Electronic Components Datasheet Search |
|
OPA549 Datasheet(PDF) 9 Page - Burr-Brown (TI) |
|
|
OPA549 Datasheet(HTML) 9 Page - Burr-Brown (TI) |
9 / 14 page ® 9 OPA549 FIGURE 2. Adjustable Current Limit. ENABLE/STATUS (E/S) PIN The Enable/Status Pin provides two unique functions: 1) output disable by forcing the pin low and 2) thermal shutdown indication by monitoring the voltage level at the pin. Either or both of these functions can be utilized in an application. For normal operation (output enabled), the E/S pin can be left open or driven high (at least 2.4V above Ref). A small value capacitor connected between the E/S pin and CREF may be required for noisy applications. Output Disable To disable the output, the E/S pin is pulled to a logic low (no greater than 0.8V above Ref). Typically the output is shut down in 1 µs. To return the output to an enabled state, the E/S pin should be disconnected (open) or pulled to at least 2.4V above Ref. It should be noted that driving the E/ S pin high (output enabled) does not defeat internal ther- mal shutdown; however, it does prevent the user from monitoring the thermal shutdown status. See Figure 3 for an example implementing this function. This function not only conserves power during idle periods (quiescent current drops to approximately 6mA) but also allows multiplexing in multi-channel applications. Figure 12 shows two OPA549s in a switched amplifier configuration. The on/off state of the two amplifiers is controlled by the voltage on the E/S pin. Under these conditions, the disabled device will behave like a 750pF load. Slewing faster than 3V/ µs will cause leakage current to rapidly increase in devices that are disabled, and will contribute additional load. At high temperature (125 °C), the slewing threshold drops to approximately 2V/ µs. Input signals must be limited to avoid excessive slewing in multiplexed applications. FIGURE 3. Output Disable. OPA549 E/S CMOS or TTL Ref Logic Ground 7500 Ω R CL 0.01 µF (optional, for noisy environments) 8 6 8 6 4.75V R CL = – 7500 Ω OPA549 CURRENT LIMIT: 0A to 10A NOTES: (1) Resistors are nearest standard 1% values. (2) Offset in the current limit circuitry may introduce approximately ±0.25A variation at low current limit values. DESIRED CURRENT LIMIT 0A(2) 2.5A 3A 4A 5A 6A 7A 8A 9A 10A RESISTOR(1) (R CL) I LIM Open 22.6k Ω 17.4k Ω 11.3k Ω 7.5k Ω 4.99k Ω 3.24k Ω 1.87k Ω 845 Ω I LIM Connected to Ref CURRENT (I SET) 0 µA 158 µA 190 µA 253 µA 316 µA 380 µA 443 µA 506 µA 570 µA 633 µA VOLTAGE (V SET) (Ref) + 4.75V (Ref) + 3.56V (Ref) + 3.33V (Ref) + 2.85V (Ref) + 2.38V (Ref) + 1.90V (Ref) + 1.43V (Ref) + 0.95V (Ref) + 0.48V (Ref) (a) RESISTOR METHOD 15800 (4.75V) I LIM = – 7.5k Ω 75k Ω I LIM 7500 Ω I SET = ILIM/15800 V SET = (Ref) + 4.75V – (7500Ω) (ILIM)/15800 (b) DAC METHOD (Current or Voltage) D/A I SET 4.75V Ref Ref ±I LIM = Max I O = ILIM (4.75) (15800) 7500 Ω + R CL Max I O = ILIM ±I LIM =15800 ISET |
Similar Part No. - OPA549 |
|
Similar Description - OPA549 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | 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 |