View MAX4040_29722.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

19-1377; Rev 0; 5/98
Single/Dual/Quad, Low-Cost, SOT23, Micropower Rail-to-Rail I/O Op Amps
________________General Description
The MAX4040-MAX4044 family of micropower op amps operates from a single +2.4V to +5.5V supply or dual 1.2V to 2.75V supplies and have Rail-to-Rail(R) input and output capabilities. These amplifiers provide a 90kHz gain-bandwidth product while using only 10A of supply current per amplifier. The MAX4041/MAX4043 have a low-power shutdown mode that reduces supply current to less than 1A and forces the output into a high-impedance state. The combination of low-voltage operation, rail-to-rail inputs and outputs, and ultra-low power consumption makes these devices ideal for any portable/battery-powered system. These amplifiers have outputs that typically swing to within 10mV of the rails with a 100k load. Rail-to-rail input and output characteristics allow the full powersupply voltage to be used for signal range. The combination of low input offset voltage, low input bias current, and high open-loop gain makes them suitable for lowpower/low-voltage precision applications. The MAX4040 is offered in a space-saving 5-pin SOT23 package. All specifications are guaranteed over the -40C to +85C extended temperature range.
____________________________Features
o Single-Supply Operation Down to +2.4V o Ultra-Low Power Consumption: 10A Supply Current per Amplifier 1A Shutdown Mode (MAX4041/MAX4043) o Rail-to-Rail Input Common-Mode Range o Outputs Swing Rail-to-Rail o No Phase Reversal for Overdriven Inputs o 200V Input Offset Voltage o Unity-Gain Stable for Capacitive Loads up to 200pF o 90kHz Gain-Bandwidth Product o Available in Space-Saving 5-Pin SOT23 and 8-Pin MAX Packages
MAX4040-MAX4044
Ordering Information
PART MAX4040EUK-T TEMP. RANGE -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C PINSOT PACKAGE TOP MARK 5 SOT23-5 8 MAX 8 SO 8 SO 8 MAX 8 MAX 8 SO 10 MAX 14 SO 14 SO ACGF -- -- -- -- -- -- -- -- --
________________________Applications
Battery-Powered Systems Portable/Battery-Powered Electronic Equipment Digital Scales Strain Gauges Sensor Amplifiers Cellular Phones Notebook Computers PDAs
MAX4040EUA MAX4040ESA MAX4041ESA MAX4041EUA MAX4042EUA MAX4042ESA MAX4043EUB MAX4043ESD MAX4044ESD
Selector Guide
PART MAX4040 MAX4041 MAX4042 MAX4043 MAX4044 NO. OF AMPS 1 1 2 2 4 SHUTDOWN -- Yes -- Yes -- PIN-PACKAGE 5-pin SOT23, 8-pin MAX/SO 8-pin MAX/SO 8-pin MAX/SO 10-pin MAX/ 14-pin SO 14-pin SO
VEE 2
Pin Configurations
TOP VIEW
OUT 1 5 VCC
MAX4040
IN+ 3
4
IN-
Rail-to-Rail is a registered trademark of Nippon Motorola Ltd.
SOT23-5 Pin Configurations continued at end of data sheet.
________________________________________________________________ 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.
Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps MAX4040-MAX4044
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (VCC to VEE)..................................................+6V All Other Pins ...................................(VCC + 0.3V) to (VEE - 0.3V) Output Short-Circuit Duration to VCC or VEE ..............Continuous Continuous Power Dissipation (TA = +70C) 5-Pin SOT23 (derate 7.1mW/C above +70C).............571mW 8-Pin MAX (derate 4.1mW/C above +70C) ..............330mW 8-Pin SO (derate 5.88mW/C above +70C).................471mW 10-Pin MAX (derate 5.6mW/C above +70C) ...........444mW 14-Pin SO (derate 8.33mW/C above +70C)..............667mW Operating Temperature Range ...........................-40C to +85C Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +160C Lead Temperature (soldering, 10sec) .............................+300C
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--TA = +25C
(VCC = +5.0V, VEE = 0, VCM = 0, VOUT = VCC / 2, SHDN = VCC, RL = 100k tied to VCC / 2, unless otherwise noted.) PARAMETER Supply-Voltage Range Supply Current per Amplifier Shutdown Supply Current per Amplifier Input Offset Voltage Input Bias Current Input Offset Current Differential Input Resistance Input Common-Mode Voltage Range Common-Mode Rejection Ratio Power-Supply Rejection Ratio Large-Signal Voltage Gain Output Voltage Swing High Output Voltage Swing Low Output Short-Circuit Current Channel-to-Channel Isolation SYMBOL VCC ICC ICC(SHDN) VCC = 2.4V VCC = 5.0V SHDN = VEE, MAX4041 and MAX4043 only VEE VCM VCC VEE VCM VCC VEE VCM VCC VIN+ - VIN- < 1.0V VIN+ - VIN- > 2.5V Inferred from the CMRR test VEE VCM VCC 2.4V VCC 5.5V (VEE + 0.2V) VOUT (VCC - 0.2V) Specified as VCC - VOH Specified as VEE - VOL Sourcing Sinking Specified at DC, MAX4042/MAX4043/MAX4044 only RL = 100k RL = 25k RL = 100k RL = 25k RL = 100k RL = 25k 74 MAX404_EU_ All other packages VEE 65 70 75 94 94 85 94 85 10 60 10 40 0.7 2.5 80 60 90 VCC = 2.4V VCC = 5.0V MAX4044ESD VOS IB IOS RIN(DIFF) VCM CMRR PSRR AVOL VOH VOL IOUT(SC) MAX404_EU_ All other packages CONDITIONS Inferred from PSRR test MIN 2.4 10 14 1.0 2.0 0.20 0.25 0.20 2 0.5 45 4.4 VCC 5.0 2.0 2.5 1.50 10 3.0 20 TYP MAX 5.5 UNITS V A A mV mV nA nA M k V dB dB dB mV mV mA dB
2
_______________________________________________________________________________________
Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps
ELECTRICAL CHARACTERISTICS--TA = +25C (continued)
(VCC = +5.0V, VEE = 0, VCM = 0, VOUT = VCC / 2, SHDN = VCC, RL = 100k tied to VCC / 2, unless otherwise noted.) PARAMETER Output Leakage Current in Shutdown SHDN Logic Low SHDN Logic High SHDN Input Bias Current Gain Bandwidth Product Phase Margin Gain Margin Slew Rate Input Voltage Noise Density Input Current Noise Density Capacitive-Load Stability Power-Up Time Shutdown Time Enable Time from Shutdown Input Capacitance Total Harmonic Distortion Settling Time to 0.01% tON tSHDN tEN CIN THD tS fIN = 1kHz, VOUT = 2Vp-p, AV = +1V/V AV = +1V/V, VOUT = 2VSTEP MAX4041 and MAX4043 only MAX4041 and MAX4043 only SYMBOL IOUT(SHDN) VIL VIH IIH, IIL GBW m Gm SR en in f = 1kHz f = 1kHz AVCL = +1V/V, no sustained oscillations CONDITIONS SHDN = VEE = 0, MAX4041/MAX4043 only (Note 1) MAX4041/MAX4043 only MAX4041/MAX4043 only MAX4041/MAX4043 only 0.7 x VCC 40 90 68 18 40 70 0.05 200 200 50 150 3 0.05 50 120 MIN TYP 20 MAX 100 0.3 x VCC UNITS nA V V nA kHz degrees dB V/ms nV/Hz pA/Hz pF s s s pF % s
MAX4040-MAX4044
ELECTRICAL CHARACTERISTICS--TA = TMIN to TMAX
(VCC = +5.0V, VEE = 0, VCM = 0, VOUT = VCC / 2, SHDN = VCC, RL = 100k tied to VCC / 2, unless otherwise noted.) (Note 2) PARAMETER Supply-Voltage Range Supply Current per Amplifier Shutdown Supply Current per Amplifier Input Offset Voltage Input Offset Voltage Drift Input Bias Current Input Offset Current SYMBOL VCC ICC ICC(SHDN) SHDN = VEE, MAX4041 and MAX4043 only MAX4044ESA VOS TCVOS IB IOS VEE VCM VCC VEE VCM VCC VEE VCM VCC MAX404_EU_ All other packages 2 20 8 CONDITIONS Inferred from PSRR test MIN 2.4 TYP MAX 5.5 28 6.0 4.5 5.0 3.5 V/C nA nA mV UNITS V A A
_______________________________________________________________________________________
3
Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps MAX4040-MAX4044
ELECTRICAL CHARACTERISTICS--TA = TMIN to TMAX (continued)
(VCC = +5.0V, VEE = 0, VCM = 0, VOUT = VCC / 2, SHDN = VCC, RL = 100k tied to VCC / 2, unless otherwise noted.) (Note 2) PARAMETER Input Common-Mode Voltage Range Common-Mode Rejection Ratio Power-Supply Rejection Ratio Large-Signal Voltage Gain Output Voltage Swing High Output Voltage Swing Low SYMBOL VCM CMRR PSRR AVOL VOH VOL CONDITIONS Inferred from the CMRR test VEE VCM VCC 2.4V VCC 5.5V (VEE + 0.2V) VOUT (VCC - 0.2V), RL = 25k Specified as VCC - VOH, RL = 25k Specified as VEE - VOL, RL = 25k MAX404_EU_ All other packages MIN VEE 60 65 70 68 125 75 TYP MAX VCC UNITS V dB dB dB mV mV
Note 1: Tested for VEE VOUT VCC. Does not include current through external feedback network. Note 2: All devices are 100% tested at TA = +25C. All temperature limits are guaranteed by design.
__________________________________________Typical Operating Characteristics
(VCC = +5.0V, VEE = 0, VCM = VCC / 2, SHDN = VCC, RL = 100k to VCC / 2, TA = +25C, unless otherwise noted.)
MAX4041/MAX4043 SHUTDOWN SUPPLY CURRENT PER AMPLIFIER vs. TEMPERATURE
MAX4040/44-01
SUPPLY CURRENT PER AMPLIFIER vs. TEMPERATURE
20 18 16 SUPPLY CURRENT (A) 14 12 10 8 6 4 2 0 -60 -40 -20 0 20 40 60 80 100 TEMPERATURE (C) 0 VCC = +2.4V VCC = +5.5V 5 SHUTDOWN SUPPLY CURRENT (A)
SHDN = 0 4
3 VCC = +5.5V 2 VCC = +2.4V 1
-60 -40
-20
0
20
40
60
80
100
TEMPERATURE (C)
4
_______________________________________________________________________________________
MAX4040/44-01.5
Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps MAX4040-MAX4044
Typical Operating Characteristics (continued)
(VCC = +5.0V, VEE = 0, VCM = VCC / 2, SHDN = VCC, RL = 100k to VCC / 2, TA = +25C, unless otherwise noted.)
INPUT OFFSET VOLTAGE vs. TEMPERATURE
MAX4040/44-03
INPUT BIAS CURRENT vs. TEMPERATURE
MAX4040/44-04
INPUT BIAS CURRENT vs. COMMON-MODE VOLTAGE (VCC = 2.4V)
VCC = +2.4V
MAX4040/44-5
400
0 VCM = 0 VCC = +2.4V INPUT BIAS CURRENT (nA) -1
5.0
INPUT OFFSET VOLTAGE (V)
300
2.5 IBIAS (nA)
200
-2
VCC = +5.5V
0
100
-3
-2.5
0 -60 -40 -20 0 20 40 60 80 100 TEMPERATURE (C)
-4 -60 -40 -20 0 20 40 60 80 100 TEMPERATURE (C)
-5.0 0 0.2 0.6 1.0 VCM (V) 1.4 1.8 2.2
INPUT BIAS CURRENT vs. COMMON-MODE VOLTAGE (VCC = 5.5V)
MAX4040/44-06
OUTPUT SWING HIGH vs. TEMPERATURE
RL TO VEE 100 VOLTAGE FROM VCC (mV) 80 60 40 20 VCC = +5.5V, RL = 100k VCC = +2.4V, RL = 100k -60 -40 -20 0 20 40 60 80 100 VCC = +2.4V, RL = 10k
MAX4040/44-07
5.0 VCC = +5.5V 2.5 IBIAS (nA)
120
0
VCC = +5.5V, RL = 20k
-2.5
-5.0 0 0.5 1.5 2.5 VCM (V) 3.5 4.5 5.5
0
TEMPERATURE (C)
OUTPUT SWING LOW vs. TEMPERATURE
RL TO VCC 100 VOLTAGE FROM VEE (mV) 80 60 VCC = +5.5V, RL = 20k 40 VCC = +2.4V, RL = 10k 20 0 -60 VCC = +5.5V, RL = 100k VCC = +2.4V, RL = 100k -40 -20 0 20 40 60 80 100 TEMPERATURE (C)
MAX4040/44-08
COMMON-MODE REJECTION vs. TEMPERATURE
MAX4040/44-09
120
-80 COMMON-MODE REJECTION (dB)
-85
-90
VCC = +2.4V
-95
VCC = +5.5V
-100 -60 -40 -20 0 20 40 60 80 100 TEMPERATURE (C)
_______________________________________________________________________________________
5
Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps MAX4040-MAX4044
____________________________________Typical Operating Characteristics (continued)
(VCC = +5.0V, VEE = 0, VCM = VCC / 2, SHDN = VCC, RL = 100k to VCC / 2, TA = +25C, unless otherwise noted.)
OPEN-LOOP GAIN vs. OUTPUT SWING LOW (VCC = +2.4V, RL TIED TO VCC)
MAX4040/44-10
OPEN-LOOP GAIN vs. OUTPUT SWING HIGH (VCC = +2.4V, RL TIED TO VEE)
MAX4040/44-11
OPEN-LOOP GAIN vs. OUTPUT SWING LOW (VCC = +5.5V, RL TIED TO VCC)
100 90 GAIN (dB) 80 70 60 50 40
MAX4040/44-12
100 90 RL = 100k 80 GAIN (dB) 70 60 50 40 30 0 100 200 300 400 RL = 10k
100 90 80 GAIN (dB) 70 60 50 40 30 RL = 100k
110 RL = 100k RL = 20k
RL = 10k
500
0
100
200
300
400
500
0
100
200 VOUT (mV)
300
400
VOUT (mV)
VOUT (mV)
OPEN-LOOP GAIN vs. OUTPUT SWING HIGH (VCC = +5.5V, RL TIED TO VEE)
100 90 GAIN (dB) 80 70 60 50 40 0 100 200 VOUT (mV) 300 400 RL = 20k GAIN (dB) RL = 100k
MAX4040/44-13
OPEN-LOOP GAIN vs. TEMPERATURE
MAX4040/44-14
OPEN-LOOP GAIN vs. TEMPERATURE
105 100 GAIN (dB) 95 90 85 VCC = +5.5V, RL TO VEE VCC = +5.5V, RL TO VCC VCC = +2.4V, RL TO VEE VCC = +2.4V, RL TO VCC
MAX4040/44-15
110
110 105 100 95 90 85 80 75 70 -60 -40 -20 0 20 40 60 80 VCC = +2.4V, RL = 10k TO VEE VCC = +5.5V, RL = 20k TO VCC VCC = +5.5V, RL = 20k TO VEE
110
80 75 70 100 -60 -40 -20 0 20 40 60 80 100
VCC = +2.4V, RL = 10k TO VCC
TEMPERATURE (C)
TEMPERATURE (C)
GAIN AND PHASE vs. FREQUENCY (NO LOAD)
60 50 40 30 GAIN (dB) 20 10 0 -10 -20 -30 -40 10 100 1k 10k 100k FREQUENCY (Hz)
MAX4040/44-16
GAIN AND PHASE vs. FREQUENCY (CL = 100pF)
180 144 108 PHASE (DEGREES) 72 36 0 -36 -72 -108 -144 -180 60 50 40 30 GAIN (dB) 20 10 0 -10 -20 -30 -40 10 100 1k 10k 100k FREQUENCY (Hz)
MAX4040/44-17
180 144 108 PHASE (DEGREES) 72 36 0 -36 -72 -108 -144 -180
AV = +1000V/V
AV = +1000V/V
6
_______________________________________________________________________________________
Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps
____________________________________Typical Operating Characteristics (continued)
(VCC = +5.0V, VEE = 0, VCM = VCC / 2, SHDN = VCC, RL = 100k to VCC / 2, TA = +25C, unless otherwise noted.)
MAX4040-MAX4044
MAX4042/MAX4043/MAX4044 CROSSTALK vs. FREQUENCY
MAX4040/44-18
TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY
MAX4040/44-19
-60 RL = 10k -70
1
GAIN (dB)
-80
THD + NOISE (%)
0.1
-90
-100 RL = 100k RL = 10k -110 10 100 1k FREQUENCY (Hz) 10k 0.01 1 10 100 1000 FREQUENCY (Hz)
LOAD RESISTOR vs. CAPACITIVE LOAD
10% OVERSHOOT REGION OF MARGINAL STABILITY 100
MAX4040/44-20
SMALL-SIGNAL TRANSIENT RESPONSE (NONINVERTING)
MAX4040/44-21
1000
100mV IN 0V 50mV/div 100mV
RLOAD (k)
REGION OF STABLE OPERATION 10 0 250 500 CLOAD (pF) 750 1000
OUT 0V
10s/div
SMALL-SIGNAL TRANSIENT RESPONSE (INVERTING)
MAX4040/44-22
LARGE-SIGNAL TRANSIENT RESPONSE (NONINVERTING)
MAX4040/42/44-23
LARGE-SIGNAL TRANSIENT RESPONSE (INVERTING)
MAX4040/42/44-24
100mV IN 0V 50mV/div 100mV OUT 0V OUT 2V/div IN
4.5V IN 0.5V 2V/div 4.5V OUT 0.5V
+2V
-2V
+2V
-2V 100s/div
10s/div
100s/div
_______________________________________________________________________________________
7
Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps MAX4040-MAX4044
______________________________________________________________Pin Description
PIN MAX4040 SOT23-5 SO/MAX 1 2 3 4 5 -- 6 4 3 2 7 1, 5, 8 MAX4041 6 4 3 2 7 1, 5 MAX4042 -- 4 -- -- 8 -- MAX4043 MAX SO -- 4 -- -- 10 -- -- 4 -- -- 14 5, 7, 8, 10 -- MAX4044 -- 11 -- -- 4 -- NAME FUNCTION Amplifier Output. High impedance when in shutdown mode. Negative Supply. Tie to ground for single-supply operation. Noninverting Input Inverting Input Positive Supply No Connection. Not internally connected. Shutdown Input. Drive high, or tie to VCC for normal operation. Drive to VEE to place device in shutdown mode. Outputs for Amplifiers A and B. High impedance when in shutdown mode. Inverting Inputs to Amplifiers A and B Noninverting Inputs to Amplifiers A and B Shutdown Inputs for Amplifiers A and B. Drive high, or tie to VCC for normal operation. Drive to VEE to place device in shutdown mode. Outputs for Amplifiers C and D Inverting Inputs to Amplifiers C and D Noninverting Inputs to Amplifiers C and D
OUT VEE IN+ INVCC N.C.
--
--
8
--
--
--
SHDN OUTA, OUTB INA-, INBINA+, INB+ SHDNA, SHDNB OUTC, OUTD INC-, INDINC+, IND+
-- -- --
-- -- --
-- -- --
1, 7 2, 6 3, 5
1, 9 2, 8 3, 7
1, 13 2, 12 3, 11
1, 7 2, 6 3, 5
--
--
--
--
5, 6
6, 9
--
-- -- --
-- -- --
-- -- --
-- -- --
-- -- --
-- -- --
8, 14 9, 13 10, 12
_______________Detailed Description
Rail-to-Rail Input Stage
The MAX4040-MAX4044 have rail-to-rail inputs and rail-to-rail output stages that are specifically designed for low-voltage, single-supply operation. The input stage consists of separate NPN and PNP differential stages, which operate together to provide a commonmode range extending to both supply rails. The crossover region of these two pairs occurs halfway between VCC and VEE. The input offset voltage is typically 200V. Low operating supply voltage, low supply current, rail-to-rail common-mode input range, and railto-rail outputs make this family of operational amplifiers
8
an excellent choice for precision or general-purpose, low-voltage battery-powered systems. Since the input stage consists of NPN and PNP pairs, the input bias current changes polarity as the commonmode voltage passes through the crossover region. Match the effective impedance seen by each input to reduce the offset error caused by input bias currents flowing through external source impedances (Figures 1a and 1b). The combination of high source impedance plus input capacitance (amplifier input capacitance plus stray capacitance) creates a parasitic pole that produces an underdamped signal response. Reducing input capacitance or placing a small capacitor across the feedback resistor improves response in this case.
_______________________________________________________________________________________
Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps
The MAX4040-MAX4044 family's inputs are protected from large differential input voltages by internal 2.2k series resistors and back-to-back triple-diode stacks across the inputs (Figure 2). For differential input voltages (much less than 1.8V), input resistance is typically 45M. For differential input voltages greater than 1.8V, input resistance is around 4.4k, and the input bias current can be approximated by the following equation: IBIAS = (VDIFF - 1.8V) / 4.4k In the region where the differential input voltage approaches 1.8V, the input resistance decreases exponentially from 45M to 4.4k as the diode block begins conducting. Conversely, the bias current increases with the same curve.
MAX4040-MAX4044
VIN R3
MAX4040- MAX4044
R3 = R1
R2
R1
R2
Rail-to-Rail Output Stage
Figure 1a. Minimizing Offset Error Due to Input Bias Current (Noninverting)
MAX4040- MAX4044
R3
The MAX4040-MAX4044 output stage can drive up to a 25k load and still swing to within 60mV of the rails. Figure 3 shows the output voltage swing of a MAX4040 configured as a unity-gain buffer, powered from a single +4.0V supply voltage. The output for this setup typically swings from (VEE + 10mV) to (VCC - 10mV) with a 100k load.
Applications Information
Power-Supply Considerations
The MAX4040-MAX4044 operate from a single +2.4V to +5.5V supply (or dual 1.2V to 2.75V supplies) and consume only 10A of supply current per amplifier. A high power-supply rejection ratio of 85dB allows the amplifiers to be powered directly off a decaying battery voltage, simplifying design and extending battery life.
R3 = R1 VIN
R2
R1
R2
Power-Up Settling Time
Figure 1b. Minimizing Offset Error Due to Input Bias Current (Inverting)
The MAX4040-MAX4044 typically require 200s to power up after VCC is stable. During this start-up time, the output is indeterminant. The application circuit should allow for this initial delay.
IN+ 2.2k
IN2.2k
Figure 2. Input Protection Circuit
_______________________________________________________________________________________ 9
Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps MAX4040-MAX4044
MAX4040-44 fig03 MAX4040-44 fig04
1V/div
RL = 100k TIED TO VEE VIN = 4.0V fIN = 1kHz
VIN = 2V RL = 100k TIED TO VEE OUT SHDN 5V/div
1V/div
IN
OUT
1V/div
200s/div
200s/div
Figure 3. Rail-to-Rail Input/Output Voltage Range
Figure 4. Shutdown Enable/Disable Output Voltage
1200 VCC = 5.5V, VOH = 200mV OUTPUT SOURCE CURRENT (A) 1000 800 600 400 200 0 -60 -40 -20 0 VCC = 2.4V, VOH = 100mV VCC = 5.5V, VOH = 50mV VCC = 2.4V, VOH = 50mV 20 40 60 80 100 TEMPERATURE (C) VCC = 2.4V, VOH = 200mV
The MAX4041 (single) and MAX4043 (dual) feature a low-power shutdown mode. When the shutdown pin (SHDN) is pulled low, the supply current drops to 1A per amplifier, the amplifier is disabled, and the outputs enter a high-impedance state. Pulling SHDN high or leaving it floating enables the amplifier. Take care to ensure that parasitic leakage current at the SHDN pin does not inadvertently place the part into shutdown mode when SHDN is left floating. Figure 4 shows the output voltage response to a shutdown pulse. The logic threshold for SHDN is always referred to VCC / 2 (not to GND). When using dual supplies, pull SHDN to VEE to enter shutdown mode.
VCC = 5.5V, VOH = 100mV
Load-Driving Capability
The MAX4040-MAX4044 are fully guaranteed over temperature and supply voltage to drive a maximum resistive load of 25k to VCC / 2, although heavier loads can be driven in many applications. The rail-to-rail output stage of the amplifier can be modeled as a current source when driving the load toward VCC, and as a current sink when driving the load toward VEE. The magnitude of this current source/sink varies with supply voltage, ambient temperature, and lot-to-lot variations of the units. Figures 5a and 5b show the typical current source and sink capability of the MAX4040-MAX4044 family as a function of supply voltage and ambient temperature. The contours on the graph depict the output current value, based on driving the output voltage to within 50mV, 100mV, and 200mV of either power-supply rail.
Figure 5a. Output Source Current vs. Temperature
OUTPUT SINK CURRENT (A)
2500 2000 1500 1000 500 0 -60 -40
VCC = 5.5V, VOL = 200mV VCC = 2.4V, VOL = 200mV VCC = 5.5V, VOL = 100mV
VCC = 2.4V, VOL = 100mV VCC = 5.5V, VOL = 50mV VCC = 2.4V, VOL = 50mV -20 0 20 40 60 80 100 TEMPERATURE (C)
Figure 5b. Output Sink Current vs. Temperature
10 ______________________________________________________________________________________
MAX4040-44 fig05b
3000
MAX4040-44 fig05a
Shutdown Mode
Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps
For example, a MAX4040 running from a single +2.4V supply, operating at TA = +25C, can source 240A to within 100mV of VCC and is capable of driving a 9.6k load resistor to VEE: RL = 2.4V - 0.1V = 9.6k to VEE 240A
MAX4040- MAX4044
RISO
MAX4040-MAX4044
The same application can drive a 4.6k load resistor when terminated in VCC / 2 (+1.2V in this case).
RL
CL
Driving Capacitive Loads
The MAX4040-MAX4044 are unity-gain stable for loads up to 200pF (see Load Resistor vs. Capacitive Load graph in Typical Operating Characteristics). Applications that require greater capacitive drive capability should use an isolation resistor between the output and the capacitive load (Figures 6a-6c). Note that this alternative results in a loss of gain accuracy because RISO forms a voltage divider with the load resistor.
AV = RL 1 RL + RISO
Figure 6a. Using a Resistor to Isolate a Capacitive Load from the Op Amp
MAX4040/42/44 fig06b
Power-Supply Bypassing and Layout
The MAX4040-MAX4044 family operates from either a single +2.4V to +5.5V supply or dual 1.2V to 2.75V supplies. For single-supply operation, bypass the power supply with a 100nF capacitor to VEE (in this case GND). For dual-supply operation, both the V CC and VEE supplies should be bypassed to ground with separate 100nF capacitors. Good PC board layout techniques optimize performance by decreasing the amount of stray capacitance at the op amp's inputs and output. To decrease stray capacitance, minimize trace lengths by placing external components as close as possible to the op amp. Surface-mount components are an excellent choice.
50mV/div
IN
50mV/div
OUT
100s/div RISO = NONE, RL = 100k, CL = 700pF
Figure 6b. Pulse Response without Isolating Resistor
MAX4040/42/44 fig06c
Using the MAX4040-MAX4044 as Comparators
Although optimized for use as operational amplifiers, the MAX4040-MAX4044 can also be used as rail-to-rail I/O comparators. Typical propagation delay depends on the input overdrive voltage, as shown in Figure 7. External hysteresis can be used to minimize the risk of output oscillation. The positive feedback circuit, shown in Figure 8, causes the input threshold to change when the output voltage changes state. The two thresholds create a hysteresis band that can be calculated by the following equations: VHYST = VHI - VLO VLO = VIN x R2 / (R1 + (R1 x R2 / RHYST) + R2) V HI = [(R2 / R1 x V IN ) + (R2 / R HYST ) x V CC ] / (1 + R1 / R2 + R2 / RHYST)
50mV/div
IN
50mV/div
OUT
100s/div RISO = 1k, RL = 100k, CL = 700pF
Figure 6c. Pulse Response with Isolating Resistor
11
______________________________________________________________________________________
Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps MAX4040-MAX4044
MAX4040-44 fig07
10,000
INPUT VOH
VHI VLO
HYSTERESIS
1000 tPD (s)
tPD+; VCC = +5V tPD-; VCC = +5V
VOH OUTPUT VOL
100 tPD+; VCC = +2.4V tPD-; VCC = +2.4V 10 0 10 20 30 40 50 60 70 80 VOD (mV) 90 100 VOUT VIN R1 VCC RHYST
Figure 7. Propagation Delay vs. Input Overdrive
R2
VEE
MAX4040- MAX4044
The MAX4040-MAX4044 contain special circuitry to boost internal drive currents to the amplifier output stage. This maximizes the output voltage range over which the amplifiers are linear. In an open-loop comparator application, the excursion of the output voltage is so close to the supply rails that the output stage transistors will saturate, causing the quiescent current to increase from the normal 10A. Typical quiescent currents increase to 35A for the output saturating at VCC and 28A for the output at VEE.
VEE
Figure 8. Hysteresis Comparator Circuit
ILOAD R1 VCC R2
Using the MAX4040-MAX4044 as Ultra-Low-Power Current Monitors
The MAX4040-MAX4044 are ideal for applications powered from a battery stack. Figure 9 shows an application circuit in which the MAX4040 is used for monitoring the current of a battery stack. In this circuit, a current load is applied, and the voltage drop at the battery terminal is sensed. The voltage on the load side of the battery stack is equal to the voltage at the emitter of Q1, due to the feedback loop containing the op amp. As the load current increases, the voltage drop across R1 and R2 increases. Thus, R2 provides a fraction of the load current (set by the ratio of R1 and R2) that flows into the emitter of the PNP transistor. Neglecting PNP base current, this current flows into R3, producing a ground-referenced voltage proportional to the load current. Scale R1 to give a voltage drop large enough in comparison to VOS of the op amp, in order to minimize errors. The output voltage of the application can be calculated using the following equation: VOUT = [ILOAD x (R1 / R2)] x R3
12
Q1 VOUT
R3
MAX4040
VEE
Figure 9. Current Monitor for a Battery Stack
For a 1V output and a current load of 50mA, the choice of resistors can be R1 = 2, R2 = 100k, R3 = 1M. The circuit consumes less power (but is more susceptible to noise) with higher values of R1, R2, and R3.
______________________________________________________________________________________
Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps MAX4040-MAX4044
_____________________________________________Pin Configurations (continued)
TOP VIEW
N.C. 1 IN- 2
8 7
N.C. VCC OUT N.C.
N.C. ININ+
1 2
8 7
SHDN VCC OUT N.C.
OUTA 1 INA- 2
8 7
VCC OUTB INBINB+
MAX4040
IN+ 3 6 5 VEE 4
MAX4041
3 6 5 INA+ 3 VEE 4 VEE 4
MAX4042
6 5
SO/MAX
SO/MAX
SO/MAX
OUTA 1 INAINA+ VEE SHDNA 2 3 4 5
10 VCC 9 OUTB INBINB+ SHDNB
OUTA 1 INAINA+ 2 3
14 VCC 13 OUTB 12 INB-
OUTA 1 INAINA+ 2 3
14 OUTD 13 IND12 IND+
MAX4043
8 7 6
VEE 4 N.C. 5 SHDNA 6 N.C. 7
MAX4043
11 INB+ 10 N.C. 9 8 SHDNB N.C.
VCC 4 INB+ 5 INB- 6 OUTB 7
MAX4044
11 VEE 10 INC+ 9 8 INCOUTC
MAX
SO
SO
___________________Chip Information
MAX4040/MAX4041 TRANSISTOR COUNT: 234 MAX4042/MAX4043 TRANSISTOR COUNT: 466 MAX4044 TRANSISTOR COUNT: 932 SUBSTRATE CONNECTED TO VEE
______________________________________________________________________________________
13
Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps MAX4040-MAX4044
________________________________________________________Package Information
SOT5L.EPS
14
______________________________________________________________________________________
Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps
___________________________________________Package Information (continued)
8LUMAXD.EPS
MAX4040-MAX4044
______________________________________________________________________________________
15
Single/Dual/Quad, Low-Cost, SOT23, Micropower, Rail-to-Rail I/O Op Amps MAX4040-MAX4044
Package Information (continued)
10LUMAXB.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.
16 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 1998 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

▲Up To Search▲

Price & Availability of MAX4040

	To Download MAX4040 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .