công cụ tìm kiếm bảng dữ liệu linh kiện điện tử |
|
LM1086-ADJMDC bảng dữ liệu(PDF) 11 Page - Texas Instruments |
|
|
LM1086-ADJMDC bảng dữ liệu(HTML) 11 Page - Texas Instruments |
11 / 23 page 11 LM1086-MIL www.ti.com SNVSAX4 – JUNE 2017 Product Folder Links: LM1086-MIL Submit Documentation Feedback Copyright © 2017, Texas Instruments Incorporated Feature Description (continued) 7.3.3 Overload Recovery Overload recovery refers to the ability of the regulator to recover from a short-circuited output. A key factor in the recovery process is the current limiting used to protect the output from drawing too much power. The current- limiting circuit reduces the output current as the input-to-output differential increases. Refer to short-circuit curve in Typical Characteristics. During normal start-up, the input-to-output differential is small because the output follows the input. But, if the output is shorted, then the recovery involves a large input to output differential. Sometimes during this condition the current limiting circuit is slow in recovering. If the limited current is too low to develop a voltage at the output, the voltage will stabilize at a lower level. Under these conditions it may be necessary to recycle the power of the regulator in order to get the smaller differential voltage and thus adequate start up conditions. Refer to Typical Characteristics for the short circuit current vs input differential voltage. 7.4 Device Functional Modes 7.4.1 Output Voltage The LM1086-MIL adjustable version develops a 1.25-V reference voltage, (VREF), between the output and the ADJ pin. As shown in Figure 16, this voltage is applied across resistor R1 to generate a constant current I1. This constant current then flows through R2. The resulting voltage drop across R2 adds to the reference voltage to sets the desired output voltage. The current IADJ from the adjustment terminal introduces an output error . But since it is small (120 µA maximum), it becomes negligible when R1 is in the 100- Ω range. For fixed voltage devices, R1 and R2 are integrated inside the devices. Figure 16. Basic Adjustable Regulator 7.4.2 Stability Consideration Stability consideration primarily concerns the phase response of the feedback loop. In order for stable operation, the loop must maintain negative feedback. The LM1086-MIL requires a certain amount series resistance with capacitive loads. This series resistance introduces a zero within the loop to increase phase margin and thus increase stability. The equivalent series resistance (ESR) of solid tantalum or aluminum electrolytic capacitors is used to provide the appropriate zero (approximately 500 kHz). Aluminum electrolytics are less expensive than tantalum capacitors, but their ESR varies exponentially at cold temperatures requiring close examination when choosing the desired transient response over temperature. Tantalums are a convenient choice because their ESR varies less than 2:1 over temperature. The recommended load/decoupling capacitance is a 10-µF tantalum or a 50-µF aluminum. These values assure stability for the majority of applications. The adjustable versions allows an additional capacitor to be used at the ADJ pin to increase ripple rejection. If this is done increate the output capacitor to 22 µF for tantalum or to 150 µF for aluminum. Capacitors other than tantalum or aluminum can be used at the adjust pin and the input pin. A 10-µF capacitor is a reasonable value at the input. See Ripple Rejection regarding the value for the ADJ pin capacitor. |
Số phần tương tự - LM1086-ADJMDC |
|
Mô tả tương tự - LM1086-ADJMDC |
|
|
Link URL |
Chính sách bảo mật |
ALLDATASHEET.VN |
Cho đến nay ALLDATASHEET có giúp ích cho doanh nghiệp của bạn hay không? [ DONATE ] |
Alldatasheet là | Quảng cáo | Liên lạc với chúng tôi | Chính sách bảo mật | Trao đổi link | Tìm kiếm theo nhà sản xuất 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 |