The OPA657 device combines a high-gain bandwidth, low-distortion, voltage-feedback operational amplifier with a low-voltage noise JFET-input stage to offer a very high dynamic range amplifier for high-precision ADC (analog-to-digital converter) driving or wideband transimpedance applications. Photodiode applications see improved noise and bandwidth using this decompensated, high-gain bandwidth amplifier.
Very low level signals can be significantly amplified in a single OPA657 gain stage with exceptional bandwidth and accuracy. Having a high 1.6-GHz gain bandwidth product gives greater than 10-MHz signal bandwidths up to gains of 160 V/V (44 dB). The very low input bias current and capacitance supports this performance even for relatively high source impedances.
Broadband photodetector applications benefit from the low-voltage noise JFET inputs for the OPA657. The JFET input contributes virtually no current noise while for broadband applications, a low voltage noise is also required. The low 4.8 nV/√Hz input voltage noise provides exceptional input sensitivity for higher bandwidth applications. The example shown below gives a total equivalent input noise current of 1.8 pA/√Hz over a 10-MHz bandwidth.
PART NUMBER | PACKAGE | BODY SIZE (NOM) |
---|---|---|
OPA657 | SOT-23 (5) | 2.90 mm × 1.60 mm |
SOIC (8) | 4.90 mm × 3.91 mm |
Changes from E Revision (December 2008) to F Revision
Changes from D Revision (March 2006) to E Revision
DEVICE | VS (V) | BW (MHz) | SLEW RATE (V/μs) | VOLTAGE NOISE (nV/√Hz) | AMPLIFIER DESCRIPTION |
---|---|---|---|---|---|
OPA657 | ±5 | 1600 | 700 | 4.8 | Gain of +7 stable FET Input |
OPA656 | ±5 | 230 | 290 | 7 | Unity-Gain Stable FET-Input |
OPA659 | ±6 | 350 | 2550 | 8.9 | Unity-Gain Stable FET-Input |
LMH6629 | 5 | 4000 | 1600 | 0.69 | Gain of +10 stable Bipolar Input |
THS4631 | ±15 | 210 | 1000 | 7 | Unity-Gain Stable FET-Input |
OPA857 | 5 | 4750 | 220 | — | Programmable Gain (5 kΩ / 20 kΩ) Transimpedance Amplifier |
PIN | I/O | DESCRIPTION | ||
---|---|---|---|---|
NAME | SOIC | SOT-23 | ||
NC | 1 | — | — | No Connection |
5 | ||||
8 | ||||
VIN– | 2 | 4 | I | Inverting Input |
VIN+ | 3 | 3 | I | Noninverting Input |
–VS | 4 | 2 | POW | Negative Power Supply |
VOUT | 6 | 1 | O | Output of amplifier |
+VS | 7 | 5 | POW | Positive Power Supply |