OPA3684

Power Supply ............................................................................... ±6.5VDC
Internal Power Dissipation ................................. See Thermal Information
Differential Input Voltage .................................................................. ±1.2V
Input Voltage Range ............................................................................ ±VS
Storage Temperature Range: ID, IDBQ ........................ 40°C to +125°C
Lead Temperature (soldering, 10s) .............................................. +300°C
Junction Temperature (TJ ) ........................................................... +175°C
ESD Rating: HBM ............................................................................ 1900V
                   CDM ........................................................................... 1500V


NOTE: (1) Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability.

The OPA3684 provides a new level of performance in low-power, wideband, current-feedback (CFB) amplifiers. This CFBPLUS amplifier among the first to use an internally closed-loop input buffer stage that enhances performance significantly over earlier lowpower CFB amplifiers. While retaining the benefits of very low power operation, this new architecture provides many of the benefits of a more ideal CFB amplifier. The closed-loop input stage buffer gives a very low and linearized impedance path at the inverting input to sense the feedback error current. This improved inverting input impedance retains exceptional bandwidth to much higher gains and improves harmonic distortion over earlier solutions limited by inverting input linearity. Beyond simple high-gain applications, the OPA3684 CFBPLUS amplifier permits the gain setting element to be set with considerable freedom from amplifier bandwidth interaction. This allows frequency response peaking elements to be added, multiple input inverting summing circuits to have greater bandwidth, and low-power line drivers to meet the demanding requirements of studio cameras and broadcast video.

The output capability of the OPA3684 also sets a new mark in performance for low-power current-feedback amplifiers. Delivering a full ±4Vp-p swing on ±5V supplies, the OPA3684 also has the output current to support > ±3Vp-p into 50. This minimal output headroom requirement is complemented by a similar 1.2V input stage headroom giving exceptional capability for single +5V operation. The OPA3684's low 1.7mA/ch supply current is precisely trimmed at 25°C. This trim, along with low shift over temperature and supply voltage, gives a very robust design over a wide range of operating conditions. System power may be further reduced by using the optional disable control pin. Leaving this disable pin open, or holding it HIGH, gives normal operation. If pulled LOW, the OPA3684 supply current drops to less than 100A/ch while the I/O pins go to a high impedance state.