Features

High Bandwidth: 80MHz

High conversion rate: 55V/μs excellent Video performance

0.5DB gain flatness: 25MHz

Differential gain: 0.3%

difference: 0.7 °;

The input range includes ground

Rail output

#8226; Shipping current: lt; 5μA

Low static current: 5.2MA

Single power supply scope:+2.7V to+3.3V

Micro packaging: SC70-6

Digital camera

Phone

Digital media player

Digital camera

Skytop box video filter

[123 ] Light Power Monitor

Cross -blocking large weapon

Automatic testing equipment Explanation [explanation [ 123]

High -speed OPA358 amplifier optimized the 3V single power operation. When the load is connected to GND, the output is usually swinging in the ground 5mv range. The input common modular range includes GND and swinging to the positive power supply 1V. OPA358 has excellent video performance: 0.5DB gain flat flatness is 25MHz, differential gain is 0.3%, and the differential phase is 0.7 °.

The power supply range of OPA358 is+2.7V to+3.3V, and the working range is+2.5V to+3.6V. The static current of each channel is only 5.2mA.

In the shutdown mode, the static current dropped to lt; 5μA, significantly reduced power consumption. This is particularly important in battery power supply equipment, such as digital camera (DSC) or integrated cameraLike a mobile phone.

OPA358 is provided in SC70-6. SC70-6 is currently the smallest software package that can be used for video applications.

OPA358 related products

(1), as shown in the figure, as shown in the figure The direction of the packaging mark is adjusted to determine the pin 1.

Typical features

Unless otherwise explained, all technical specifications are connected to VS/2 when all technical specifications are in TA u003d+25 ° C, RL u003d 150

Application information

working voltage

at 40 Within the temperature range from ° C to+85 ° C, the OPA358 is completely specified as+2.7V to+3.3V. The parameters that significantly change with the working voltage or temperature are displayed in typical features. Power insertion should be bypass with 100NF ceramic capacitors. The input voltage

The input of the input consensus of OPA358 is expanded from (v ) 0.1v to (V+ 1.0V).

Enter overvoltage protection

All OPA358 pins are used in the internal ESD protection diode connected to the power supply for static electricity protection. If the current is limited to 10mA, these diode will provide input -driven protection.

Rail transfers

AB output stage adopts a common source transistor to achieve rail transfers. For 150 load, when the load is connected to VS/2, the output voltage swing is 100MV and 200MV from the negative to the right track, respectively. For lighter loads, while maintaining a high -opening gain, the output is extremely close to the power rail. If the load is grounded, the OPA358 output is usually swinging in the 5mv range of the ground. See the typical characteristic curve, output voltage swing and output current.

Enable/close

OPA358 has a closed function, which can disable the output and reduce the static current to below 5μA. This feature is particularly useful for portable video applications, such as digital cameras (DSC) and camera phones, which are rarely connected to TV or other video devices.

Enable the logic input voltage refer to the OPA358 GND pin. The logic level used to enable the grain to enable the operational amplifier high. Effective logic high level is defined as higher than GND ≥ 1.6V. Low effective logic is defined as higher than GND ≤ 0.8V. If the pin is not connected, the internalThe pull circuit will be enabled to use the amplifier. The effective logic high threshold (minimum 1.6V) and the effective logic low threshold (maximum 0.8V) of the effective logic high threshold (minimum 1.6V).

The enable time is 1.5 μs, and the disable time is only 50ns. This allows the output of OPA358 to be repeated on the public output bus. When disabled, the output assumes a high impedance state.

Video Performance

Industry standard video test mode includes:

Different test frequency Multiple data packets to check the basic frequency response.

Multi -pulse pulse modulated with different frequencies is used to test the comprehensive measurement of the amplitude and group delay error of the video baseband.

color-brightness (CCIR17) -The test amplitude, phase and some distortion. FIG. 2 shows the test circuit of Figure 3 to 13 and FIG. (Note: 1 and 2 represent the measurement point corresponding to the waveforms marked with 1 and 2 in the figure.)

The frequency response of OPA358

The frequency frequency frequency Response measurement and evaluation video system can uniformly transmit the ability of different frequency signals to component different frequency signal components without affecting their respective amplitude. Figure 3 shows the multi -pulse test mode; Figure 4 shows multiple pulses. The top waveform in these figures shows a complete test mode. The middle and bottom waveforms are more detailed views of the key part of the complete waveform. The middle waveform represents the input signal of the video generator; the waveform at the bottom is OPA358 output to the line.

The color of the color and brightness is not equal (or the relative color level) is the color and brightness component of the video signal at different frequencies. Essence The common test mode is the pulse in the test mode CCir17, as shown in Figure 5. As shown in Figure 3 and Figure 4, the top waveform shows a complete test mode. The middle and bottom waveforms are more detailed views of the key part of the complete waveform. The middle waveform represents the input signal of the video generator. The bottom waveform is the OPA358 output to the line.

The gain error usually shows the attenuation or peak of the color information. This is displayed in the picture as incorrect color saturation. Delay distortion can cause blurred or bleeding, especially the edge of objects in the picture. It may also lead to poor reproduction of sharp light transition.

Figure 3 to Figure 5 shows that OPA358 will not cause visible distortion or gain changes in the frequency range of the entire video. output swing to GND (synchronous pulse)

FIGOPA358's output swing capability, it drives input, the synchronous level is 0V. The output of OPA358 is very close to 0V, usually swinging within a range of less than 5mv, and the load ground is 150

Arc Dynamic Correction

The depression school provides excellent video performance through two small output coupling electric containers. It eliminates the traditional, large 220 μF output capacitor. The traditional 220μF circuit (Figure 7A) generates a single low -frequency pole ( 3dB frequency) at 5Hz. If this capacitor is much smaller, excessive phase shifts within the critical range of 50 Hz to 100 Hz will generate the field tilt, which will interfere with the correct recovery of synchronous signals in the TV receiver.

OPA358 (Figure 7B) with depression and correction generates an amplitude response peak in the 20Hz area. The peak (a few of the decibels) of this small part provides compensation for phase response within the critical range of 50 Hz to 100 Hz, which greatly reduces the magnetic field tilt. Please note that there are two obvious and lower -cost capacitors.

The output voltage swing (see Figure 7B) with a calibrated circuit (see Figure 7B) is a function of the coupling electrical value. The value of the curved correction capacitor will only have a small impact. The smaller the coupling capacitor, the larger the output swing. Therefore, in order to adapt to large signal swings in order to use very small coupling capacitors (22 μF and 33 μF), higher power voltage may be required.

DC coupling output

Due to its excellent sway to the ground, OPA358 can also be coupled to the video load. As shown in Figure 8, there is no need to use AC coupling capacitors on the output end. This is especially important in portable video applications limited by the motherboard space.

DC coupling output configuration also shows the best video performance. There is no line or field tilt to allow the minimum power to use. In this mode, OPA358 will work safely to 2.5V without cutting off the signal.

The disadvantage of DC coupling output is that it uses higher power currents.

Broadband video multi -road reuse

A common application of video amplifier (including enable pipe) is to output multiple amplifiers together, and then from several possible video input input Choose which one is input to a line. This simple wired or video multi -road relics can be easily implemented using OPA358, as shown in Figure 9.

capacitance load and stability

OPA358 can drive various capacitance loads. However, under certain conditions, all operational amplifiers may become unstable. The configuration, gain, and load value of the operation amplifier must be considered when determining the stabilitySeveral factors. The computing amplifier of the unit gain structure is most likely to be affected by the capacitor load. The capacitance load and the calculation amplifier output resistance and any additional load resistance react, and generate a pole in the small signal response to reduce the phase margin.

A method of capacitive load driving in the improvement unit gain configuration is to connect a resistor of 10 to 20 #8486 at the output end, as shown in Figure 10. This greatly reduces the bell when the large capacitor load is loaded. However, if there is a resistor load and a capacitor load, RS will generate a divisioner. This will introduce DC errors at the output end and slightly reduce the output swing. This error may be irrelevant. For example, in the case of RL u003d 10K and RS u003d 20 output only about 0.2%of errors.

Broadband span jungler

35 -band -band -boring diode amplifier suitable for low voltage, low noise, low noise input. Low -voltage noise is important because the optical diode capacitance increases the effective noise gain of the circuit at high frequency.

As shown in Figure 11, the key element of cross -resistance design is the expected diode capacitance (including the parasitic input co -mode and differential input capacitors of OPA358 (1.5+1.5) PF, the required cross -resistant gain (RF) and OPA358 (80MHz) gain bandwidth (GBW). After setting these 3 variables, you can set the feedback capacitor value (CF) to control the frequency response.

In order to obtain the largest flat second -order Bartvos frequency response, the feedback pole should be set to:

Typical typical The parasitic capacitance of the surface sticker is about 0.2pf, which must be deducted from the calculated feedback capacitor value.

Bandwidth calculation formula is as follows:

For higher cross -resistance bandwidth, you can use CMOS OPA380 (90MHZGBW), OPA355 (200MHzGBW) or OPA655 (400MHzgbwww (400MHzgbwww) To.