参数资料
型号: IRDC3831
厂商: International Rectifier
文件页数: 21/31页
文件大小: 0K
描述: BOARD EVAL SYNC BUCK CONVERTER
产品变化通告: (EP) Parts Discontinuation 25/May/2012
标准包装: 1
系列: SupIRBuck™
主要目的: DC/DC,步降
输出及类型: 1,非隔离
输出电压: 0.75V
电流 - 输出: 8A
输入电压: 12V
稳压器拓扑结构: 降压
频率 - 开关: 400kHz
板类型: 完全填充
已供物品:
已用 IC / 零件: IR3831
IR3831MPbF
Detailed calculation of compensation TypeIII
Desired Phase Margin Θ = 70 o
Programming the Current-Limit
The Current-Limit threshold can be set by
connecting a resistor (R OCSET ) from the SW pin
to the OCSet pin. The resistor can be calculated
F Z 2 = F o
F P 2 = F o
1 ? sin Θ
1 + sin Θ
1 + sin Θ
1 ? sin Θ
= 10.58 kHz
= 340.28 kHz
by using equation (4). This resistor R OCSET must
be placed close to the IC.
The R DS(on) has a positive temperature
coefficient and it should be considered for the
worst case operation.
Select : F Z 1 = 0 . 5 * F Z 2 = 5.29 kHz and
I SET = I L ( critical ) =
R OCSet ? I OCSet
R DS ( on )
.......... .......... ... (32)
F P 3 = 0.5 * F s = 200 kHz
Select : C 7 = 2.2 nF
Calculate R 3 , C 3 and C 4 :
R DS ( on ) = 8.7 m Ω * 1.5 = 13.05 m Ω
I SET ? I o ( LIM ) = 8 A * 1.5 = 12 A
(50% over nominal output current)
I OCSet = 39.22 μ A (at F s = 400 kHz)
R OCSet = 3.99 k Ω Select R 7 = 4.02 k Ω
R 3 =
2 π * F o * L o * C o * V osc
C 7 * V in
; R 3 = 1.48 k Ω
Setting the Power Good Threshold
Power Good threshold is internally set at 0.515 V.
When the voltage at the FB pin exceeds the
Select : R 3 = 1.47 k Ω
threshold, PGood is asserted.
The PGood is an open drain output. Hence, it is
C 4 =
1
2 π * F Z 1 * R 3
; C 4 = 20.47 nF, Select : C 4 = 22 nF
necessary to use a pull up resistor R PG from
PGood pin to Vcc. The value of the pull-up
resistor must be chosen such as to limit the
current flowing into the PGood pin, when the
C 3 =
1
2 π * F P 3 * R 3
; C 3 = 541.34 pF , Select : C 3 = 560 pF
output voltage is not in regulation, to less than 5
mA. A typical value used is 4.7k ? .
Calculate R 10 , R 8 and R 9 :
R 10 =
R 8 =
1
2 π * C 7 * F P 2
1
2 π * C 7 * F Z 2
; R 10 = 215 Ω , Select : R 10 = 210 Ω
- R 10 ; R 8 = 6.63 k Ω ,
Select : R 8 = 6.65 k Ω
11/05/10
21
相关PDF资料
PDF描述
EBM08DRAS CONN EDGECARD 16POS R/A .156 SLD
GBC25DCMH-S288 CONN EDGECARD 50POS .100 EXTEND
EBM18DCWS CONN EDGECARD 36POS DIP .156 SLD
EBM12DCCN CONN EDGECARD 24POS R/A .156 SLD
EBM12DCCH CONN EDGECARD 24POS R/A .156 SLD
相关代理商/技术参数
参数描述
IRDC3831W 功能描述:电源管理IC开发工具 User Guide IR3831W Eval Brd RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
IRDC3832W 功能描述:电源管理IC开发工具 User Guide IR3832W Eval Brd RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
IRDC3837 功能描述:电源管理IC开发工具 User Guide IR3837 Eval Brd RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
IRDC3837 制造商:International Rectifier 功能描述:; MCU Supported Families:IR3837; Feature
IRDC3838 功能描述:电源管理IC开发工具 User Guide IR3838 Eval Brd RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V