参数资料
| 型号： | ISL6329IRZ-T |
| 厂商： | Intersil |
| 文件页数： | 33/38页 |
| 文件大小： | 0K |
| 描述： | IC CTRLR PWM SYNC BUCK DL 60QFN |
| 标准包装： | 4,000 |
| 应用： | 控制器，AMD SVI |
| 输入电压： | 5 V ~ 12 V |
| 输出数： | 2 |
| 输出电压： | 0.0125 V ~ 1.55 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | * |
| 封装/外壳： | * |
| 供应商设备封装： | * |
| 包装： | * |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页当前第33页第34页第35页第36页第37页第38页
ISL6329
Most capacitor solutions rely on a mixture of high frequency
capacitors with relatively low capacitance in combination with
bulk capacitors having high capacitance but limited
high-frequency performance. Minimizing the ESL of the
high-frequency capacitors allows them to support the output
voltage as the current increases. Minimizing the ESR of the bulk
capacitors allows them to supply the increased current with less
output voltage deviation.
The ESR of the bulk capacitors also creates the majority of the
output-voltage ripple. As the bulk capacitors sink and source the
inductor AC ripple current (see “Interleaving” on page 12 and
Equation 3), a voltage develops across the bulk capacitor ESR
1k
100
equal to I C,PP (ESR). Thus, once the output capacitors are
selected, the maximum allowable ripple voltage, V PP(MAX) ,
determines the lower limit on the inductance.
10
10k
100k 1M
SWITCHING FREQUENCY (Hz)
10M
IN – N ? V OUT ? V OUT
? V ?
L ≥ ESR ? --------------------------------------------------------------------
? ?
f S ? V IN ? V PP ( MAX )
(EQ. 40)
FIGURE 25. R T vs SWITCHING FREQUENCY
Input Capacitor Selection
Since the capacitors are supplying a decreasing portion of the
load current while the regulator recovers from the transient, the
capacitor voltage becomes slightly depleted. The output
inductors must be capable of assuming the entire load current
before the output voltage decreases more than Δ V MAX . This
places an upper limit on inductance.
Equation 41 gives the upper limit on L for the cases when the
trailing edge of the current transient causes a greater
output-voltage deviation than the leading edge. Equation 42
addresses the leading edge. Normally, the trailing edge dictates
the selection of L because duty cycles are usually less than 50%.
Nevertheless, both inequalities should be evaluated, and L
should be selected based on the lower of the two results. In each
equation, L is the per-channel inductance, C is the total output
capacitance, and N is the number of active channels.
The input capacitors are responsible for sourcing the AC
component of the input current flowing into the upper MOSFETs.
Their RMS current capacity must be sufficient to handle the AC
component of the current drawn by the upper MOSFETs which is
related to duty cycle and the number of active phases.
0.3
I L,PP = 0 I L,PP = 0.5 I O
I L,PP = 0.25 I O I L,PP = 0.75 I O
0.2
0.1
L ≤ --------------------------------- ? Δ V MAX – ( Δ I ? ESR )
2 ? N ? C ? V O
( Δ I ) 2
(EQ. 41)
L ≤ ----------------------------- ? Δ V MAX – ( Δ I ? ESR ) ? ? V IN – V O ?
( Δ I ) 2
1.25 ? N ? C
? ?
(EQ. 42)
0
0
0.2
0.4
0.6
0.8
1.0
DUTY CYCLE (V O/ V IN )
Switching Frequency
There are a number of variables to consider when choosing the
switching frequency, as there are considerable effects on the
upper MOSFET loss calculation. These effects are outlined in
switching frequency. The lower limit is established by the
requirement for fast transient response and small output-voltage
ripple as outlined in “Output Filter Design” on page 32. Choose
the lowest switching frequency that allows the regulator to meet
the transient-response requirements.
Switching frequency is determined by the selection of the
frequency-setting resistor, R T . Figure 25 and Equation 43 are
provided to assist in selecting the correct value for R T .
FIGURE 26. NORMALIZED INPUT-CAPACITOR RMS CURRENT vs DUTY
CYCLE FOR 4-PHASE CONVERTER
For a four-phase design, use Figure 26 to determine the input-
capacitor RMS current requirement set by the duty cycle, maximum
sustained output current (I O ), and the ratio of the peak-to-peak
inductor current (I L,PP ) to I O . Select a bulk capacitor with a ripple
current rating which will minimize the total number of input
capacitors required to support the RMS current calculated.
The voltage rating of the capacitors should also be at least 1.25
times greater than the maximum input voltage. Figures 27 and 28
provide the same input RMS current information for three-phase
and two-phase designs respectively. Use the same approach for
selecting the bulk capacitor type and number.
R T = 10
[ 10.61 – ( 1.035 ? log ( f S ) ) ]
33
(EQ. 43)
FN7800.0
April 19, 2011
相关PDF资料 |
PDF描述 |
|---|---|
| ISL6333IRZ | IC CTRLR PWM 3PHASE BUCK 48-QFN |
| ISL6334AIRZR5368 | IC CTRLR PWM 4PHASE BUCK 40QFN |
| ISL6334BIRZ-T | IC CTRLR PWM SYNC BUCK 40-QFN |
| ISL6334CRZ | IC CTRLR PWM 4PHASE BUCK 40-QFN |
| ISL6334DIRZ | IC CTRLR PWM 4PHASE VR11.1 40QFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL6333ACRZ | 功能描述:IC CTRLR PWM 3PHASE BUCK 48-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
| ISL6333ACRZ-T | 功能描述:IC CTRLR PWM 3PHASE BUCK 48-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
| ISL6333AEVAL1Z | 制造商:Intersil Corporation 功能描述: |
| ISL6333AIRZ | 功能描述:IC CTRLR PWM 3PHASE BUCK 48-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:2,000 系列:- 应用:控制器，DSP 输入电压:4.5 V ~ 25 V 输出数:2 输出电压:最低可调至 1.2V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:30-TFSOP（0.173"，4.40mm 宽） 供应商设备封装:30-TSSOP 包装:带卷 (TR) |
| ISL6333AIRZ-T | 功能描述:IC CTRLR PWM 3PHASE BUCK 48-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
发布紧急采购，3分钟左右您将得到回复。