数据搜索系统,热门电子元器件搜索 |
|
LB1696 数据表(PDF) 7 Page - Sanyo Semicon Device |
|
LB1696 数据表(HTML) 7 Page - Sanyo Semicon Device |
7 / 9 page 7. Current limiter The current limiter turns off the sink side output transistor when the output current-set current value (limiter value) is reached. The output current is limited by the limit value. The RF pin is used to detect the output current. The output current is detected as voltage by connecting resistor Rf between RF pin and GND. When the RF pin voltage reaches 0.5 V (typ), the current limiter operates so that the output current is limited to the 0.5/Rf-set limiter value. 7-1. Output off time The current limiter is so designed that current limit function turns on to turn off the sink side output transistor and then turn on the transistor again after off period of a fixed time (output off time) has elapsed. Since the LB1696 uses this output switching method for the current limiter, the ASO problems when current limitation goes into operated mode as compared with the output unsaturated current limited one. In addition, by separating current limiter operation into two modes, one when the motor is locked and one when the motor is rotating (during start-up), it was possible to implement a current limiter circuit with excellent motor start-up characteristics. The explanation of current limiter operation below is divided into two parts: one for the mode used when the motor is locked and one for the mode used when the motor is rotating. The output off time depends on the charge time of capacitor C connected to the C pin. When the current limiter turns on, C begins charging and the output is kept off until C is charged up to 2 V (typ). When C has been charged up to 2 V, the sink side output turns on again. The C charging current is a constant-regulated current, which depends on resistor R1 connected to the R1 pin and resistor R2 connected to the R2 pin. In the LB1696, the charge current can be switched for when the motor is locked and for when the motor is rotating in order to support motors for a large number of applications. As a result, it is possible to set the output off time so that it is different for when the motor is locked and for when the motor is rotating. By setting the output off time so that it is shorter when the motor is rotating (at start-up) as opposed to when the motor is locked, it is possible to reduce the decrease in torque at start-up caused by the output off time. The charge currents and output off times for when the motor is locked and for when the motor is rotating are as follows: (1) Charge current ICL1 and output off time toff1 when the motor is locked ICL1 6 1.4/R1 toff1 6 C/ICL1 × 2.0 6 1.42 × R1 × C (R1 must be set between 14 k Ω and 100 kΩ.) (2) Charge current ICL2 and output off time toff2 when the motor is rotating ICL2 6 ICL1 + (1.4/R2) toff2 6 C/ICL2 × 2.0 6 1.42 × R × C{R=R1 × R2/(R1 + R2)} (R2 must be set between 7 k Ω and 100 kΩ.) LB1696 No.5244-7/9 |
类似零件编号 - LB1696 |
|
类似说明 - LB1696 |
|
|
链接网址 |
隐私政策 |
ALLDATASHEETCN.COM |
ALLDATASHEET是否为您带来帮助? [ DONATE ] |
关于 Alldatasheet | 广告服务 | 联系我们 | 隐私政策 | 链接交换 | 制造商名单 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 |