参数资料
| 型号： | ISL8101IRZ-T |
| 厂商： | Intersil |
| 文件页数： | 8/20页 |
| 文件大小： | 0K |
| 描述： | IC PWM CTRLR BUCK 2PHASE 24-QFN |
| 标准包装： | 6,000 |
| 应用： | 控制器，Intel VRM9，VRM10，AMD Hammer 应用 |
| 输入电压： | 4.6 V ~ 12 V |
| 输出数： | 1 |
| 输出电压： | 0.6 V ~ 2.3 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 24-VFQFN 裸露焊盘 |
| 供应商设备封装： | 24-QFN（4x4） |
| 包装： | 带卷 (TR) |
ISL8101
INTERLEAVING
The switching of each channel in a ISL8101-based converter
is timed to be symmetrically out of phase with the other
channel. As a result, the two-phase converter has a
combined ripple frequency twice the frequency of one of its
phases. In addition, the peak-to-peak amplitude of the
combined inductor currents is proportionately reduced.
ripple is a function of capacitance, capacitor equivalent
series resistance (ESR), and inductor ripple current.
Reducing the inductor ripple current allows the designer to
use fewer or less costly output capacitors (should output
ripple be an important design parameter).
C IN CURRENT
Increased ripple frequency and lower ripple amplitude
generally translate to lower per-channel inductance and
lower total output capacitance for a given set of performance
specifications.
Q1 D-S CURRENT
I L1 + I L2
I L2
PWM2
I L1
PWM1
FIGURE 2. PWM AND INDUCTOR-CURRENT WAVEFORMS
FOR 2-PHASE CONVERTER
Figure 2 illustrates the additive effect on output ripple
frequency. The two channel currents (I L1 and I L2 ), combine
to form the AC ripple current and the DC load current. The
ripple component has two times the ripple frequency of each
individual channel current.
To understand the reduction of ripple current amplitude in the
multiphase circuit, examine Equation 4 representing an
individual channel’s peak-to-peak inductor current.
Q3 D-S CURRENT
FIGURE 3. INPUT CAPACITOR CURRENT AND INDIVIDUAL
CHANNEL CURRENTS IN A 2-PHASE
CONVERTER
Another benefit of interleaving is the reduction of input ripple
current. Input capacitance is determined in a large part by
the maximum input ripple current. Multiphase topologies can
improve overall system cost and size by lowering input ripple
current and allowing the designer to reduce the cost of input
capacitance. The example in Figure 3 illustrates input
currents from a two-phase converter combining to reduce
the total input ripple current.
input-capacitor RMS current based on load current and duty
cycle. The figure is provided as an aid in determining the
optimal input capacitor solution.
( V IN – V OUT ) ? V OUT
L ? f S ? V
I L , P-P = ----------------------------------------------------------
IN
(EQ. 4)
PWM OPERATION
One switching cycle for the ISL8101 is defined as the time
between consecutive PWM pulse terminations (turn-off of
V IN and V OUT are the input and output voltages,
respectively, L is the single-channel inductor value, and f S is
the switching frequency.
The output capacitors conduct the ripple component of the
inductor current. In the case of multiphase converters, the
capacitor current is the sum of the ripple currents from each
of the individual channels (see Equation 5).
the upper MOSFET on a channel). Each cycle begins when
a switching clock signal commands the upper MOSFET to
go off. The other channel’s upper MOSFET conduction is
terminated 1/2 of a cycle later.
Once a channel’s upper MOSFET is turned off, the lower
MOSFET remains on for a minimum of 1/3 cycle. This forced
off time is required to assure an accurate current sample.
L ? f S ? V
( V IN – N ? V OUT ) ? V OUT
I P-P = --------------------------------------------------------------------
IN
(EQ. 5)
Following the 1/3-cycle forced off time, the controller enables
the upper MOSFET output. Once enabled, the upper
MOSFET output transitions high when the sawtooth signal
Peak-to-peak ripple current, I P-P , decreases by an amount
proportional to the number of channels. Output-voltage
8
crosses the adjusted error-amplifier output signal, as
illustrated in the ISL8101’s block diagram. Just prior to the
upper drive turning the MOSFET on, the lower MOSFET
FN9223.1
July 28, 2008
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相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL8102 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Two-Phase Buck PWM Controller with High Current Integrated MOSFET Drivers |
| ISL8102CRZ | 功能描述:IC REG CTRLR BUCK PWM VM 32-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:100% 电源电压:8.2 V ~ 30 V 降压:无 升压:无 回扫:是 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:0°C ~ 70°C 封装/外壳:8-DIP（0.300"，7.62mm） 包装:管件 产品目录页面:1316 (CN2011-ZH PDF) |
| ISL8102CRZ-T | 功能描述:IC REG CTRLR BUCK PWM VM 32-QFN RoHS:是 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) |
| ISL8102EVAL1 | 功能描述:EVAL BOARD 1 FOR ISL8102 RoHS:否 类别:编程器，开发系统 >> 评估板 - DC/DC 与 AC/DC（离线）SMPS 系列:* 标准包装:1 系列:- 主要目的:DC/DC，步降 输出及类型:1，非隔离 功率 - 输出:- 输出电压:3.3V 电流 - 输出:3A 输入电压:4.5 V ~ 28 V 稳压器拓扑结构:降压 频率 - 开关:250kHz 板类型:完全填充 已供物品:板 已用 IC / 零件:L7981 其它名称:497-12113STEVAL-ISA094V1-ND |
| ISL8102IRZ | 功能描述:IC REG CTRLR BUCK PWM VM 32-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:100% 电源电压:8.2 V ~ 30 V 降压:无 升压:无 回扫:是 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:0°C ~ 70°C 封装/外壳:8-DIP（0.300"，7.62mm） 包装:管件 产品目录页面:1316 (CN2011-ZH PDF) |
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