参数资料
| 型号： | ISL6322CRZ |
| 厂商： | Intersil |
| 文件页数： | 37/41页 |
| 文件大小： | 0K |
| 描述： | IC CTRLR PWM 4PHASE BUCK 48-QFN |
| 标准包装： | 43 |
| 应用： | 控制器，Intel VR10、VR11、AMD CPU |
| 输入电压： | 5 V ~ 12 V |
| 输出数： | 1 |
| 输出电压： | 0.38 V ~ 1.99 V |
| 工作温度： | 0°C ~ 70°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 |
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ISL6322
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
capacitor ESR equal to I C(P-) (ESR). Thus, once the output
capacitors are selected, the maximum allowable ripple
voltage, V (P-P)(MAX) , determines the lower limit on the
inductance.
1000
100
– N ? V OUT ? ? V OUT
? V
L ≥ ESR ? --------------------------------------------------------------------
? IN ?
f S ? V IN ? V ( P – P ) ( MAX )
(EQ. 44)
Since the capacitors are supplying a decreasing portion of
the load current while the regulator recovers from the
10
10k
100k 1000k
SWITCHING FREQUENCY (Hz)
10000k
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 45 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 46
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
FIGURE 25. R T vs SWITCHING FREQUENCY
Input Capacitor Selection
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(P-P) = 0 I L(P-P) = 0.5 I O
L ≤ --------------------------------- ? Δ V MAX – ( Δ I ? ESR )
----------------------------- ? Δ V MAX – ( Δ I ? ESR ) ? ? V IN – V O ?
L ≤ 1.25
( Δ I ) 2
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.
2 ? N ? C ? V O
(EQ. 45)
( Δ I ) 2
? N ? C
(EQ. 46)
? ?
Switching Frequency
0.2
0.1
I L(P-P) = 0.25 I O
I L(P-P) = 0.75 I O
There are a number of variables to consider when choosing
0
0
0.2
0.4
0.6
0.8
1.0
the switching frequency, as there are considerable effects on
the upper MOSFET loss calculation. These effects are
outlined in “MOSFETs” on page 31, and they establish the
upper limit for the switching frequency. The lower limit is
established by the requirement for fast transient response
and small output-voltage ripple as outlined in “Compensation
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 47
are provided to assist in selecting the correct value for R T .
DUTY CYCLE (V O/ V IN )
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(P-P) ) to I O . Select a
bulk capacitor with a ripple current rating that 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.
R T = 10
[ 10.61 – ( 1.035 ? log ( f S ) ) ]
(EQ. 47)
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.
37
FN6328.2
August 2, 2007
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| ISL6322CRZ-T | 功能描述:IC CTRLR PWM 4PHASE BUCK 48-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,000 系列:- 应用:电源，ICERA E400，E450 输入电压:4.1 V ~ 5.5 V 输出数:10 输出电压:可编程 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:42-WFBGA，WLCSP 供应商设备封装:42-WLP 包装:带卷 (TR) |
| ISL6322GCRZ | 功能描述:IC CTRLR PWM 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) |
| ISL6322GCRZ-T | 功能描述:IC CTRLR PWM 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 |
| ISL6322GIRZ | 功能描述:IC CTRLR PWM 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) |
| ISL6322GIRZ-T | 功能描述:IC CTRLR PWM 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 |
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