参数资料
型号: ISL6564AIRZ
厂商: Intersil
文件页数: 21/28页
文件大小: 0K
描述: IC REG CTRLR BUCK PWM VM 40-QFN
标准包装: 500
PWM 型: 电压模式
输出数: 1
频率 - 最大: 1.5MHz
占空比: 66.7%
电源电压: 4.75 V ~ 5.25 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 85°C
封装/外壳: 40-VFQFN 裸露焊盘
包装: 管件
ISL6564A
on pages 4 to 7, load current information can be obtained by
measuring the voltage between IOUT to ground when a NTC
network from IOUT pin to the ground is placed. The output
current at IOUT pin is proportional to load current as shown
in Figure 17.
V_IOUT, 200mV/DIV
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 heat dissipated in the lower MOSFET is
simple, since virtually all of the heat loss in the lower
MOSFET is due to current conducted through the channel
resistance (r DS(ON) ). In Equation 14, I M is the maximum
continuous output current; I PP is the peak-to-peak inductor
current (see Equation 1); d is the duty cycle (V OUT /V IN ); and
0A
50A
100A
L is the per-channel inductance.
? I M ? 2 I L , PP ( 1 – d )
P LOW , 1 = r DS ( ON ) ? ------ ? ( 1 – d ) + --------------------------------
FIGURE 17. VOLTAGE AT IOUT PIN WITH A NTC NETWORK
PLACED BETWEEN IOUT TO GROUND WHEN
? N ? 12
(EQ. 14)
LOAD CURRENT CHANGES
An additional term can be added to the lower-MOSFET loss
When selecting the equivalent resistor network components
values, it is important to ensure the voltage at IOUT pin not
exceed 2V.
When ISL6564A is operated at single phase mode (both
PWM3 and PWM4 connected to VCC and PWM2
unconnected). The output current at IOUT and IDROOP is
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.
P LOW , 2 = V D ( ON ) f S ? ------ + I --------- ? t
I PP ?
d1 + ? ------ – --------- ? t d2
half of the sensed phase current.
General Design Guide
I M PP
? N 2 ?
? I
M
? N 2 ?
(EQ. 15)
This design guide is intended to provide a high-level
explanation of the steps necessary to create a multiphase
power converter. It is assumed that the reader is familiar with
many of the basic skills and techniques referenced below. 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 multiphase 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
board; whether through-hole components are permitted; and
the total board space available for power-supply circuitry.
Generally speaking, the most economical solutions are
those in which each phase handles between 15 and 20A. All
surface-mount designs will tend toward the lower end of this
21
Thus 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.
When the upper MOSFET turns off, the lower MOSFET does
not conduct any portion of the inductor current until the
voltage at the phase node falls below ground. Once the
lower MOSFET begins conducting, the current in the upper
MOSFET falls to zero as the current in the lower MOSFET
FN6285.1
March 20, 2007
相关PDF资料
PDF描述
ISL6564IR-T IC REG CTRLR BUCK PWM VM 40-QFN
ISL6565BCV-T IC REG CTRLR BUCK PWM VM 28TSSOP
ISL6566AIRZ IC CTRLR PWM 3PHASE BUCK 40-QFN
ISL6566CRZ-T IC CTLR PWM BUCK 3PHASE 40-QFN
ISL6567CRZ IC REG CTRLR BUCK PWM VM 24-QFN
相关代理商/技术参数
参数描述
ISL6564AIRZ-T 功能描述:IC REG CTRLR BUCK PWM VM 40-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:275kHz 占空比:50% 电源电压:18 V ~ 110 V 降压:无 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:-40°C ~ 85°C 封装/外壳:8-SOIC(0.154",3.90mm 宽) 包装:带卷 (TR)
ISL6564CR 功能描述:IC REG CTRLR BUCK PWM VM 40-QFN RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:4,000 系列:- PWM 型:电压模式 输出数:1 频率 - 最大:1.5MHz 占空比:66.7% 电源电压:4.75 V ~ 5.25 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 85°C 封装/外壳:40-VFQFN 裸露焊盘 包装:带卷 (TR)
ISL6564CR-T 功能描述:IC REG CTRLR BUCK PWM VM 40-QFN RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:4,000 系列:- PWM 型:电压模式 输出数:1 频率 - 最大:1.5MHz 占空比:66.7% 电源电压:4.75 V ~ 5.25 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 85°C 封装/外壳:40-VFQFN 裸露焊盘 包装:带卷 (TR)
ISL6564CRZ 功能描述:电流型 PWM 控制器 LEAD-FREE MULTI-PHASE PWM CONTROLLER W/ 0.525-1.3 VID RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14
ISL6564CRZ-T 功能描述:电流型 PWM 控制器 LEAD-FREE MULTI-PHASE PWM CONTROLLER W/ 0.525-1.3 VID, T&R RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14