công cụ tìm kiếm bảng dữ liệu linh kiện điện tử |
|
LM397 bảng dữ liệu(PDF) 5 Page - Texas Instruments |
|
|
LM397 bảng dữ liệu(HTML) 5 Page - Texas Instruments |
5 / 15 page VOLTS VREF VO TIME VIN VREF VIN VO - + V - RPULL-UP VS LM397 www.ti.com SNOS977D – MAY 2001 – REVISED MARCH 2013 APPLICATION NOTES Basic Comparators A comparator is quite often used to convert an analog signal to a digital signal. The comparator compares an input voltage (VIN) at the non-inverting pin to the reference voltage (VREF) at the inverting pin. If VIN is less than VREF the output (VO) is low (VOL). However, if VIN is greater than VREF, the output voltage (VO) is high (VOH). Refer to Figure 9. Figure 9. Basic Comparator Hysteresis The basic comparator configuration may oscillate or produce a noisy output if the applied differential input is near the comparator’s input offset voltage. This tends to occur when the voltage on the input is equal or very close to the other input voltage. Adding hysteresis can prevent this problem. Hysteresis creates two switching thresholds (one for the rising input voltage and the other for the falling input voltage). Hysteresis is the voltage difference between the two switching thresholds. When both inputs are nearly equal, hysteresis causes one input to effectively move quickly pass the other. Thus, effectively moving the input out of region that oscillation may occur. For an inverting configured comparator, hysteresis can be added with a three resistor network and positive feedback. When input voltage (VIN) at the inverting node is less than non-inverting node (VT), the output is high. The equivalent circuit for the three resistor network is R1 in parallel with R3 and in series with R2. The lower threshold voltage VT1 is calculated by: VT1 = ((VS R2) / (((R1 R3) / (R1 + R3)) + R2)) (1) When VIN is greater than VT, the output voltage is low. The equivalent circuit for the three resistor network is R2 in parallel with R3 and in series with R1. The upper threshold voltage VT2 is calculated by: VT2 = VS ((R2 R3) / (R2 + R3)) / (R1 + ((R2 R3) / (R2 + R3))) (2) The hysteresis is defined as ΔVIN = VT1 – VT2 (3) Copyright © 2001–2013, Texas Instruments Incorporated Submit Documentation Feedback 5 Product Folder Links: LM397 |
Số phần tương tự - LM397 |
|
Mô tả tương tự - LM397 |
|
|
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 |