Features

Rail-rail output swing

-3db bandwidth 100MHz

single power supply+5V operation [ 123]

Power dropped to 2.6 Wei'an

Large input co -mode range 0V lt; vcm lt; 3.5V

Differential gain/phase/phase position 0.1%/0.1 °

low power of each amplifier 35mW

SOT33-5, MSOP8 and 10, and QSOP16 packaging

123] Provides lead (in line with RoHS)

Application

Video amplifier

5V analog signal

[

123] Multi -Road Reverandator

Line drive

Portable computer

High -speed communication

sampling and maintaining the amplifier

comparator

100MHz single -electric source rail pairing device

EL5144

series series series series series series series series series series series series series series series series series series series series series series The amplifier is voltage feedback, high -speed, rail -to -rail bars, and designed for working on a single+5V power supply. They provide a stable unit gain and 100 MMS-3 decibel bandwidth. Enter the co -mode voltage range from a negative extension to the 1.5V of the track. Drive the 75Ω dual -end coaxial cable, the EL5144 series amplifier is driven to within 150 millivolochia. The conversion rate of 200V/microsecond and the differential gain/differential phase of the differential gain/difference of 0.1%/0.1 ° make these components very suitable for composite and component video applications. Using its voltage feedback structure, these amplifiers can accept non -contribution feedback networks, allowing them to simulate filtering and apply these amplifiers to the source 90mA and Hui 65mA.

EL5146

and EL5246 have energy -saving disability. Apply the standard TTL low -logic level to CE (chip enable) pins can be reduced in 10ns to 2.6 Weire. The opening time is 500ns, allowing real interruptions before creating conditions for multi -way reuse applications. Allowing CE pin floating or application high -logo levels will be enabled to use the amplifier. For the vital application of the circuit board space, the single chip is encapsulated with 5 stitches SOT-23, the dual chip is encapsulated with 8 stitches and 10-pin MSOP, and the four-chip is encapsulated by 16-pin QSOP. Single core, dual core and four coresCan be used for industrial standards in SO and PDIP packaging. All components work within the industrial temperature range of -40 ° C to+85 ° C.

pinouts

Typical performance curve

123] Operation and application information description Product description

EL5144 series is a series Voltage feedback computing amplifier. This series includes single, double and four configurations. Both the single and the bilateral have a power descending pipe foot, which usually reduces the power to 2.6 Weian. The internal compensation closed -loop feedback gain of all amplifiers is +1 or larger. Larger gains are acceptable, but according to the GainBandWidth products we are familiar with, bandwidth will be reduced.

The EL5144 series adopts a voltage follow-up mode connection, drives high impedance load, the bandwidth is -3DB, 100MHz. When driving the 150Ω load, they have a 60-meter-3 decibel bandwidth, while maintaining a conversion rate of 200 volts/microseconds. The input co -mode voltage range includes grounding, and the output end can swing between the rails.

Power bypass and printing circuit board layout

Like any high -frequency device, a good printing circuit board layout is a necessary condition for gaining the best performance. It is strongly recommended to carry out ground flooring. The length of the lead should be as short as possible. In order to reduce the oscillating risk of normal single power supply, it is necessary to completely bypass the power of the power supply. In the case of the ground pins connected to the ground plane, a 4.7μF 钽 capacitor is connected with a 0.1 μF ceramic capacitor (from V to GND) parallel. enough. If you want to use a split power supply, the same capacitor should be placed at each ground power supply. In this case, ground pins have become negative power rails.

In order to obtain good communication performance, parasitic capacitors should be maintained at the minimum value. Avoid using a wire wound, because they have extra series inductance. If possible, avoid using sockets, especially SO packs. The socket increases parasitic inductance and capacitance, which may cause performance damage.

Input, output and power supply voltage range

The EL5144 series is designed as a single power supply voltage of 5 volts. As long as the total range is 5 volts, the split power can be used.

The amplifier has an input co -mode voltage range, including negative power supply (GND pins), and extends to the 1.5V range of the positive power supply (VS pin). They are specified within this range.

The output of the EL5144 series amplifier can achieve the rail on the rail on the rail. As the load resistance value decreases, the driving capacity of each track decreasesEssence However, even if there is an effective 150Ω load resistor connected to the intermediate voltage between the power rail, the output will swing within the 150 millival of any orbit.

FIG. 1 shows the output of the EL5144 series amplifier in the case of RF 1kΩ, AV +2, and RL 1MΩ. Figure 2 shows RL 150Ω.

Selected F -type F -type

These amplifiers optimized for applications that need +1 gain. Therefore, no feedback resistance is required. However, for gains greater than +1, the feedback resistance and input capacitance formation is extremely extremely. When the magnetic pole becomes larger, the phase margin decreases. This will cause bells in the time domain and cause peaks in the frequency domain. Therefore, R has some maximum values and should not exceed this value to obtain the best performance. If a larger R value must be used, the small electric container in the small pickup range of the R -parallel Rifhara can help reduce this bell and peak, but the cost is to reduce the bandwidth.

As far as the output level of the amplifier is concerned, for the gains other than +1, R+R and R are parallel. When this combination changes, the bandwidth will decrease. Therefore, R also has a minimum value. In order to get the best performance, it should not exceed this value.

For A +1, R 0Ω is the best value. For A -1 or +2 (noise gain is 2), the best response is obtained when R is between 300Ω and 1kΩ. For A -4 or +5 (noise gain is 5), keep RF between 300Ω and 15kΩ.

Video performance

In order to obtain a good video signal integrity, the amplifier needs to maintain the same output impedance and the same frequency response because the DC level changes at the output end. When driving a 150 ohm, because the output current changes with the DC level. Viewing differential gains and differential phase curves under different power supply and load conditions will help get the best performance. A curve of AV +1 and +2, RL 150Ω and 10kΩ are connected to the ground and 2.5V. Like all video amplifiers, there is the best point of common models with the optimal difference in differences/differential phases. For example, when AV +2 and RL 150Ω are binded to 2.5V, and the output co -mode voltage is kept between 0.8V and 3.2V, the DG/DP is 0.1%/0.1 ° of non -normal low. This condition corresponds to the driving AC coupling and the two -terminal 75Ω coaxial cable. When AV +1, RL 150Ω ground, and the video level remains between 0.85V and 2.95V, these amplifiers provide 0.05%/0.20 ° DG/DP performance. This situation represents the use of the EL5144 series amplifier as a buffer driver DC coupling, two -terminal connection, and 75Ω coaxial cable. Drive high impedance load (such as signals on a computer video card) can provide similar or better DG/DP performance similar to the driver cable.

Drive cable and capacitor load

EL5144 series amplifier can drive 50PF load, with a peak of 4DB 150Ω and 100PF with a peak of 7DB. If you need less peaks in these applications, a small series resistance (usually between 5Ω and 50Ω) can be connected with the output to eliminate most of the peak values. However, this will obviously reduce the gain slightly. If your gain is greater than 1, you can choose the gain resistor (R) to compensate for any gain loss of the additional resistor at the output end. Another way to reduce the peak value is to add a buffer circuit to the output end. The buffer circuit is a series resistance, the capacitor 150Ω and 100pf are typical values. The advantage of the buffer circuit is that it does not generate DC load current.

When used as a cable drive, it is recommended to use two -terminal connection to achieve non -reflection performance. For these applications, the back -end stringor resistor will be separated from the cable EL5144 series amplifier and allows a wide range of capacitors to drive. However, other applications may have high -capacitance loads and no rear resistance. Similarly, the small string of connected resistance on the output end can reduce its peak.

Disable/shutdown

EL5146 and EL5246 amplifier can be disabled, so that its output is in a high impedance state. The shutdown time is only 10ns, and the boot time is about 500ns. When disabled, the power current of the amplifier often decreases to 2.6 Weire, thereby effectively eliminating power consumption. The power decrease of the amplifier can be controlled by the standard TTL or CMOS signal level in the CE pin. The logic signal of the application is related to the ground pins. Let the CE pin float will enable the amplifier. Therefore, the 8 -pin PDIP and SOIC Shan'anpei is a standard amplifier with compatible pins and has no power loss function.

Short -circuit current limit

EL5144 series amplifier does not have internal short -circuit protection circuits. If the output is attempt to drive high or low, but the short circuit between the tracks, the short -circuit currents of 90 mAh and 65 mAh depressions often flow. If the output is short -term, the power consumption is easy to increase, which will damage the part. If the output current does not exceed ± 50mA, it remains to the maximum reliability. This limit is set up by internal metal interconnection restrictions. Obviously, short -circuit conditions cannot be maintained, otherwise the internal metal connection will be destroyed.

Power consumption

Due to the high output driving capacity of the EL5144 series amplifier, under certain load current conditions, it may exceed 150 ° C with absolute maximum temperature. Therefore, the maximum temperature of the computing application is important for determining whether the amplifier needs to modify the load conditions or the type of packaging to maintain it in a safe working area.

The maximum power consumption allowed in the package is determined according to the following conditions:

In the formula: tjmax the highest knot temperature

tamax the highest Environmental temperature

θja Thermal resistance of packaging

PDmax Maximum power consumption in packaging

The actual maximum power consumption of the integrated circuit is the total static power supply current multiply at the total power supply, plus the power generated by the load in the integrated circuit, or: [123 123 ]

In the formula: N Number of amplifiers in the package

vs total power supply voltage

ISMAX Maximum power supply current of each amplifier [ 123]

VOUT Maximum output voltage of the application

RL ground load resistance

If we equal these two PDMAX equations with each other, we can solve RL:

[123 123 ]

Assuming the worst case of TA +85 ° C, the V V/2V, V 5.5V and I 8.8ma of each amplifier, the following is the minimum packaging and allowable minimum to be encapsulated and allowed RL's table.

The application of the compaper of the EL5144 series

EL5144 series amplifier can be used as a very fast single power comparator. Due to the output saturation problem, most of the comparator operation amplifier can only allow low speeds to run. The EL5144 series amplifier does not have the problem of output saturation. Figure 3 shows the amplifier implemented as a comparator. FIG. 4 is a diagram of the delay and passing drive when the comparator input is presented.

and the EL5144 series amplifier multi -road

In addition Road repeat application. Figure 5 shows an EL5246, which is connected together to drive a 75Ω back -end video load. A 3V 10MHz sine wave is applied to the amplifier A input terminal, and a 2.4V 5MHz square wave is applied to the B -end of the amplifier. Figure 6 shows the selection signal applied, and the output waveform generated under V. Observe the interruption before performing multi -way reuse operations. The amplifier A is opened, V is out of the amplifier. Then the amplifier A is closed after about 10 ns. The output is attenuated to the ground with the RLCL time constant. After 500ns, AMP B is opened and vin2 is passed to the output end. This kind of break -down operation ensures that more than one amplifier will not try to drive the bus at the same time. Note that the output is directly binded together. Each output does not require isolation resistance.

Self -exciting oscillator application

FIG. 7 is an EL5144 configured to freely run the oscillator.

For first -order, R and C determine the oscillating frequency based on the following formulas:

For rail -to -orbit output oscillation, the maximum oscillation frequency is about 15mhhz.If you can accept a reduced output width, you can reach 25MHz.Figure 8 shows ROSC 510Ω, COSC 240pf and FOSC 6MHz.