参数资料
型号: ISL6324IRZ
厂商: Intersil
文件页数: 32/38页
文件大小: 0K
描述: IC HYBRID CTRLR PWM DUAL 48-QFN
标准包装: 43
应用: 控制器,AMD SVI
输入电压: 5 V ~ 12 V
输出数: 2
输出电压: 最高 2V
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
ISL6324
.
-------------------------------- > f 0
C 2 (OPTIONAL)
Case 1:
1
2 ? π ? L ? C
R C = R FB ? ----------------------------------------------------------
0.66 ? V
2 ? π ? V P-P ? R FB ? f 0
R C
C C
COMP
FB
2 ? π ? f 0 ? V P-P ? L ? C
IN
0.66 ? V IN
C C = ------------------------------------------------------
ISL6324
-------------------------------- ≤ f 0 < -------------------------------------
R FB
Case 2:
1 1
2 ? π ? L ? C 2 ? π ? C ? ESR
V P-P ? ( 2 ? π ) 2 ? f 02 ? L ? C
R C = R FB ? ------------------------------------------------------------------
( 2 ? π ) 2 ? f 02 ? V P-P ? R FB ? L ? C
VSEN
FIGURE 23. COMPENSATION CONFIGURATION FOR
LOAD-LINE REGULATED ISL6324 CIRCUIT
Since the system poles and zero are affected by the values
0.66 ? V IN
0.66 ? V IN
C C = ---------------------------------------------------------------------------------------
(EQ. 49)
f 0 > -------------------------------------
of the components that are meant to compensate them, the
solution to the system equation becomes fairly complicated.
Case 3:
1
2 ? π ? C ? ESR
R C = R FB ? ----------------------------------------------
2 ? π ? V P-P ? R FB ? f 0 ? L
Fortunately, there is a simple approximation that comes very
close to an optimal solution. Treating the system as though it
were a voltage-mode regulator, by compensating the L-C
poles and the ESR zero of the voltage mode approximation,
yields a solution that is always stable with very close to ideal
transient performance.
Select a target bandwidth for the compensated system, f 0 .
The target bandwidth must be large enough to assure
adequate transient performance, but smaller than 1/3 of the
per-channel switching frequency. The values of the
compensation components depend on the relationships of f 0
to the L-C pole frequency and the ESR zero frequency. For
each of the following three, there is a separate set of
2 ? π ? f 0 ? V P-P ? L
0.66 ? V IN ? ESR
0.66 ? V IN ? ESR ? C
C C = ------------------------------------------------------------------
Compensation Without Loadline Regulation
The non load-line regulated converter is accurately modeled
as a voltage-mode regulator with two poles at the L-C
resonant frequency and a zero at the ESR frequency. A
type-III controller, as shown in Figure 24, provides the
necessary compensation.
C 2
equations for the compensation components.
In Equation 49, L is the per-channel filter inductance divided
R C
C C
COMP
by the number of active channels; C is the sum total of all
output capacitors; ESR is the equivalent series resistance of
FB
the bulk output filter capacitance; and V P-P is the
peak-to-peak sawtooth signal amplitude as described in the
“Electrical Specifications” table on page 6.
Once selected, the compensation values in Equation 49
C 1
R 1
R FB
VSEN
ISL6324
assure a stable converter with reasonable transient
performance. In most cases, transient performance can be
improved by making adjustments to R C . Slowly increase the
value of R C while observing the transient performance on an
oscilloscope until no further improvement is noted. Normally,
C C will not need adjustment. Keep the value of C C from
Equation 49 unless some performance issue is noted.
The optional capacitor C 2 , is sometimes needed to bypass
noise away from the PWM comparator (see Figure 23). Keep
a position available for C 2 , and be prepared to install a high
frequency capacitor of between 22pF and 150pF in case any
leading edge jitter problem is noted.
32
FIGURE 24. COMPENSATION CIRCUIT WITHOUT LOAD-LINE
REGULATION
The first step is to choose the desired bandwidth, f 0 , of the
compensated system. Choose a frequency high enough to
assure adequate transient performance but not higher than 1/3
of the switching frequency. The type-III compensator has an
extra high-frequency pole, f HF . This pole can be used for added
noise rejection or to assure adequate attenuation at the error
amplifier high-order pole and zero frequencies. A good general
rule is to choose f HF = 10f 0 , but it can be higher if desired.
Choosing f HF to be lower than 10f 0 can cause problems with
too much phase shift below the system bandwidth as shown in
Equation 50.
FN6518.2
September 25, 2008
相关PDF资料
PDF描述
ISL6326BIRZ IC REG CTRLR BUCK PWM VM 40-QFN
ISL6326IRZ IC REG CTRLR BUCK PWM VM 40-QFN
ISL6327AIRZ IC REG CTRLR BUCK PWM 48-QFN
ISL6327IRZ IC REG CTRLR BUCK PWM 48-QFN
ISL6328AIRZ IC VOLTAGE REGULATOR
相关代理商/技术参数
参数描述
ISL6324IRZ-T 功能描述:IC HYBRID CTRLR PWM DUAL 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
ISL6326AIRZ 制造商:Rochester Electronics LLC 功能描述: 制造商:Intersil Corporation 功能描述:
ISL6326BCRZ 功能描述:电流型 PWM 控制器 W/ANNEAL 4-PHS VR11 CNTRLR COM 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
ISL6326BCRZ-T 功能描述:电流型 PWM 控制器 W/ANNEAL 4-PHS VR11 CNTRLR COM 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
ISL6326BIRZ 功能描述:电流型 PWM 控制器 W/ANNEAL 4-PHS VR11 CNTRLR IND 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