参数资料
| 型号： | ISL6561CR-T |
| 厂商： | Intersil |
| 文件页数： | 23/26页 |
| 文件大小： | 0K |
| 描述： | IC CTRLR PWM MULTIPHASE 40-QFN |
| 标准包装： | 4,000 |
| 应用： | 控制器，Intel VR10X |
| 输入电压： | 3 V ~ 12 V |
| 输出数： | 4 |
| 输出电压： | 0.84 V ~ 1.6 V |
| 工作温度： | 0°C ~ 70°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 40-VFQFN 裸露焊盘 |
| 供应商设备封装： | 40-QFN（6x6） |
| 包装： | 带卷 (TR) |
ISL6561
voltage deviation is less than the allowable maximum.
Neglecting the contribution of inductor current and regulator
response, the output voltage initially deviates by an amount
Input Supply Voltage Selection
The VCC input of the ISL6561 can be connected either
directly to a +5V supply or through a current limiting resistor
? V ≈ ( ESL ) ----- + ( ESR ) ? I
di
dt
(EQ. 27)
to a +12V supply. An integrated 5.8V shunt regulator
maintains the voltage on the VCC pin when a +12V supply is
used. A 300 ? resistor is suggested for limiting the current
into the VCC pin to a worst-case maximum of approximately
The filter capacitor must have sufficiently low ESL and ESR
so that ? V < ? V MAX .
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 and
Equation 2), a voltage develops across the bulk-capacitor
ESR equal to I C,P P (ESR). Thus, once the output capacitors
are selected, the maximum allowable ripple voltage,
V PP(MAX) , determines the lower limit on the inductance.
25mA.
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 MOSFETs , 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 Output Filter Design . Choose the
lowest switching frequency that allows the regulator to meet
the transient-response requirements.
1000
IN – N V OUT V
? V ?
L ≥ ( ESR ) ------------------------------------------------------------
? ? OUT
f S V IN V PP ( MAX )
(EQ. 28)
100
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
? V MAX . This places an upper limit on inductance.
10
10
100 1000
SWITCHING FREQUENCY (kHz)
10000
Equation 29 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 30
addresses the leading edge. Normally, the trailing edge
dictates the selection of L because duty cycles are usually
FIGURE 15. R T vs SWITCHING FREQUENCY
Switching frequency is determined by the selection of the
frequency-setting resistor, R T (see the figures labeled
Typical Application on pages 3 and 6). Figure 15 and
Equation 31 are provided to assist in selecting the correct
L ≤ --------------------- ? V MAX – ? I ( ESR )
2NCV O
( ? I ) 2
(EQ. 29)
value for R T .
R T = 1.0203 ( 10 )
·
[ 10.6258- ( 1.03167 ) log ( f S ) ]
– 1200
(EQ. 31)
L ≤ -------------------------- ? V MAX – ? I ( ESR ) ? V IN – V O ?
( ? I ) 2
( 1.25 ) NC
? ?
(EQ. 30)
Input Capacitor Selection
The input capacitors are responsible for sourcing the ac
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.
23
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.
FN9098.5
May 12, 2005
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相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL6561CRZ | 功能描述:IC CTRLR PWM MULTIPHASE 40-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 |
| ISL6561CRZ | 制造商:Intersil Corporation 功能描述:Pulse Width Modulation (PWM) Controller |
| ISL6561CRZA | 功能描述:IC CTRLR PWM MULTIPHASE 40-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 |
| ISL6561CRZA-T | 功能描述:IC CTRLR PWM MULTIPHASE 40-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 |
| ISL6561CRZR5208 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Intersil Corporation 功能描述: |
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