Features

Wide power supply range: ± 4 v to ± 30 v

High output current: 200 mA continuous

#8226; Low noise: 14 nv/√Hz

Complete protection:

- Hot shutdown

- Limited output current

hot shutdown indicator

Wide output swing: Follow orbit 2 v

Quick conversion rate:

--Pa551:: 15 volts/microseconds

—OPA552: 24 volts/microseconds

Broadband:

—OPA551: 3 MPA : 12 MMH

Packaging: PDIP-8, SOIC-8 or DDPAK/TO-263-7

Tel [123 ]

Test equipment

Audio amplifier

sensor excitation

servo drive

[

123] Explanation

OPA551X device is a low-cost computing amplifier, which has high voltage (60-V) and large current (200 mAh) capabilities.

OPA551 is a stable unit gain and has a high conversion rate (15V/μS) and broad band width (3MHz). The optimized gain of OPA552 is 5 or higher, and it provides a higher speed. The conversion rate is 24V/μ bandwidth to 12MHz. Suitable for audio and servo devices.

These laser fine -tuning, single -piece integrated circuit provides excellent low level accuracy and high output swing. When the amplifier swings to the specified limit, it can still maintain high performance.

OPA55X equipment has internal protection, which can prevent overheating conditions and current overload heat shutdown indicators to provide current output, reminding users when heat shutdown occurs.

OPA55X devices include PDIP-8 and SOIC-8 packaging, and DDPAK-7/To-263 surface sticker plastic power pack. They are suitable for running within the range of industrial temperature range (-40 ° C to+125 ° C).

Equipment information

(1), please refer to the appointment appendix at the end of the data table.123]

Simplified function map

Typical features

TJ u003d 25 ° C, vs u003d ± 30 v, rl u003d 3 kΩ, unless unless Another explanation.

Detailed explanation Overview ] OPA55X device is a low -cost, laser fine -tuning computing amplifier, which has the characteristics of outstanding low level accuracy and high output swing. In extensive applications, when these amplifiers swing to the specified device limit, they can still maintain high device performance. OPA551 is a stable unit gain, while OPA552 is the optimized gain of 5 or larger. Function box diagram

Feature description

heat shutdown

Internal heat shutdown circuit at the mold temperature reached about 160 ° reaching approximately 160 ° Turn out the output when C, and reset when the mold cools to 140 ° C. You can monitor the signs to determine whether to shut down. During normal work, the current source from the signs pin is less than 50 mAh. During the shutdown, the power supply of the signs is 120 μA (typical).

current limit

OPA55X device design has an internal current limit circuit, which limits the output current to about 380 mAh. The current limit changes with the increase of the edge temperature, as shown in Figure 11. This function is combined with thermal protection circuit, which can provide a variety of overload protection, including short -circuit on the ground.

Input protection

OPA55X uses an internal clamp diode to protect the input when the voltage exceeds the power rail. However, the input current must be limited to 5 millions. In some cases, external series resistors may be needed. Many input signals have inherent current limit; therefore, the resistor may not be required. Considering a large series resistance, plus input capacitance, it will affect stability.

Heat protection

OPA55X has a heat clearance circuit, which can protect the amplifier from damage caused by overload. When the knot temperature reaches about 160 ° C, the thermal protection circuit will be disabled and the equipment will cool down. When the knot temperature is cooled to about 140 ° C, the output circuit will be automatically enabled.

The heat clearance function is not used to replace appropriate heat dissipation. The activation of the heat shutdown circuit indicates that the power consumption is too large or the heat sink is insufficient. Continuous operation amplifiers enter the heat shutdown state to reduce reliability.

Monitor the heating shutdown indicator (logo) pin to determine whether to stop. During the normal operation, the current output of the signs pins is usually 50 mAh. During the shutdown, the current output from the signs pin increases to 120μA (typical value). This current output allows connecting with external logic. For two examples of implementing this function, see Figure 25 and Figure 26.

HCT logic has a good level of logic control. A correct selected resistance value can ensure the logical high level within the range of the entire flag output current.

By selecting the resistance value and almost any CMOS logical door interface, the resistance value provides a guaranteed logical high voltage and minimum (80 μA) logo current. The diodes of the logical power supply voltage ensure that the CMOS is not damaged due to excessive drive.

Equipment function mode

OPA551 and OPA552 have a single function mode. When the power supply voltage is higher than 8V and the knot temperature is lower than 160 ° C, the device can work.

Application and implementation

Note: The information in the following application chapters is not part of the TI component specification, TI does not guarantee its accuracy or integrity. TI's customers are responsible for determining the applicability of the component. Customers should verify and test their design implementation to confirm the system function.

Application information

FIG. 27 shows OPA551 as a basic non -conversion amplifier connection. OPA551 can be used for almost any computing amplifier configuration. OPA552 design is used for configuration with gain greater than or equal to 5. The power terminal must be bypassed with 0.1-μF or larger capacitors near the power of the power supply. Ensure that the rated value of the capacitor matches the voltage of the power supply. OPA55X can provide an output current of up to 200 mA, with excellent performance.

Typical application

run under the power supply of ± 15 v to ± 30 V

Drive the passive and non -merit load of 1A

Drive the large capacitance load

the operating temperature is as high as 125 ° C

Detailed design program

Capacity load

The dynamic characteristics of OPA55X have been optimized for common gain, load and operating conditions. The binding of low -closed cycle gain and capacitance load reduces phase margin, and may lead to peak or oscillation of gain. FIG. 28 shows a circuit that maintains phase margin under the 10NF capacitor load. Figure 33 shows the small signal step response of the circuit in Figure 28. For more information, please consult SBOA015.

Increase the output current

The output current in those 200 mAh is not enoughIn the application required by the driver, the output current can be increased by connecting two or more OPA551 or OPA552s in parallel, as shown in Figure 29. The amplifier A1 is the main amplifier, which can actually be configured in the operation amplifier circuit. From the amplifier A2 to the unit gain buffer. Alternatively, you can use an external output transistor to increase the output current. The circuit in FIG. 30 can provide an output current up to 1A. Alternatively, consider OPA547, OPA548, and OPA549 series power computing amplifiers for high output current drivers, as well as programmable current restrictions and output disable functions.

Use OPA552

OPA552 series in low -gain applications for signal gain to 5 or higher applications, but can be configured in the inverter configuration Use external compensation technology to use high conversion rates in low gain. This technology maintains the low noise characteristics of the OPA552 architecture at low frequency. According to the application, it may lead to a small increase in high -frequency noise. This technology has shaped the circuit gain to obtain good stability, and at the same time provides a second -order low -line frequency response that is easy to control.

Only the noise gain (non -reversal signal gain) of the circuit in Figure 31, low -frequency noise gain (NG1) set from a resistance ratio, while high -frequency noise gain (NG2) is set by a capacitor ratio. The capacitor value sets the transition frequency and high -frequency noise gain. If the noise gain determined by NG2 u003d 1+CS/CF is set to the recommended minimum stable gain value greater than the computing amplifier, and the noise gain set by 1/RFCF is polarized, it will produce a very good control two two Low -pass frequency response.

To select the values u200bu200bof CS and CF at the same time, two parameters and three equations must be solved. First, the goal of high -frequency noise gain (NG2) must be greater than the minimum stable gain of OPA552. In the circuit shown in FIG. 31, the target NG2 is 10. Secondly, the signal gain shown in FIG. 31 -1 Set low-frequency noise gain to NG1 u003d 1+RF/RG (u003d in this example 2). With these two gains, know the gain bandwidth (GBP) of OPA552 (12MHz), and aim at the maximum flat second -order low -pass Bartworth frequency response (Q u003d 0.707), you can find the key frequency in compensation.

For the value shown in FIG. 31, the F -3DB is about 956 kHz. This frequency is smaller than the frequency predicted by NG1 with the British pound. The compensation network controls the bandwidth to a lower value, and at the same time provides a full conversion rate at the output end, and because the loop gain is increased at the frequency of NG1 × Z0, it has excellent distortion performance. The capacitance value shown in FIG. 31 is calculated for ng1 u003d 2 and ng2 u003d 10, and there is no need to adjust the parasitic.

By checking the small signal step response under the actual load conditions,Optimize the actual circuit value. Figure 32 shows the small signal level response of the OPA552, G u003d -1 circuit under 500 PF load. It is healthy and has no oscillation trend. If CS and CF are removed, the circuit will become unstable.

The offset voltage error calculation

The offset voltage (VOS) of OPA51 and OPA552 consists of the common mold voltage between ± 30 V power and power supply ( Vs/2 u003d 0 v) regulations. Provides additional specifications for power suppression and co -modular suppression to allow users to easily calculate the worst situation under the conditions of given application conditions.

Power suppression ratio (PSRR) is represented by μV/V. For OPA55X, the worst PSRR is 30 μV/V, which means that for every voltage change of the total power supply voltage, the offset can be offset by up to 30 μV/V. The co -model suppression ratio (CMRR) is in DB, and the Formula 1 can be converted to μV/V:

(1)

For OPA55X, the entire co -mode range is in the entire co -mode range Under the power condition of ± 30 MV, the worst CMRR is 96 dB, or about 15.8 μV/V. This result means that every time the co -mode changes the voltage, the offset can be offset by up to 15.8 μV. These numbers can be used to calculate the offset of specified offset voltage under different application conditions. For example, a common application may configure the amplifier to a -48 volt power supply and -6 volt model power supply. This configuration represents the 12 volt changes of the power supply: the offset specification is ± 30 volts or 60 volts, and the application is 48 volts. In addition, the co -mode voltage of this configuration changes to 18 volts: VS/2 u003d - 24 il is the specifications of these power supply, but the CCP voltage is -6 voltage in the application of the Communist Party of China.

In this case, the calculation of the expected offset in the worst case is calculated by formula 2 and formula 3.

Application curve

FIG. 33 shows the small signal step response of the circuit in Figure 28. For more information, please consult AB-028.

Power suggestion

Power supply

OPA55X can work at a power supply under the power supply with ± 4 v to ± 30 V or a total voltage of 60 V And good performance. Without the entire working voltage range, most characteristics remain unchanged. It shows the typical feature of the parameter that changes significantly with the working voltage.

For applications that do not require symmetrical output voltage, the power supply voltage does not require equal. OPA55X can work when the voltage between the power supply is as low as 60 volts between 8 volts or the power supply is as high as 60 volts. For example, the positive power supply can be set to 50 V, and the negative power supply is set to -10 V, and vice versa.

SOIC-8 packaging shape shows three negative power (V-) pin. These pins are connected inside to improve thermal performance.

Note

Pin pin 4 must be used as the main carrier of the negative power supply. It is recommended not to connect to V -Point 1 and 5 directly to V -. Instead, connect the needle 1 and 5 to the thermal quality. Do not arrange the printing circuit board (PCB) to use the pins 1 and 5 as the lead of the negative electrode power supply. Such configuration can cause performance reduction.

DDPAK/TO-263 The convex ears packaged with the negative electrode power supply (V-) electricity. However, this connection must not be used for loading. In order to obtain the best thermal performance, the convex ear is directly welded to the PCB copper area (see the heat dissipation part).

Layout

Layout Guide

The circuit board must have as many floor area as possible. The size of the power supply and output trajectory must be able to process the required current. As much as possible to separate the input and output terminals.

layout example

Power consumption

The internal power consumption of these operational amplifiers may be quite large. Many specifications of OPA55X are targeted at specific knot temperature. If the device is not heated internally, the knot temperature is the same as the environmental temperature. However, in practical applications, the device is spontaneous, and the knot temperature is significantly higher than the ambient temperature. After determining the knot temperature, the performance parameters of the conjunction temperature can be determined according to the performance curve. The following calculations can be performed to determine that the knot temperature is a function of the ambient temperature and application conditions.

In the circuit configuration of a load of 600Ω and the output voltage is 15 V, consider OPA551. The power supply voltage is ± 30 V, and the ambient temperature (TA) is 40 ° C. The θJa package package packaged at 8 is 100 ° C/W.

First of all, the internal heating of the operation amplifier is shown in the same formula 4:

(4)

Output current (IO) can be calculated in Formula 5:

(5)

The power dissipation (PD) in the amplifier output transistor can be calculated in equal 6 and equations 7:

[

[ 123] The resulting temperature can be calculated in the formula 8 and type 9:

In the formula:

tj; tj u003d Joint temperature (° C)

ta u003d ambient temperature (° C)

θja u003d connect to air thermal resistance (° C/w) [ 123] For DDPAK/TO-263 packaging, θJa is 65 ° C/W, no heat dissipation, and the knot temperature is 92.5 ° C.

To estimate the safe waste of the complete design (including the radiator), increase the ambient temperature until the heat protection activation. Use the load and signal conditions in the worst case. In order to obtain good reliability, thermal protection must trigger a temperature with a maximum expected environmental condition above the given application above 35 ° C. This limit can ensure that the maximum knot temperature under maximum expected environmental conditions is 125 ° C.

If OPA551 or OPA552 is used to apply more than 0.5W continuous power consumption, TI is recommended to use DDPAK/To-263 packaging options. DDPAK/TO-263 has superior heat dissipation characteristics and is easier to adapt to the radiator.

The operation of a single power supply (or unbalanced power supply) can generate greater power consumption because a larger voltage can be applied to the electrical output transistor. For more information about how to calculate or measure power consumption, please consult SBOA022.

By using as low as possible, the power consumption can be minimized. For example, when the load is 200 mAh, the output voltage is within 3.5 volts of the power rail. Set the power supply to the maximum output voltage required for the application 3.5 V to minimize the power consumption.

Security Operation Area

The Safety Operation Area (SOA) curve graph 35, Figure 36, and Figure 37 show the allowable range of voltage and current. These curves show device welded to the circuit board without heat sinks. When the voltage (VS -VO) on the output transistor increases, the safe output current decreases. For more information about SOA, please consult AB-039.

The output short circuit is a very harsh situation for SOA. The short-circuit of the ground forced the entire power supply voltage (V+or V-) through the conductive transistor and generated a typical output current of 380 mA. For ± 30-V power, this configuration can generate an internal power of 11.4 W. This power consumption far exceeds the maximum rated value and is not recommended. If you must operate in this area, use DDPAK/To-263 packaging with a heat sink.

Heating

The power consumed in OPA551 or OPA552 causes the knot temperature to rise. To ensure reliable operation, the knot temperature is limited to 125 ° C. Many applications require radiator to ensure that it will not exceed the highest work knot temperature. The required heat sink depends on power consumption and environmental conditions.

In order to heat dissipation, the convex ear of DDPAK/To-263 is usually directly welded to the PCB copper area. Increased copper area can improve heat dissipation. Figure 38 shows the relationship between typical thermal resistance and copper area from the connection to the surrounding environment.

Additional sinking conditions may be needed. AAVID Thermal Products Inc. Manufacturing surface paste consumption radiator, specially used for DDPAK/TO-263 package.

It is necessary to estimate the safe balance of the complete design (including the radiator), please increase the ambient temperature until the heat protection activation.Use the load and signal conditions in the worst case.In order to obtain good reliability, thermal protection must trigger a temperature above the maximum expected environmental conditions above the application of 25 ° C.Under the maximum expected environmental conditions, this level generates a 125 ° C knot temperature.

Machinery, packaging and ordering information

The following page includes machinery, packaging and ordering information.This information is the latest data available for specified devices.If this data is changed, it will not be notified or modified.For the version of this data table based on the browser, see the left side navigation.