Electronic Components Datasheet Search |
|
OPA551 Datasheet(PDF) 10 Page - Texas Instruments |
|
|
OPA551 Datasheet(HTML) 10 Page - Texas Instruments |
10 / 24 page OPA551, OPA552 10 SBOS100A www.ti.com POWER SUPPLIES The OPA551 and OPA552 may be operated from power supplies of ±4V to ±30V, or a total of 60V with excellent performance. Most behavior remains unchanged throughout the full operating voltage range. Parameters that vary sig- nificantly with operating voltage are shown in the Typical Performance Curves. For applications that do not require symmetrical output voltage swing, power supply voltages do not need to be equal. The OPA551 and OPA552 can operate with as little as 8V between the supplies or with up to 60V between the supplies. For example, the positive supply could be set to 50V with the negative supply at –10V or vice-versa. The SO-8 package outline shows three negative supply (V–) pins. These pins are internally connected for improved thermal performance. Pin 4 is to be used as the primary current carrier for the negative supply. It is recommended that pins 1 and 5 not be directly connected to V– but, instead be connected to a thermal mass. DO NOT lay out the PC board to use pins 1 and 5 as feedthroughs to the negative supply. Doing so can result in a reduction of performance. The tab of the DDPAK-7 package is electrically connected to the negative supply (V–), however, this connection should not be used to carry current. For best thermal performance, the tab should be soldered directly to the circuit board copper area (see heat sink text). POWER DISSIPATION Internal power dissipation of these op amps can be quite large. Many of the specifications for the OPA551 and OPA552 are for a specified junction temperature. If the device is not subjected to internal self-heating, the junction temperature will be the same as the ambient. However, in practical applications, the device will self-heat and the junc- tion temperature will be significantly higher than ambient. After junction temperature has been established, perfor- mance parameters that vary with junction temperature can be determined from the performance curves. The following calculation can be performed to establish junction tempera- ture as a function of ambient temperature and the conditions of the application. Consider the OPA551 in a circuit configuration where the load is 600 Ω and the output voltage is 15V. The supplies are at ±30V and the ambient temperature (T A) is 40°C. The θJA for the 8-pin DIP package is 100 °C/W. First, the internal heating of the op amp is as follows: PD(internal) = IQ • VS = 7.2mA • 60V = 432mW The output current (IO) can be calculated: IO = VOUT/RL = 15V/600Ω = 25mA The power being dissipated (PD) in the output transistor of the amplifier can be calculated: PD(output stage) = IO • (VS – VO) = 25mA • (30 – 15) = 375mW PD(total) = PD(internal) + PD(outputstage) = 432mW + 375mW = 807mW The resulting junction temperature can be calculated: TJ = TA + PD θJA TJ = 40°C + 807mW • 100°C/W = 120.7°C Where, TJ = junction temperature (°C) TA = ambient temperature (°C) θ JA = junction-to-air thermal resistance (°C/W) For the DDPAK package, the θ JA is 65°C/W with no heat sinking, resulting in a junction temperature of 92.5 °C. To estimate the margin of safety in a complete design (including heat sink), increase the ambient temperature until the thermal protection is activated. Use worst-case load and signal conditions. For good reliability, the thermal protec- tion should trigger more than +35 °C above the maximum expected ambient condition of your application. This en- sures a maximum junction temperature of +125 °C at the maximum expected ambient condition. If the OPA551 or OPA552 is to be used in an application requiring more than 0.5W continuous power dissipation, it is recommended that the DDPAK package option be used. The DDPAK has superior thermal dissipation characteris- tics and is more easily adapted to a heat sink. Operation from a single power supply (or unbalanced power supplies) can produce even larger power dissipation since a larger voltage can be impressed across the conducting output transistor. Consult Application Bulletin AB-039 for further information on how to calculate or measure power dissipation. Power dissipation can be minimized by using the lowest possible supply voltage. For example, with a 200mA load, the output will swing to within 3.5V of the power supply rails. Power supplies set to no more than 3.5V above the maximum output voltage swing required by the application will minimize the power dissipation. SAFE OPERATING AREA The Safe Operating Area (SOA curves, Figures 3, 4, and 5) shows the permissible range of voltage and current. The curves shown represent devices soldered to a circuit board with no heat sink. The safe output current decreases as the voltage across the output transistor (VS – VO) increases. For further insight on SOA, consult Application Bulletin AB-039. Output short circuits are a very demanding case for SOA. A short circuit to ground forces the full power supply voltage (V+ or V–) across the conducting transistor and produces a typical output current of 380mA. With ±30V |
Similar Part No. - OPA551 |
|
Similar Description - OPA551 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |