Data Sheet
OPAx891 180MHz, 0.95nV/√Hz, Ultra-Low THD Operational Amplifiers
1 Features
- Ultra-low 0.95nV/√Hz voltage noise
- High speed:
- 180MHz unity gain bandwidth
- 140MHz bandwidth at a gain of 2V/V (–1V/V)
- 105V/μs slew rate
- Very low distortion
- THD = –91dBc (f = 1MHz, RL = 150Ω)
- THD = –100dBc (f = 1MHz, RL = 1kΩ)
- THD+N = –137dBc (f = 1kHz, BW = 80kHz)
- Low 0.2mV (typical) and 1mV (maximum) input offset voltage at 25°C
- 200mA output current drive (typical)
- Typical operation from ±4.5V to ±18V
- Offset nulling pins on the OPA891
2 Applications
- Low-noise, wide-band amplifier for industrial applications
- Voltage-controlled oscillators
- Active filters
- Video amplifiers
- Cable drivers
- Ultrasound scanners
- Vector signal transceiver (VST)
- Professional audio mixer or control surface
- Professional microphones and wireless systems
- Professional speaker systems
- Professional audio amplifier
- Soundbar
- Turntable
- Professional video camera
- Guitar and other instrument amplifier
- Data acquisition (DAQ)
3 Description
The OPA891 and OPA2891 (OPAx891) are ultra-low voltage noise, high-speed voltage feedback amplifiers that are an excellent choice for applications requiring low voltage noise, including communications and imaging. The single-amplifier OPA891 and the dual-amplifier OPA2891 offer very good ac performance with 140MHz bandwidth, gain (G) = 2V/V, 105V/μs slew rate, and 70ns settling time (0.1%). The OPAx891 are unity-gain stable with 180MHz bandwidth. These amplifiers have a high drive capability of 200mA and draw only 7.5mA supply current per channel. With –100dBc of total harmonic distortion (THD) at f = 1MHz and a very low noise of 0.95nV/√Hz, the OPAx891 are designed for applications requiring low distortion and low noise such as buffering analog-to-digital converters.
Device Information
| PART NUMBER | AMPLIFIERS | PACKAGE(1) | PACKAGE SIZE(2) |
|---|---|---|---|
| OPA891 | One | D (SOIC, 8) | 4.9mm × 6mm |
| DGN (HVSSOP, 8) | 3mm × 4.9mm | ||
| OPA2891 | Two | D (SOIC, 8) | 4.9mm × 6mm |
| DGN (HVSSOP, 8) | 3mm × 4.9mm |
(1) For more information, see Section 10.
(2) The package size (length × width)
is a nominal value and includes pins, where applicable.
Ultrasound Time-Gain-Control
Circuit
Voltage and Current Noise vs
Frequency4 Pin Configuration and Functions
Figure 4-1 OPA891: D Package, 8-Pin SOIC, or DGN Package, 8-pin HVSSOP (Top View)
Table 4-1 Pin
Functions: OPA891
| PIN | TYPE | DESCRIPTION | |
|---|---|---|---|
| NAME | NO. | ||
| IN– | 2 | Input | Inverting input |
| IN+ | 3 | Input | Noninverting input |
| NC | 5 | — | No connection |
| NULL | 1, 8 | Input | Voltage offset adjust |
| OUT | 6 | Output | Output of amplifier |
| VCC– | 4 | — | Negative power supply |
| VCC+ | 7 | — | Positive power supply |
| Thermal Pad | Pad | — | Thermal pad. DGN (HVSSOP) package only. For the best thermal performance, connect this pad to a large copper plane. The thermal pad can be connected to any pin on the device, or any other potential on the board, as long as the voltage on the thermal pad remains between VCC+ and VCC–. |
Figure 4-2 OPA2891: D Package, 8-Pin SOIC, or DGN Package, 8-pin HVSSOP (Top View)
Table 4-2 Pin
Functions: OPA2891
| PIN | TYPE | DESCRIPTION | |
|---|---|---|---|
| NAME | NO. | ||
| 1IN– | 2 | Input | Channel 1 inverting input |
| 1IN+ | 3 | Input | Channel 1 noninverting input |
| 1OUT | 1 | Output | Channel 1 output |
| 2IN– | 6 | Input | Channel 2 inverting input |
| 2IN+ | 5 | Input | Channel 2 noninverting input |
| 2OUT | 7 | Output | Channel 2 output |
| VCC– | 4 | — | Negative power supply |
| VCC+ | 8 | — | Positive power supply |
| Thermal Pad | Pad | — | Thermal pad. DGN (HVSSOP) package only. For the best thermal performance, connect this pad to a large copper plane. The thermal pad can be connected to any pin on the device, or any other potential on the board, as long as the voltage on the thermal pad remains between VCC+ and VCC–. |
5 Specifications
5.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1)
| MIN | MAX | UNIT | |||
|---|---|---|---|---|---|
| VCC | Supply voltage, VCC+ – VCC– | 37 | V | ||
| VI | Input voltage | ±VCC | V | ||
| IO | Output current(2) | 240 | mA | ||
| VIO | Differential input voltage | ±1.5 | V | ||
| IIN | Continuous input current | 10 | mA | ||
| TA | Operating free-air temperature | –40 | 85 | °C | |
| TJ | Junction temperature | Any condition | 150 | °C | |
| Maximum junction temperature, continuous operation, long-term reliability(3) | 125 | ||||
| Tstg | Storage temperature | –65 | 150 | °C | |
(1) Operation outside the Absolute Maximum Ratings may cause permanent device damage. Absolute Maximum Ratings do not imply functional operation of the device at these or any other conditions beyond those listed under Recommended Operating Conditions. If used outside the Recommended Operating Conditions but within the Absolute Maximum Ratings, the device may not be fully functional, and this may affect device reliability, functionality, performance, and shorten the device lifetime.
(2) When continuously operating at any output current, do not exceed the maximum junction temperature. Keep the output current less than the absolute maximum rating regardless of time interval.
(3) The maximum junction temperature for continuous operation is limited by package constraints. Operation greater than this temperature can result in reduced reliability, lifetime of the device, or both.
5.2 ESD Ratings
| VALUE | UNIT | |||
|---|---|---|---|---|
| V(ESD) | Electrostatic discharge | Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins(1) | ±4000 | V |
| Charged device model (CDM), per ANSI/ESDA/JEDEC JS-002, all pins(2) | ±1500 | |||
(1) JEDEC document JEP155 states that 500V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250V CDM allows safe manufacturing with a standard ESD control process.