SLOS896B December 2014 – January 2017 OPA2314-Q1 , OPA314-Q1 , OPA4314-Q1
PRODUCTION DATA.
The OPAx314-Q1 series is a family of single–, and dual–, and quad-channel operational amplifiers (op amps) that represents a new generation of low-power, general-purpose CMOS amplifiers. Rail-to-rail input and output swings, low quiescent current (150 μA typically at 5 VS) combined with a wide bandwidth of 3 MHz, and very low noise (14 nV/√Hz at 1 kHz) make this device family very attractive for a variety of battery-powered applications that require a good balance between cost and performance. The low-input bias current supports applications with megaohm source impedances.
The robust design of the OPAx314-Q1 series provides ease-of-use to the circuit designer: unity-gain stability with capacitive loads of up to 300 pF, an integrated RF and EMI rejection filter, no phase reversal in overdrive conditions, and high electrostatic discharge (ESD) protection (4-kV HBM).
The device is optimized for low-voltage operation as low as 1.8 V (±0.9 V) and up to 5.5 V (±2.75 V), and is specified over the full extended temperature range of –40°C to +125°C.
The single-channel device, OPA314-Q1, is offered in the SOT-23 package and the dual-channel device, OPA2314-Q1, is offered in the VSSOP (8) package. The quad-channel OPA4314-Q1 is available in the 14-pin TSSOP package.
PART NUMBER | PACKAGE | BODY SIZE (NOM) |
---|---|---|
OPA314-Q1 | SOT-23 (5) | 2.90 mm × 1.60 mm |
OPA2314-Q1 | VSSOP (8) | 4.90 mm × 3.91 mm |
OPA4314-Q1 | TSSOP (14) | 5.00 mm × 4.40 mm |
Changes from A Revision (January 2015) to B Revision
Changes from * Revision (December 2014) to A Revision
PIN | I/O | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
–IN | 4 | I | Inverting input |
+IN | 3 | I | Noninverting input |
OUT | 1 | O | Output |
V– | 2 | — | Negative supply or ground (for single-supply operation). |
V+ | 5 | — | Positive supply |
PIN | I/O | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
–IN A | 2 | I | Inverting input, channel A |
+IN A | 3 | I | Noninverting input, channel A |
–IN B | 6 | I | Inverting input, channel B |
+IN B | 5 | I | Noninverting input, channel B |
OUT A | 1 | O | Output, channel A |
OUT B | 7 | O | Output, channel B |
V– | 4 | — | Negative supply or ground (for single-supply operation). |
V+ | 8 | — | Positive supply |
PIN | I/O | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
–IN A | 2 | I | Inverting input, channel A |
+IN A | 3 | I | Noninverting input, channel A |
–IN B | 6 | I | Inverting input, channel B |
+IN B | 5 | I | Noninverting input, channel B |
–IN C | 9 | I | Inverting input, channel C |
+IN C | 10 | I | Noninverting input, channel C |
–IN D | 13 | I | Inverting input, channel D |
+IN D | 12 | I | Noninverting input, channel D |
OUT A | 1 | O | Output, channel A |
OUT B | 7 | O | Output, channel B |
OUT C | 8 | O | Output, channel C |
OUT D | 14 | O | Output, channel D |
V– | 11 | — | Negative supply or ground (for single-supply operation). |
V+ | 4 | — | Positive supply |
MIN | MAX | UNIT | ||
---|---|---|---|---|
Supply voltage | 7 | V | ||
Voltage(2) | Signal input terminals | (V–) – 0.5 | (V+) + 0.5 | V |
Current(2) | Signal input terminals | ±10 | mA | |
Output short-circuit(3) | Continuous | mA | ||
Operating temperature, TA | –40 | 150 | °C | |
Junction temperature, TJ | 150 | °C | ||
Storage temperature, Tstg | –65 | 150 | °C |
VALUE | UNIT | ||||
---|---|---|---|---|---|
V(ESD) | Electrostatic discharge | Human body model (HBM), per AEC Q100-002(1) | ±2000 | V | |
Charged device model (CDM), per AEC Q100-011 | ±1000 |
MIN | NOM | MAX | UNIT | ||
---|---|---|---|---|---|
VS | Supply voltage | 1.8 (±0.9) | 5.5 (±2.75) | V | |
TA | Ambient operating temperature | –40 | 125 | °C |
THERMAL METRIC(1) | OPA314-Q1 | UNIT | |
---|---|---|---|
DBV (SOT-23) | |||
5 PINS | |||
RθJA | Junction-to-ambient thermal resistance(2) | 221.7 | °C/W |
RθJC(top) | Junction-to-case(top) thermal resistance(3) | 144.7 | °C/W |
RθJB | Junction-to-board thermal resistance(4) | 49.7 | °C/W |
ψJT | Junction-to-top characterization parameter(5) | 26.1 | °C/W |
ψJB | Junction-to-board characterization parameter(6) | 49 | °C/W |
RθJC(bot) | Junction-to-case(bottom) thermal resistance(7) | N/A | °C/W |
THERMAL METRIC(1) | OPA2314-Q1 | UNIT | |
---|---|---|---|
DGK (VSSOP) | |||
8 PINS | |||
RθJA | Junction-to-ambient thermal resistance(2) | 138.4 | °C/W |
RθJC(top) | Junction-to-case(top) thermal resistance(3) | 89.5 | °C/W |
RθJB | Junction-to-board thermal resistance(4) | 78.6 | °C/W |
ψJT | Junction-to-top characterization parameter(5) | 29.9 | °C/W |
ψJB | Junction-to-board characterization parameter(6) | 78.1 | °C/W |
RθJC(bot) | Junction-to-case(bottom) thermal resistance(7) | N/A | °C/W |
THERMAL METRIC(1) | OPA4314-Q1 | UNIT | |
---|---|---|---|
PW (TSSOP) | |||
14 PINS | |||
RθJA | Junction-to-ambient thermal resistance(2) | 121 | °C/W |
RθJC(top) | Junction-to-case(top) thermal resistance(3) | 49.4 | °C/W |
RθJB | Junction-to-board thermal resistance(4) | 62.8 | °C/W |
ψJT | Junction-to-top characterization parameter(5) | 5.9 | °C/W |
ψJB | Junction-to-board characterization parameter(6) | 62.2 | °C/W |
RθJC(bot) | Junction-to-case(bottom) thermal resistance(7) | N/A | °C/W |
PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNIT | |
---|---|---|---|---|---|---|
OFFSET VOLTAGE | ||||||
VOS | Input offset voltage | VCM = (VS+) – 1.3 V | 0.5 | 2.5 | mV | |
dVOS/dT | Input offset voltage vs temperature | 1 | μV/°C | |||
PSRR | vs power supply | VCM = (VS+) – 1.3 V | 78 | 92 | dB | |
Input offset voltage overtemperature | 74 | dB | ||||
Channel separation, DC | At DC | 10 | µV/V | |||
INPUT VOLTAGE RANGE | ||||||
VCM | Common-mode voltage range | (V–) – 0.2 | (V+) + 0.2 | V | ||
CMRR | Common-mode rejection ratio | VS = 1.8 V to 5.5 V, (VS–) – 0.2 V < VCM < (VS+) – 1.3 V | 75 | 96 | dB | |
VS = 5.5 V, VCM = –0.2 V to 5.7 V (2) | 66 | 80 | dB | |||
Common-mode rejection ratio overtemperature | VS = 1.8 V, (VS–) – 0.2 V < VCM < (VS+) – 1.3 V | 70 | 86 | dB | ||
VS = 5.5 V, (VS–) – 0.2 V < VCM < (VS+) – 1.3 V | 73 | 90 | dB | |||
VS = 5.5 V, VCM = –0.2 V to 5.7 V (2) | 60 | dB | ||||
INPUT BIAS CURRENT | ||||||
IB | Input bias current | ±0.2 | ±10 | pA | ||
Input bias current overtemperature | ±600 | pA | ||||
IOS | Input offset current | ±0.2 | ±10 | pA | ||
Input offset current overtemperature | ±600 | pA | ||||
NOISE | ||||||
Input voltage noise (peak-to-peak) | f = 0.1 Hz to 10 Hz | 5 | μVPP | |||
en | Input voltage noise density | f = 10 kHz | 13 | nV/√Hz | ||
f = 1 kHz | 14 | nV/√Hz | ||||
in | Input current noise density | f = 1 kHz | 5 | fA/√Hz | ||
INPUT CAPACITANCE | ||||||
CIN | Differential | VS = 5 V | 1 | pF | ||
Common-mode | VS = 5 V | 5 | pF | |||
OPEN-LOOP GAIN | ||||||
AOL | Open-loop voltage gain | VS = 1.8 V, 0.2 V < VO < (V+) – 0.2 V, RL = 10 kΩ | 90 | 115 | dB | |
VS = 5.5 V, 0.2 V < VO < (V+) – 0.2 V, RL = 10 kΩ | 100 | 128 | dB | |||
VS = 1.8 V, 0.5 V < VO < (V+) – 0.5 V, RL = 2 kΩ(2) | 90 | 100 | dB | |||
VS = 5.5 V, 0.5 V < VO < (V+) – 0.5 V, RL = 2 kΩ(2) | 94 | 110 | dB | |||
Open-loop voltage gain overtemperature | VS = 5.5 V, 0.2 V < VO < (V+) – 0.2 V, RL = 10 kΩ | 90 | 110 | dB | ||
VS = 5.5 V, 0.5 V < VO < (V+) – 0.2 V, RL = 2 kΩ | 100 | dB | ||||
Phase margin | VS = 5 V, G = 1, RL = 10 kΩ | 65 | degrees | |||
FREQUENCY RESPONSE | ||||||
GBW | Gain-bandwidth product | VS = 1.8 V, RL = 10 kΩ, CL = 10 pF | 2.7 | MHz | ||
VS = 5 V, RL = 10 kΩ, CL = 10 pF | 3 | MHz | ||||
SR | Slew rate (3) | VS = 5 V, G = 1 | 1.5 | V/μs | ||
tS | Settling time | To 0.1%, VS = 5 V, 2-V step , G = 1 | 2.3 | μs | ||
To 0.01%, VS = 5 V, 2-V step , G = 1 | 3.1 | μs | ||||
Overload recovery time | VS = 5 V, VIN × Gain > VS | 5.2 | μs | |||
THD+N | Total harmonic distortion + noise (4) | VS = 5 V, VO = 1 VRMS, G = 1, f = 1 kHz, RL = 10 kΩ | 0.001% | |||
OUTPUT | ||||||
VO | Voltage output swing from supply rails | VS = 1.8 V, RL = 10 kΩ | 5 | 15 | mV | |
VS = 5.5 V, RL = 10 kΩ | 5 | 20 | mV | |||
VS = 1.8 V, RL = 2 kΩ | 15 | 30 | mV | |||
VS = 5.5 V, RL = 2 kΩ | 22 | 40 | mV | |||
Voltage output swing from supply rails overtemperature | VS = 5.5 V, RL = 10 kΩ | 30 | mV | |||
VS = 5.5 V, RL = 2 kΩ | 60 | mV | ||||
ISC | Short-circuit current | VS = 5 V | ±20 | mA | ||
RO | Open-loop output impedance | VS = 5.5 V, f = 100 Hz | 570 | Ω | ||
POWER SUPPLY | ||||||
VS | Specified voltage range | 1.8 | 5.5 | V | ||
IQ | Quiescent current per amplifier | VS = 1.8 V, IO = 0 mA | 130 | 180 | µA | |
VS = 5 V, IO = 0 mA | 150 | 190 | µA | |||
Quiescent current per amplifier overtemperature | VS = 5 V, IO = 0 mA | 220 | µA | |||
Power-on time | VS = 0 V to 5 V, to 90% IQ level | 44 | µs | |||
TEMPERATURE | ||||||
Specified range | –40 | 125 | °C | |||
Operating range | –40 | 150 | °C | |||
Storage range | –65 | 150 | °C |
TITLE | FIGURE |
---|---|
Open-Loop Gain and Phase vs Frequency | Figure 1 |
Open-Loop Gain vs Temperature | Figure 2 |
Quiescent Current vs Supply Voltage | Figure 3 |
Quiescent Current vs Temperature | Figure 4 |
Offset Voltage Production Distribution | Figure 5 |
Offset Voltage Drift Distribution | Figure 6 |
Offset Voltage vs Common-Mode Voltage (Maximum Supply) | Figure 7 |
Offset Voltage vs Temperature | Figure 8 |
CMRR and PSRR vs Frequency (RTI) | Figure 9 |
CMRR and PSRR vs Temperature | Figure 10 |
0.1-Hz to 10-Hz Input Voltage Noise (5.5 V) | Figure 11 |
Input Voltage Noise Spectral Density vs Frequency (1.8 V, 5.5 V) | Figure 12 |
Input Voltage Noise vs Common-Mode Voltage (5.5 V) | Figure 13 |
Input Bias and Offset Current vs Temperature | Figure 14 |
Open-Loop Output Impedance vs Frequency | Figure 15 |
Maximum Output Voltage vs Frequency and Supply Voltage | Figure 16 |
Output Voltage Swing vs Output Current (over Temperature) | Figure 17 |
Closed-Loop Gain vs Frequency, G = 1, –1, 10 (1.8 V) | Figure 18 |
Closed-Loop Gain vs Frequency, G = 1, –1, 10 (5.5 V) | Figure 19 |
Small-Signal Overshoot vs Load Capacitance | Figure 20 |
Small-Signal Step Response, Noninverting (1.8 V) | Figure 21 |
Small-Signal Step Response, Noninverting ( 5.5 V) | Figure 22 |
Large-Signal Step Response, Noninverting (1.8 V) | Figure 23 |
Large-Signal Step Response, Noninverting ( 5.5 V) | Figure 24 |
Positive Overload Recovery | Figure 25 |
Negative Overload Recovery | Figure 26 |
No Phase Reversal | Figure 27 |
Channel Separation vs Frequency (Dual) | Figure 28 |
THD+N vs Amplitude (G = 1, 2 kΩ, 10 kΩ) | Figure 29 |
THD+N vs Amplitude (G = –1, 2 kΩ, 10 kΩ) | Figure 30 |
THD+N vs Frequency (0.5 VRMS, G = 1, 2 kΩ, 10 kΩ) | Figure 31 |
EMIRR | Figure 32 |
RL = 10 kΩ / 10 pF | VS = ±2.5 V | |
Typical units | VS = ±2.75 V | |
VS = ±2.75 V | ||
f = 1 kHz | VS = ±2.75 V | |
VS = ±2.75 V | ||
VS = 5.5 V | ||
RF = 10 kΩ | VS = ±0.9 V | G = 1 V/V |
RL = 10 kΩ | VS = ±0.9 V | G = 1 V/V |
f = 1 kHz | VS = ±2.5 V | G = 1 V/V |
BW = 80 kHz | ||
VOUT = 0.5 VRMS | VS = ±2.5 V | G = 1 V/V |
BW = 80 kHz | ||
Typical units | VS = ±2.75 V | |
RL = 10 kΩ | CL = 10 pF | |
VS = 1.8 V | ||
RL = 10 kΩ | VS = ±2.75 V | G = 1 V/V |
RF = 10 kΩ | VS = ±2.75 V | G = 1 V/V |
RL = 10 kΩ | VS = ±2.75 V | G = 1 V/V |
VS = ±2.75 V | ||
f = 1 kHz | VS = ±2.5 V | G = –1 V/V |
BW = 80 kHz | ||
PRF = –10 dBm | VS = ±2.5 V | VCM = 0 V |
The OPAx314-Q1 is a family of low-power, rail-to-rail input and output operational amplifiers. These devices operate from 1.8 V to 5.5 V, are unity-gain stable, and are suitable for a wide range of general-purpose applications. The class AB output stage is capable of driving ≤ 10-kΩ loads connected to any point between V+ and ground. The input common-mode voltage range includes both rails and allows the OPAx314-Q1 series to be used in virtually any single-supply application. Rail-to-rail input and output swing significantly increases dynamic range, especially in low-supply applications, and makes them ideal for driving sampling analog-to-digital converters (ADCs).
The OPAx314-Q1 op-amp family is fully specified and ensured for operation from 1.8 V to 5.5 V. In addition, many specifications apply from –40°C to +125°C. Parameters that vary significantly with operating voltages or temperature are shown in the Typical Characteristics section. Power-supply pins must be bypassed with 0.01-μF ceramic capacitors.
The input common-mode voltage range of the OPAx314-Q1 family extends 200 mV beyond the supply rails. This performance is achieved with a complementary input stage: an N-channel input differential pair in parallel with a P-channel differential pair. The N-channel pair is active for input voltages close to the positive rail, typically (V+) – 1.3 V to 200 mV above the positive supply. The P-channel pair is on for inputs from 200 mV below the negative supply to approximately (V+) – 1.3 V. A small transition region exists, typically (V+) – 1.4 V to (V+)
– 1.2 V, in which both pairs are on. This 200-mV transition region can vary up to 300 mV with process variation. Thus, the transition region (both stages on) can range from (V+) – 1.7 V to (V+) – 1.5 V on the low end, up to (V+) – 1.1 V to (V+) – 0.9 V on the high end. Within this transition region, PSRR, CMRR, offset voltage, offset drift, and THD may be degraded compared to device operation outside this region.
The OPAx314-Q1 family incorporates internal electrostatic discharge (ESD) protection circuits on all pins. In the case of input and output pins, this protection primarily consists of current-steering diodes connected between the input and power-supply pins. These ESD protection diodes also provide in-circuit, input overdrive protection, as long as the current is limited to 10 mA as stated in the Absolute Maximum Ratings table. Figure 33 shows how a series input resistor can be added to the driven input to limit the input current. The added resistor contributes thermal noise at the amplifier input and the value must be kept to a minimum in noise-sensitive applications.
CMRR for the OPAx314-Q1 family is specified in several ways so the best match for a given application may be used; see the Electrical Characteristics table. First, the CMRR of the device in the common-mode range below the transition region [VCM < (V+) – 1.3 V] is given. This specification is the best indicator of the capability of the device when the application requires use of one of the differential input pairs. Second, the CMRR over the entire common-mode range is specified at (VCM = –0.2 V to 5.7 V). This last value includes the variations seen through the transition region, as shown in Figure 7.
Op amps vary with regard to the susceptibility of the device to electromagnetic interference (EMI). If conducted EMI enters the op-amp, the dc offset observed at the amplifier output may shift from the nominal value while EMI is present. This shift is a result of signal rectification associated with the internal semiconductor junctions. While all op-amp pin functions can be affected by EMI, the signal input pins are likely to be the most susceptible. The OPAx314-Q1 family incorporates an internal input low-pass filter that reduces the amplifiers response to EMI. Both common-mode and differential mode filtering are provided by this filter. The filter is designed for a cutoff frequency of approximately 80 MHz (–3 dB), with a roll-off of 20 dB per decade.
Texas Instruments has developed the ability to accurately measure and quantify the immunity of an operational amplifier over a broad frequency spectrum extending from 10 MHz to 6 GHz. The EMI rejection ratio (EMIRR) metric allows op amps to be directly compared by the EMI immunity. Figure 32 shows the results of this testing on the OPAx314-Q1 family. Detailed information can also be found in the EMI Rejection Ratio of Operational Amplifiers application report, available for download from www.ti.com.
Designed as a micro-power, low-noise operational amplifier, the OPAx314-Q1 family delivers a robust output drive capability. A class AB output stage with common-source transistors is used to achieve full rail-to-rail output swing capability. For resistive loads up to 10 kΩ, the output swings typically to within 5 mV of either supply rail regardless of the power-supply voltage applied. Different load conditions change the ability of the amplifier to swing close to the rails; see Figure 17.
The OPAx314-Q1 family is powered on when the supply is connected. The device can operate as a single-supply operational amplifier or a dual-supply amplifier, depending on the application.
NOTE
Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.
The OPAx314-Q1 family is a low-power, rail-to-rail input and output operational amplifier specifically designed for portable applications. The device operates from 1.8 V to 5.5 V, is unity-gain stable, and suitable for a wide range of general-purpose applications. The class AB output stage is capable of driving ≤ 10-kΩ loads connected to any point between V+ and ground. The input common-mode voltage range includes both rails, and allows the OPAx314-Q1 family to be used in virtually any single-supply application. Rail-to-rail input and output swing significantly increases dynamic range, especially in low-supply applications, and makes the device ideal for driving sampling analog-to-digital converters (ADCs).
The OPAx314-Q1 family features a 3-MHz bandwidth and 1.5-V/μs slew rate with only 150-μA supply current per channel, providing good AC performance at very low power consumption. DC applications are also well served with a very-low input noise voltage of 14 nV/√Hz at 1 kHz, low-input bias current (0.2 pA), and an input offset voltage of 0.5 mV (typical).
When receiving low-level signals, limiting the bandwidth of the incoming signals into the system is often required. The simplest way to establish this limited bandwidth is to place an RC filter at the noninverting terminal of the amplifier, as shown in Figure 34.
If additional attenuation is needed, a multiple pole filter is required. The Sallen-Key filter can be used for this task, as shown in Figure 35. For best results, the amplifier must have a bandwidth that is eight to ten times the filter frequency bandwidth. Failure to follow this guideline can result in phase shift of the amplifier.
The OPAx314-Q1 family is designed to be used in applications where driving a capacitive load is required. As with all op amps, specific instances can occur where the OPAx314-Q1 can become unstable. The particular op-amp circuit configuration, layout, gain, and output loading are some of the factors to consider when establishing whether or not an amplifier is stable in operation. An op-amp in the unity-gain (1 V/V) buffer configuration that drives a capacitive load exhibits a greater tendency to be unstable than an amplifier operated at a higher noise gain. The capacitive load, in conjunction with the op-amp output resistance, creates a pole within the feedback loop that degrades the phase margin. The degradation of the phase margin increases as the capacitive loading increases. When operating in the unity-gain configuration, the OPAx314-Q1 remains stable with a pure capacitive load up to approximately 1 nF. The equivalent series resistance (ESR) of some very large capacitors (CL greater than 1 μF) is sufficient to alter the phase characteristics in the feedback loop such that the amplifier remains stable. Increasing the amplifier closed-loop gain allows the amplifier to drive increasingly larger capacitance. This increased capability is evident when observing the overshoot response of the amplifier at higher voltage gains; see , Figure 20.
One technique for increasing the capacitive load drive capability of the amplifier operating in a unity-gain configuration is to insert a small resistor, typically 10 Ω to 20 Ω, in series with the output, as shown in Figure 36. This resistor significantly reduces the overshoot and ringing associated with large capacitive loads. One possible problem with this technique, however, is that a voltage divider is created with the added series resistor and any resistor connected in parallel with the capacitive load. The voltage divider introduces a gain error at the output that reduces the output swing.
Some applications require differential signals. Figure 37 shows a simple circuit to convert a single-ended input of 0.1 V to 2.4 V into a differential output of ±2.3 V on a single 2.7-V supply. The output range is intentionally limited to maximize linearity. The circuit is composed of two amplifiers. One amplifier functions as a buffer and creates a voltage (VOUT+. ) The second amplifier inverts the input and adds a reference voltage to generate VOUT–. Both VOUT+ and VOUT– range from 0.1 V to 2.4 V. The difference (VDIFF) is the difference between VOUT+ and VOUT–. This makes the differential output voltage range 2.3 V.
The design requirements are as follows:
The circuit in Figure 37 takes a single-ended input signal, VIN, and generates two output signals, VOUT+ and VOUT– using two amplifiers and a reference voltage, VREF. VOUT+ is the output of the first amplifier and is a buffered version of the input signal, VIN (as shown in Equation 1). VOUT– is the output of the second amplifier which uses VREF to add an offset voltage to VIN and feedback to add inverting gain. The transfer function for VOUT– is given in Equation 2.
The differential output signal (VDIFF) is the difference between the two single-ended output signals (VOUT+ and VOUT–). Equation 3 shows the transfer function for VDIFF. By applying the conditions that R1 = R2 and R3 = R4, the transfer function is simplified into Equation 6. Using this configuration, the maximum input signal is equal to the reference voltage and the maximum output of each amplifier is equal to VREF. The differential output range is 2 × VREF. Furthermore, the common-mode voltage is one half of VREF (see Equation 7).
Linearity over the input range is key for good dc accuracy. The common-mode input range and output swing limitations determine the linearity. In general, an amplifier with rail-to-rail input and output swing is required. Bandwidth is a key concern for this design, so the OPAx314-Q1 family is selected because the bandwidth is greater than the target of 1 MHz. The bandwidth and power ratio makes this device power efficient and the low offset and drift ensure good accuracy for moderate precision applications.
Because the transfer function of VOUT– is heavily reliant on resistors (R1, R2, R3, and R4), use resistors with low tolerances to maximize performance and minimize error. This design uses resistors with resistance values of 49.9 kΩ and tolerances of 0.1%. However, if the noise of the system is a key parameter, smaller resistance values (6 kΩ or lower) can be selected to keep the overall system noise low. This ensures that the noise from the resistors is lower than the amplifier noise.
The OPAx314-Q1 family is specified for operation from 1.8 V to 5.5 V (±0.9 V to ±2.75 V); many specifications apply from –40°C to +125°C. The Typical Characteristics section presents parameters that can exhibit significant variance with regard to operating voltage or temperature.
CAUTION
Supply voltages larger than 7 V can permanently damage the device (see the Absolute Maximum Ratings table).
Place 0.1-μF bypass capacitors close to the power-supply pins to reduce errors coupling in from noisy or high-impedance power supplies. For more detailed information on bypass capacitor placement, see the Layout Guidelines section.