收藏本站
AOZ1977
Application Information
DutyCycle = D = ----------------------------
Iripple = ---------------------------------
ONtime = dt = -----------
D = ---------------------------------- = 0.28
dt = --------------------- = 2.8 us
0.3 ? Vin ? ? Vout – Vin ?
Fsw ? L ? Vout
dt ? Vin 2.8 us ? 130 V
L = --------------------- = ------------------------------------ = 656 uH
Inductor Selection
Inductor choice will be affected by many parameters,
including duty cycle based on input/output setting,
switching frequency, full scale LED current level, and
mode of operations. The boost controller can operate
under discontinuous mode, continuous mode, or critical
conduction mode. For high voltage boost LED driver
applications, it is recommended to use critical conduction
mode for good stability and best efficiency.
ILpeak
Inductor Current in Critical Conduction Mode
In critical conduction mode:
ILpeak = di = 2 ? Iin
The duty cycle for the boost DC/DC system is defined as:
Vout – Vin
V OUT
To determine the ON time for the boost switch:
D
Fsw
For the application with VIN = 130 V, VOUT = 180 V,
LED current = 200mA:
- 180 V ? 0.2 A
lin = -------------------------------- = 0.277 A
130 V
di = 2 ? 0.277 A = 0.555 A
180 V – 130 V
180 V
0.28
100 kHz
The inductor value is determined by:
di 0.555 A
After the inductor value is calculated, we need to
consider the DCR resistance and the Isat saturation
current of the inductor. Inductor DCR is inversely
proportional to the Isat. It is recommended to select an
inductor for which the Isat value should be at least 50 %
higher than the ILpeak value. To minimize the EMI effect,
it is always preferable to use shielded type inductors.
Diode Selection
It is recommended to use fast recovery diode for D1.
For most applications, Schottky diodes with correct
current and voltage ratings are suitable. The diode
current rating should be at least higher than the full scale
LED current. The diode voltage rating should be higher
than the OVP level of VOUT voltage.
Output Capacitors
The amount and type of capacitor used is mainly
determined by the design output ripple requirement, and
mainly by the output ripple current which is usually higher
for boost converters and equals:
Vout – Vin
Vin
When selecting output capacitors, it is more important to
check the effective ESR of the capacitor than the actual
capacitance value. For example, a 10 ? F capacitor with
0.02 ? ESR will handle higher ripple current but produce
less output ripple than a 33 ? F capacitor with 0.04 ?
ESR. It is recommended to use low ESR MLCC ceramic
capacitors. For high voltage cost effective application,
multiple Electrolytic capacitors in parallel will reduce the
total effective ESR.
Input Capacitors
The input capacitors for boost converters do not require
low ESR due to the fact that the input current is
continuous. Also, they do not contain large peak current
as compared to the output capacitors.
The ripple current at the input capacitor is:
Iin_ripple = ---------------------------------------------------------------
where Fsw is the switching frequency, 100 kHz in this
example.
Electrolytic capacitors should work well with the
appropriate voltage and ripple current rating, it is not
recommended to use Tantalum capacitors because
Boost converters do exhibit high surge currents during
startup which can cause tantalum capacitors to fail.
Rev. 2.1 May 2012
www.aosmd.com
Page 11 of 16
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
AP-104-NT 12V PLUG TRANSFORMER EMPTY CASE
AP-120 PLUG AUTO LOCKING BLACK
AP-121 PLUG AUTO LOCKING BLACK W/LED
AP-124 12V AUTO PLUG STD EURO CE
AP-129 PLUG 12V AUTO EURO CE
AP-130 PLUG 12V AUTO LED SW FUSE CE
AP-131 PLUG 12V AUTO MINI FUSE CE
AP-132 12V AUTO PLUG ADPT-AIRCRAFT PLUG
相关代理商/技术参数
AOZ1978 制造商:AOSMD 制造商全称:Alpha & Omega Semiconductors 功能描述:Dual Channel High Voltage LED Driver IC
AOZ1995MI 制造商:Alpha & Omega Semiconductor 功能描述:IC DISPLAY DRIVER
AOZ2002PI 功能描述:Linear Voltage Regulator IC Positive Adjustable 1 Output Adj to 0.8V 2A 8-SO Exposed Pad 制造商:alpha & omega semiconductor inc. 系列:- 包装:带卷（TR） 零件状态:有效 稳压器拓扑:正，可调式 电压 - 输出:可调至 0.8V 电流 - 输出:2A 电压 - 跌落（典型值）:0.18V @ 2A 稳压器数:1 电压 - 输入:1.3 V ~ 5.5 V 电流 - 限制（最小值）:2.2A 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 供应商器件封装:8-SO 裸露焊盘 标准包装:3,000
AOZ2003 制造商:AOSMD 制造商全称:Alpha & Omega Semiconductors 功能描述:3A Ultra Low Dropout Linear Regulator
AOZ2003PI 制造商:Alpha & Omega Semiconductor 功能描述:IC REG LDO ADJ 3A 8SO
AOZ2013PI 制造商:Alpha & Omega Semiconductor 功能描述:IC REGULATOR
AOZ2023PI 功能描述:Linear Voltage Regulator IC Positive Adjustable 1 Output 0.8 V ~ 6 V 3A 8-SO Exposed Pad 制造商:alpha & omega semiconductor inc. 系列:- 包装:带卷（TR） 零件状态:有效 稳压器拓扑:正，可调式 电压 - 输出:0.8 V ~ 6 V 电流 - 输出:3A 电压 - 跌落（典型值）:0.18V @ 2A 稳压器数:1 电压 - 输入:1.3 V ~ 5.5 V 电流 - 限制（最小值）:- 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-SOIC（0.154"，3.90mm 宽）裸焊盘 供应商器件封装:8-SO 裸露焊盘 标准包装:3,000
AOZ2151EQI-30