参数资料
| 型号： | ISL6333IRZ |
| 厂商： | Intersil |
| 文件页数： | 31/40页 |
| 文件大小： | 0K |
| 描述： | IC CTRLR PWM 3PHASE BUCK 48-QFN |
| 标准包装： | 43 |
| 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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ISL6333, ISL6333A, ISL6333B, ISL6333C
board, whether through-hole components are permitted, the
total board space available for power-supply circuitry, and
the maximum amount of load current. Generally speaking,
OUTPUT CURRENT, 50A/DIV
0A
OUTPUT VOLTAGE,
500mV/DIV
0V
FIGURE 19. OVERCURRENT BEHAVIOR IN HICCUP MODE
Individual Channel Overcurrent Limiting
The controllers have the ability to limit the current in each
individual channel without shutting down the entire regulator.
This is accomplished by continuously comparing the sensed
currents of each channel with a constant 140μA OCL
reference current, as shown in Figure 18. If a channel’s
individual sensed current exceeds this OCL limit, the UGATE
signal of that channel is immediately forced low, and the
LGATE signal is forced high. This turns off the upper
the most economical solutions are those in which each
phase handles between 25A and 30A. All surface-mount
designs will tend toward the lower end of this current range.
If through-hole MOSFETs and inductors can be used, higher
per-phase currents are possible. In cases where board
space is the limiting constraint, current can be pushed as
high as 40A per phase, but these designs require heat sinks
and forced air to cool the MOSFETs, inductors and
heat-dissipating surfaces.
MOSFETS
The choice of MOSFETs depends on the current each
MOSFET will be required to conduct, the switching frequency,
the capability of the MOSFETs to dissipate heat, and the
availability and nature of heat sinking and air flow.
LOWER MOSFET POWER CALCULATION
The calculation for power loss in the lower MOSFET is
simple, since virtually all of the loss in the lower MOSFET is
due to current conducted through the channel resistance
(r DS(ON) ). In Equation 24, I M is the maximum continuous
output current, I P-P is the peak-to-peak inductor current (see
Equation 1), and d is the duty cycle (V OUT /V IN ).
? I M ? 2 I L ( P-P ) 2 ( 1 – d )
P LOW ( 1 ) = r DS ( ON ) ? ? ------ ? ? ( 1 – d ) + ----------------------------------------
MOSFET(s), turns on the lower MOSFET(s), and stops the
rise of current in that channel, forcing the current in the
channel to decrease. That channel’s UGATE signal will not
? N ? 12
(EQ. 24)
be able to return high until the sensed channel current falls
back below the 140μA reference.
During VID-on-the-fly transitions the OCL trip level is
boosted to prevent false overcurrent limiting events that can
occur. Starting from the beginning of a dynamic VID
transition, the overcurrent trip level is boosted to 196μA. The
OCL level will stay at this boosted level until 50μs after the
end of the dynamic VID transition, at which point it will return
An additional term can be added to the lower-MOSFET loss
equation to account for additional loss accrued during the dead
time when inductor current is flowing through the
lower-MOSFET body diode. This term is dependent on the
diode forward voltage at I M , V D(ON) , the switching frequency,
f S , and the length of dead times, t d1 and t d2 , at the beginning
and the end of the lower-MOSFET conduction interval
respectively.
? IM
P LOW ( 2 ) = V D ( ON ) ? f S ? ? ------ + I ----------- ? ? t
? I
+ ? ------ – ----------- ? ? t d2
2 ? ?
? N
to the typical 140μA trip level.
MOSFETs General Design Guide
? N 2 ?
?
P-P
d1
?
?
M I P-P
(EQ. 25)
This design guide is intended to provide a high-level
explanation of the steps necessary to create a multi-phase
power converter. It is assumed that the reader is familiar with
many of the basic skills and techniques referenced in the
following. In addition to this guide, Intersil provides complete
reference designs that include schematics, bills of materials,
and example board layouts for all common microprocessor
applications.
Power Stages
The first step in designing a multi-phase converter is to
determine the number of phases. This determination
depends heavily on the cost analysis, which in turn depends
on system constraints that differ from one design to the next.
Principally, the designer will be concerned with whether
components can be mounted on both sides of the circuit
31
The total maximum power dissipated in each lower MOSFET
is approximated by the summation of P LOW(1) and P LOW(2) .
UPPER MOSFET POWER CALCULATION
In addition to r DS(ON) losses, a large portion of the
upper-MOSFET losses are due to currents conducted across
the input voltage (V IN ) during switching. Since a substantially
higher portion of the upper-MOSFET losses are dependent on
switching frequency, the power calculation is more complex.
Upper MOSFET losses can be divided into separate
components involving the upper-MOSFET switching times,
the lower-MOSFET body-diode reverse-recovery charge, Q rr ,
and the upper MOSFET r DS(ON) conduction loss.
FN6520.3
October 8, 2010
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相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL6333IRZ-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 |
| ISL6334ACRZ | 功能描述:IC CTRLR PWM 4PHASE BUCK 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 |
| ISL6334ACRZR5368 | 功能描述:IC CTRLR PWM 4PHASE BUCK 40QFN 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 |
| ISL6334ACRZ-T | 功能描述:IC CTRLR PWM 4PHASE BUCK 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 |
| ISL6334ACRZ-TR5368 | 功能描述:IC CTRLR PWM 4PHASE BUCK 40QFN 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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