logic Low Voltage (Note 3) VIL µV µV/°C V dB V mA % ppm/°C VCM = VCC / 2, VDIFF = 0 I SHDN Input Logic High Voltage (Note 3) UNITS 42 µA 6.5 µA VCC - 1.5 V VCC - 2.5 V _______________________________________________________________________________________ 3 MAX4198/MAX4199 ELECTRICAL CHARACTERISTICS—MAX4198 (+5V Supply) (continued) MAX4198/MAX4199 Micropower, Single-Supply, Rail-to-Rail Precision Differential Amplifiers ELECTRICAL CHARACTERISTICS—MAX4199 (+5V Supply) (VCC = +5V, VEE = 0V, RL = 25kΩ tied to VCC / 2, VREF = VCC / 2, V S HDN = VCC - 1.5V, typical values are at TA = +25°C, TA = TMIN to TMAX, unless otherwise noted.) (Note 1) PARAMETER Supply Voltage Range (Note 2) SYMBOL VCC Input Offset Voltage VOS Input Offset Voltage Drift TCO Input Resistance RIN CONDITIONS Single supply Dual supply TA = +25°C, VCM = VCC / 2 TA = TMIN to TMAX, VCM = VCC / 2 MAX4199EUA MAX4199ESA MAX4199EUA MAX4199ESA MAX4199EUA 25 Common-mode 275 CMRDC VCM = VEE - 0.1V to VCC - 1.0V AC Common-Mode Rejection CMRAC VCM = VEE - 0.1V to VCC - 1.0V, f = 60Hz Guaranteed by CMR test 84 110 80 110 RL = 25kΩ, ±10mV input overdrive Output Voltage Swing RL = 5kΩ, ±10mV input overdrive Short-Circuit Current Sink/source Gain Error RL = 25kΩ, VEE + 0.1V ≤ VCM = VCC / 2, VOUT ≤ VCC - 0.1V TA = +25°C RL = 5kΩ, VEE + 0.2V ≤ VOUT ≤ VCC - 0.2V Capacitive Load Stability -3dB Bandwidth µV µV/°C V 110 dB 120 dB 60 40 38 6.6 VEE + 0.1 VEE + 0.02 to to VCC - 0.1 VCC - 0.02 VEE + 0.2 VEE + 0.1 to to VCC - 0.2 VCC - 0.1 nV√Hz µVRMS V mA ±0.01 ±0.3 ±0.01 ±0.3 MAX4199ESA ±1 ±5 MAX4199EUA ±2 ±10 % ppm/°C CL BW-3dB V dB ±5.5 VEE + 0.1V ≤ VOUT ≤ VCC - 0.1V Nonlinearity 90 UNITS kΩ VCC - 1.0 MAX4199EUA +2.7V ≤ VCC ≤ +7.5V, VCM = +1.5V, VREF = +1.5V, RL = 25kΩ to +1.5V VEE + 0.1V ≤ VOUT ≤ VCC 0.1V VEE - 0.1 MAX4199ESA f = 10Hz f = 100Hz f = 10kHz f = 0.1Hz to 10Hz Gain Temperature Coefficient 7.5 ±3.75 ±300 ±600 ±500 ±1475 ±3 ±15 ±10 ±100 IN- differential mode DC Common-Mode Rejection Input Noise Voltage MAX ±0.25 ±0.75 275 VIN PSR TYP 2.7 ±1.35 MAX4199ESA MAX4199EUA IN+ differential mode Input Voltage Range (Note 2) Power-Supply Rejection MIN ±0.0003 % 600 pF VOUT ≤ 0.1Vp-p, VCM = VCC / 2 45 kHz Slew Rate SR VOUT = 2Vp-p 0.1 V/µs Settling Time to 0.1% ts VOUT = 2Vp-p step 37 µs 0.001 % Total Harmonic Distortion Supply Current Shutdown Supply Current 4 THD VOUT = 2Vp-p, f = 1kHz ICC VCM = VCC / 2, VIN+ = VIN- 45 55 µA V SHDN = VIL 6.5 12 µA I SHDN _______________________________________________________________________________________ Micropower, Single-Supply, Rail-to-Rail Precision Differential Amplifiers (VCC = +5V, VEE = 0V, RL = 25kΩ tied to VCC / 2, VREF = VCC / 2, V S HDN = VCC - 1.5V, typical values are at TA = +25°C, TA = TMIN to TMAX, unless otherwise noted.) (Note 1) PARAMETER SYMBOL Input Logic Voltage High (Note 3) VIH Input Logic Voltage Low (Note 3) VIL CONDITIONS MIN TYP MAX UNITS VCC - 1.5 V VCC - 2.5 V SHDN Input Bias Current V SHDN = VCC - 1.5V or V SHDN = VEE Enable/Disable Settling Time V SHDN = VCC - 2.5V to VCC - 1.5V, VOUT = 3.5V, settled to within 0.1% 35 µs VOUT = 3.5V, settled to within 0.1% 800 µs tON/OFF Power-Up Delay -0.1 0.1 µA ELECTRICAL CHARACTERISTICS—MAX4199 (+3V Supply) (V CC = +3V, V EE = 0V, R L = 25kΩ tied to V CC / 2, V REF = V CC / 2, V S HDN = V CC - 1.5V, values are at T A = +25°C, TA = TMIN to TMAX, unless otherwise noted.) (Note 1) PARAMETER SYMBOL Input Offset Voltage VOS Input Offset Voltage Drift TCO Input Voltage Range VIN DC Common-Mode Rejection CMRDC CONDITIONS TA = +25°C, VCM = VCC / 2 TA = TMIN to TMAX, VCM = VCC / 2 MAX4199ESA MAX4199EUA MAX4199ESA MAX4199EUA MAX4199ESA MAX4199EUA Guaranteed by CMR test VCM = VEE - 0.1 to VCC - 1.1 ±0.25 ±0.75 VEE - 0.1 110 110 Sink/source Gain Error RL = 25kΩ, VEE + 0.1V ≤ VCM = VCC / 2, VOUT ≤ VCC - 0.1V TA = +25°C RL = 5kΩ, VEE + 0.2V ≤ VOUT ≤ VCC - 0.2V ICC VIH Input Logic Low Voltage (Note 3) VIL UNITS µV µV/°C V dB VEE + 0.1 VEE + 0.02 to to VCC - 0.1 VCC - 0.02 VEE + 0.2 VEE + 0.1 to to VCC - 0.2 VCC - 0.1 ±4.5 V mA ±0.01 ±0.3 ±0.01 ±0.3 MAX4199ESA ±1 ±5 MAX4199EUA ±2 ±10 % ppm/°C VCM = VCC / 2, VDIFF = 0 I SHDN Input Logic High Voltage (Note 3) ±400 ±700 ±600 ±1675 ±5 ±15 VCC - 1.1 80 Short-Circuit Current Shutdown Supply Current ±15 ±100 84 RL = 5kΩ, ±10mV input overdrive Supply Current MAX MAX4199EUA Output Voltage Swing VEE + 0.1V ≤ VOUT ≤ VCC 0.1V TYP MAX4199ESA RL = 25kΩ, ±10mV input overdrive Gain Temperature Coefficient MIN 42 µA 6.5 µA VCC - 1.5 V VCC - 2.5 V Note 1: The MAX4198EUA and the MAX4199EUA are 100% production tested at +25°C. All temperature limits are guaranteed by design. Note 2: Guaranteed by PSR test. Note 3: When shutdown input is at logic high, the part is active; when at logic low, the part is in shutdown. _______________________________________________________________________________________ 5 MAX4198/MAX4199 ELECTRICAL CHARACTERISTICS—MAX4199 (+5V Supply) (continued) Typical Operating Characteristics (VCC = +5V, VEE = 0V, RL = 25kΩ to VCC / 2, V SHDN = VCC - 1.5V, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.) MAX4198 SMALL-SIGNAL GAIN vs. FREQUENCY 2 MAX4198 42 3 2 1 0 GAIN (dB) MAX4199 41 40 39 -1 -2 0 -1 -2 -3 -3 37 -4 -4 36 -5 -5 35 -6 -15 10 35 TEMPERATURE (°C) 60 -6 0.1k 85 POWER-SUPPLY REJECTION vs. FREQUENCY 10k 100k FREQUENCY (Hz) 1M 0.1k 0 -20 600 -80 -110 -100 VOLTAGE (mV) CMR (dB) -90 MAX4198 100 1k 10k 100k 10 100 1k 10k 100k FREQUENCY (Hz) COMMON-MODE REJECTION vs. TEMPERATURE INPUT OFFSET VOLTAGE vs. TEMPERATURE -80 MAX4198 -90 -100 MAX4199 MAX4199 VOH - VCC MAX4198 0.1 1M 1 10 100 LOAD (kΩ) GAIN ERROR vs. TEMPERATURE 0.008 MAX4198toc08 100 INPUT OFFSET VOLTAGE (µV) MAX4198toc07 -70 0 -200 -1000 FREQUENCY (Hz) -60 200 -800 MAX4199 0.006 0.004 0.002 50 GAIN ERROR (%) 10 VOL - VEE MAX4198 -600 -120 1 1M -400 MAX4199 -130 MAX4199 800 400 -60 100k 1000 -40 -70 10k OUTPUT VOLTAGE HIGH AND LOW vs. LOAD RESISTANCE MAX4198 -50 1k FREQUENCY (Hz) MAX4198toc05 -30 1k COMMON-MODE REJECTION vs. FREQUENCY MAX4198toc04 -10 PSR (dB) 1 38 -40 MAX4198toc03 3 MAX4199 0 MAX4198 MAX4198toc09 SUPPLY CURRENT (µA) 43 NORMALIZED GAIN (dB) 44 MAX4198toc06 MAX4198toc01 45 MAX4199 SMALL-SIGNAL GAIN vs. FREQUENCY MAX4198toc02 SUPPLY CURRENT vs. TEMPERATURE CMR (dB) MAX4198/MAX4199 Micropower, Single-Supply, Rail-to-Rail Precision Differential Amplifiers 0 -0.002 MAX4199 -0.004 -0.006 -0.008 -50 MAX4198 -0.010 -110 -0.012 -40 6 -0.014 -100 -120 -15 10 35 TEMPERATURE (°C) 60 85 -40 -15 10 35 TEMPERATURE (°C) 60 85 -40 -15 10 35 TEMPERATURE (°C) _______________________________________________________________________________________ 60 85 Micropower, Single-Supply, Rail-to-Rail Precision Differential Amplifiers VOLTAGE NOISE DENSITY vs. FREQUENCY TOTAL HARMONIC DISTORTION VOLTAGE NOISE vs. FREQUENCY THD + VOLTAGE NOISE (%) 1k MAX4198 100 SMALL-SIGNAL PULSE RESPONSE MAX4198toc12 MAX4198toc11 1.000 MAX4198toc10 VOLTAGE NOISE DENSITY (nV/√Hz) 10k INPUT 50mV/div 0.100 0.010 MAX4199 OUTPUT 50mV/div 0.001 MAX4198 MAX4199 10 1 10 100 1k 10k 100k 0 100 1k 50µs/div 10k FREQUENCY (Hz) FREQUENCY (Hz) MAX4199 SMALL-SIGNAL PULSE RESPONSE MAX4199 LARGE-SIGNAL PULSE RESPONSE MAX4198 LARGE-SIGNAL PULSE RESPONSE MAX4198toc13 MAX4198toc15 MAX4198toc14 INPUT 5mV/div INPUT 500mV/div INPUT 50mV/div OUTPUT 50mV/div OUTPUT 500mV/div OUTPUT 500mV/div 50µs/div 50µs/div 50µs/div MAX4198 SMALL-SIGNAL PULSE RESPONSE WITH CAPACITIVE LOAD MAX4198 SMALL-SIGNAL PULSE RESPONSE WITH EXCESSIVE CAPACITIVE LOAD MAX4198 SMALL-SIGNAL PULSE RESPONSE WITH EXCESSIVE CAPACITIVE LOAD AND ISOLATION RESISTOR MAX4198toc16 MAX4198toc18 MAX4198toc17 CL = 690pF CL = 1060pF RISO = 50Ω CL = 1060pF RISO = 0Ω OUTPUT 50mV/div OUTPUT 50mV/div OUTPUT 50mV/div 50µs/div INPUT 50mV/div INPUT 50mV/div INPUT 50mV/div 50µs/div 50µs/div _______________________________________________________________________________________ 7 MAX4198/MAX4199 Typical Operating Characteristics (continued) (VCC = +5V, VEE = 0V, RL = 25kΩ to VCC / 2, V SHDN = VCC - 1.5V, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VCC = +5V, VEE = 0V, RL = 25kΩ to VCC / 2, V SHDN = VCC - 1.5V, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.) MAX4199 SMALL-SIGNAL PULSE RESPONSE WITH CAPACITIVE LOAD MAX4199 SMALL-SIGNAL PULSE RESPONSE WITH EXCESSIVE CAPACITIVE LOAD AND ISOLATION RESISTOR MAX4199 SMALL-SIGNAL PULSE RESPONSE WITH EXCESSIVE CAPACITIVE LOAD MAX4198toc19 MAX4198toc20 MAX4198toc21 INPUT 5mV/div INPUT 5mV/div CL = 590pF INPUT 5mV/div CL = 760pF RISO = 75Ω CL = 760pF RISO = 0Ω OUTPUT 50mV/div OUTPUT 50mV/div OUTPUT 50mV/div 50µs/div MAX4198 TIME EXITING SHUTDOWN 50µs/div MAX4198 HISTOGRAM (VOS BASED ON 200 UNITS) MAX4199 TIME EXITING SHUTDOWN MAX4198toc22 MAX4198toc23 60 50 INPUT (SHDN PIN) 500mV/div 40 COUNT INPUT (SHDN PIN) 500mV/div OUTPUT 500mV/div MAX4198toc24 50µs/div OUTPUT 500mV/div 30 20 10 0 10µs/div -300 -240 -180 -120 -60 10µs/div 0 60 120 180 240 300 VOS (µV) 100 90 80 140 120 70 60 100 60 COUNT COUNT 80 50 40 40 80 60 30 40 20 20 20 10 0 0 0 -300 -240 -180 -120 -60 0 60 120 180 240 300 VOS (µV) 8 160 MAX4198toc26 100 MAX4198toc25 120 MAX4199 HISTOGRAM (GAIN ACCURACY BASED ON 280 UNITS) MAX4198 HISTOGRAM (GAIN ACCURACY BASED ON 200 UNITS) MAX4198toc27 MAX4199 HISTOGRAM (VOS BASED ON 280 UNITS) COUNT MAX4198/MAX4199 Micropower, Single-Supply, Rail-to-Rail Precision Differential Amplifiers -0.08 -0.06 -0.04 -0.02 0 0.02 0.04 0.06 0.08 GAIN ERROR (%) -0.24 -0.18 -0.12 -0.06 0 -0.06 0.12 0.18 0.24 GAIN ERROR (%) _______________________________________________________________________________________ Micropower, Single-Supply, Rail-to-Rail Precision Differential Amplifiers MAX4198 INPUT COMMON-MODE RANGE vs. SUPPLY VOLTAGE INPUT COMMON-MODE VOLTAGE (V) VREF = VCC/2 6.5 5.5 4.5 3.5 2.5 1.5 0.5 8.5 INPUT COMMON-MODE VOLTAGE (V) MAX4198toc28 7.5 MAX4198toc29 MAX4199 INPUT COMMON-MODE RANGE vs. SUPPLY VOLTAGE VREF = VCC/2 7.5 6.5 5.5 4.5 3.5 2.5 1.5 0.5 -0.5 -0.5 2 3 4 5 6 7 2 8 SUPPLY VOLTAGE (V) 3 4 5 6 7 8 SUPPLY VOLTAGE (V) Pin Description PIN NAME FUNCTION 1 REF Reference Voltage Input. Offsets output voltage. 2 IN- Inverting Input 3 IN+ Noninverting Input 4 VEE Negative Supply Voltage 5 FB Feedback Resistor. Can be used as a sense input. 6 OUT Amplifier Output 7 VCC Positive Supply Voltage 8 SHDN Shutdown Control. Shutdown threshold is referenced to VCC. When pulled 2.5V below VCC, part is in shutdown. _______________Detailed Description The MAX4198/MAX4199 are precision low-power differential amplifiers with factory-trimmed internal gain-setting resistors. The MAX4198 is trimmed to a gain of +1V/V and the MAX4199 is trimmed to a gain of +10V/V. Input Stage The Functional Diagram shows the internal structure of the MAX4198/MAX4199. Although the resistors are precision matched, their absolute value varies by ±25%. The typical input impedance for the MAX4198 is 50kΩ for the noninverting input and 25kΩ for the inverting input. The typical input impedance for the MAX4199 is 275kΩ for the noninverting input and 25kΩ for the inverting input. The common-mode inputs of the internal op amp can range from VEE to (VCC - 1.1V). Although the inputs to the internal op amp are not rail-to-rail, the internal resistors form a voltage divider that extends the input common-mode range beyond-the-rails for the MAX4198. The overall input range of the MAX4198 extends 100mV beyond-the-rails without adversely affecting commonmode rejection or undergoing phase reversal (VCC = 5V). The MAX4199 input common-mode range extends from 100mV below the negative rail to (VCC - 1V) (see the Input Common-Mode Voltage Range vs. Supply Voltage graph in the Typical Operating Characteristics). _______________________________________________________________________________________ 9 MAX4198/MAX4199 Typical Operating Characteristics (continued) (VCC = +5V, VEE = 0V, RL = 25kΩ to VCC / 2, V SHDN = VCC - 1.5V, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.) MAX4198/MAX4199 Micropower, Single-Supply, Rail-to-Rail Precision Differential Amplifiers Rail-to-Rail Output Stage The MAX4198/MAX4199 output stage incorporates a common-source rail-to-rail structure which maximizes the dynamic range of the differential amplifier. The output can swing to within 100mV from each rail with a 5kΩ load to VCC / 2 (see Typical Operating Characteristics). IN- FB VCC Shutdown Mode The MAX4198/MAX4199 have an active-low shutdown input. SHDN input logic thresholds are referenced to VCC, not to GND. Pulling SHDN 2.5V below the positive rail places the amplifiers in a 12µA (max) shutdown mode. The MAX4198/MAX4199 exit or enter shutdown in 35µs. In shutdown, the OUT pin is high-impedance. RISO OUT MAX4198 MAX4199 OUTPUT RL CL VEE INPUT IN+ REF Applications Information Driving Capacitive Loads The MAX4198/MAX4199 are relatively immune to oscillations caused when driving large capacitive loads. Although heavy load capacitance increases transient ringing, sustained oscillations typically don’t occur for loads under 600pF (see Pulse Response with Capacitive Load in the Typical Operating Characteristics). Applications that require driving higher capacitive loads can isolate the output capacitance using a 15Ω to 100Ω resistor between the amplifier output and the load (Figure 1). Although adding an isolation resistor dampens the response enough to prevent oscillations, it does so at the expense of bandwidth and DC accuracy. Figure 1. Dual-Supply, Capacitive-Load Driving Circuit VA IN- FB VCC OUT MAX4198 MAX4199 VOUT = (VB - VA) (MAX4198) VOUT = 10 (VB - VA) (MAX4199) VEE VB IN+ Power Supply Considerations The MAX4198/MAX4199 operate from single +2.7V to +7.5V supplies or from dual ±1.35V to ±3.75V supplies, and they consume only 45µA of supply current. Excellent power-supply rejection permits the amplifiers to be operated directly from a decaying 3V cell without excessive error. To maximize AC performance, the supply must be bypassed with a 0.1µF ceramic capacitor to ground that must be as close as possible to the pin. If dual supplies are used, bypass both supply pins with 0.1µF to ground. VOUT REF Figure 2. Standard Difference Amplifier VA IN- FB VCC Application Circuits Differential amplifiers can be used in single-ended and other amplifier applications. Figures 2 through 6 show the MAX4198/MAX4199 in different configurations. The internally trimmed and matched resistors offer convenience and have a distinct advantage over external resistors. These amplifiers are not compensated for single-ended unity gain; therefore, IN- should not be connected to OUT or left unconnected. OUT MAX4198 MAX4199 VOUT = -VA (MAX4198) VEE VOUT = -10VA (MAX4199) IN+ REF Figure 3. Precision Inverting Buffer 10 VOUT ______________________________________________________________________________________ Micropower, Single-Supply, Rail-to-Rail Precision Differential Amplifiers also be used as an instrumentation amplifier building block. The circuit of Figure 7 takes advantage of the 10pA (max), 0.1pA (typ) bias current of the MAX406A to form an instrumentation amplifier similar to the MAX4194 family, except with lower input bias currents. The MAX406A's low 1.2µA supply current maintains a low overall supply current. VCC IN+ IN- 2 5 FB FB VCC VCC 6 IN+ VA VOUT INOUT VOUT 3 VEE REF OUT VA VOUT = 2VA VOUT = -VA 1 MAX4198 MAX4198 REF Figure 4. Precision Gain of Two Amplifiers Figure 5. Single-Supply Inverting Amplifier Biased at VCC / 2 VA A1 VA 2 IN- FB 5 IN- VCC 6 OUT MAX4544 6 NO 5 3 COM IN+ 4 NC FB R2 R1 VOUT OUT VOUT R2 VEE 1 REF IN 1 MAX4198 LOGIC VOUT IN -VA 0 +VA 1 IN+ A2 VB NOTE: MAX4544 PINOUT FOR 6-PIN SOT23-6 Figure 6. Digitally Controlled Precision Gain of ±1 Amplifier A1, A2 = MAX406A REF MAX4198 VOUT = (1 + 2R2 / R1) (VB - VA) Figure 7. Ultra-Low Input Bias Current (0.1pA) Instrumentation Amplifiers with 47µA Supply-Current Consumption ______________________________________________________________________________________ 11 MAX4198/MAX4199 Instrumentation Amplifier Applications For applications that require a complete low-power instrumentation amplifier, refer to the MAX4194– MAX4197 data sheet. Some differential to single-ended voltage amplifier applications that don’t require a high input impedance can use the MAX4198/MAX4199 for gains of +1V/V or +10V/V. The MAX4198/MAX4199 can Chip Information TRANSISTOR COUNT: 250 SUBSTRATE CONNECTED TO VEE Package Information 8LUMAXD.EPS MAX4198/MAX4199 Micropower, Single-Supply, Rail-to-Rail Precision Differential Amplifiers Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 1999 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.