參數(shù)資料
型號: AT1314S-GRE
廠商: Aimtron Technology Corp.
英文描述: High-Efficiency Step-Down Current Regulator For LEDs
中文描述: 高效率降壓型LED的電流調節(jié)器
文件頁數(shù): 10/12頁
文件大小: 320K
代理商: AT1314S-GRE
AT1314
Preliminary Product Information
High-Efficiency Step-Down
Current Regulator For LEDs
For low ESR ceramic capacitors, the output ripple is dominated by the charging or
discharging of the output capacitor.
In the case of low-ESR electrolytic capacitors, Output ripple voltage drop caused by
the switching current through the ESR of the output capacitor. The output ripple is
estimated as:
R
I
V
×
Impacting frequency stability of the overall control loop, the output capacitance, in
conjunction with the inductor, creates a double pole inside the feedback loop. In
addition the capacitance and the ESR value create a zero. These frequency response
effects together with the internal frequency compensation circuitry of AT1314 modify
the gain and phase shift of the closed loop system.
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW:
http://www.aimtron.com.tw
3/24/2006 REV:2.0 Email:
service@aimtron.com.tw
ESR
L
RIPPLE
Compensation
The step-down loop can be compensated by adjusting the external components
connected to the COMP pin. The COMP pin is connected to the output of the internal
trans-conductance error amplifier. The compensation capacitor adjusts the low
frequency gain , and the series resistor value adjusts the high frequency gain. A series
capacitor-resistor combination sets a pole-zero combination to control the
characteristics of the control system. The system has 2 poles and one zero of
importance, 2 poles consist of compensation capacitor and output capacitor. One zero
is produced by the compensation capacitor and the compensation resistor.
If electrolytic capacitor with relatively high ESR is used, the zero due to the
capacitance and ESR of the output capacitor can be compensated by a third pole set
by the compensation resistor and another compensation capacitor connected form
COMP pin to ground.
PCB layout guidelines
Careful printed circuit layout is extremely important to avoid causing parasitical
capacitance and line inductance. The following layout guidelines are recommended to
achieve optimum performance.
Please the buck converter diode and inductor close to the SW pin and no via.
Please ceramic bypass capacitors near the input pin.
Locate all feedback resistive dividers as close to their respective feedback pins as
possible.
Use wide traces and trace length is short as possible.
相關PDF資料
PDF描述
AT1361 1MHz,1A Synchronous Buck Converter
AT1361X_GRE 1MHz,1A Synchronous Buck Converter
AT1362 Synchronous Buck Converter With Power Good Detector & LDO
AT1362A Synchronous Buck Converter With Power Good Detector & LDO
AT1362AN Synchronous Buck Converter With Power Good Detector & LDO
相關代理商/技術參數(shù)
參數(shù)描述
AT13169 制造商:Delphi Corporation 功能描述:SPRING HOLDER
AT-1319-10-8-ST-ADAPT- 制造商:TE Connectivity 功能描述:AT-1319-10-8-ST-ADAPT-AS
AT-1319-10-8-ST-ADAPT-AS 制造商:TE Connectivity 功能描述:AD-1319-10
AT-1319-11-12-ST-ADP-A 制造商:TE Connectivity 功能描述:AT-1319-11-12-ST-ADP-ASY
AT-1319-11-12-ST-ADP-ASY 功能描述:手工工具 AT-1319-11 RoHS:否 制造商:Molex 產品:Extraction Tools 類型: 描述/功能:Extraction tool