参数资料
| 型号： | ISL6308AIRZ-T |
| 厂商： | Intersil |
| 文件页数： | 21/28页 |
| 文件大小： | 0K |
| 描述： | IC CTRLR PWM BUCK 3PHASE 40-QFN |
| 标准包装： | 4,000 |
| 应用： | 控制器，DDR |
| 输入电压： | 5 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： | 40-VFQFN 裸露焊盘 |
| 供应商设备封装： | 40-QFN（6x6） |
| 包装： | 带卷 (TR) |
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ISL6308A
initial load transient spike, as shown in Figure 18. Follow the
steps below to ensure the R-C and inductor L/DCR time
constants are matched accurately.
C 2 (OPTIONAL)
1. Capture a transient event with the oscilloscope set to
about L/DCR/2 (sec/div). For example, with L = 1μH and
R 2
C 1
COMP
DCR = 1m Ω , set the oscilloscope to 500μs/div.
2. Record Δ V1 and Δ V2 as shown in Figure 18.
3. Select a new value, R COMP,2 , for the time constant
resistor based on the original value, R COMP,1 , using
Equation 27.
R 1
FB
ISL6308A
R COMP , 2 = R COMP , 1 ? ----------
Δ V
Δ V 1
2
(EQ. 27)
VDIFF
4. Replace R COMP with the new value and check to see that
the error is corrected. Repeat the procedure if necessary.
After choosing a new value for R COMP , it will most likely be
necessary to adjust the value of R S to obtain the desired full
load droop voltage. Use Equation 26 to obtain the new value
for R S .
Compensation
The two opposing goals of compensating the voltage
regulator are stability and speed. Depending on whether the
regulator employs the optional load-line regulation, as
there are two distinct methods for achieving these goals.
Compensating the Load-Line Regulated Converter
The load-line regulated converter behaves in a similar
manner to a peak current mode controller because the two
poles at the output filter L-C resonant frequency split with the
introduction of current information into the control loop. The
final location of these poles is determined by the system
function, the gain of the current signal, and the value of the
compensation components, R 2 and C 1 .
FIGURE 19. COMPENSATION CONFIGURATION FOR
LOAD-LINE REGULATED ISL6308A CIRCUIT
Since the system poles and zero are affected by the values
of the components that are meant to compensate them, the
solution to the system equation becomes fairly complicated.
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.
The feedback resistor, R 1 , has already been chosen as
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 double pole frequency and the ESR zero
frequency. For each of the following three, there is a
separate set of equations for the compensation components.
--------------------------- > F 0
Case 1:
1
2 π ? L ? C
R 2 = R 1 ? ------------------------------------------------------------
0.66 ? V
2 π ? V OSC ? R 1 ? f 0
Δ V 1
Δ V 2
V OUT
2 π ? F 0 ? V OSC ? L ? C
IN
0.66 ? V IN
C 1 = -------------------------------------------------
--------------------------- ≤ F 0 < ---------------------------------
I TRAN
Case 2:
1 1
2 π ? L ? C 2 π ? C ? ESR
V OSC ? ( 2 π ) 2 ? F 0 ? L ? C
Δ I
2
0.66 ? V
R 2 = R 1 ? ----------------------------------------------------------------
IN
(EQ. 28)
C 1 = --------------------------------------------------------------------------------
( 2 π ) ? F 0 ? V OSC ? R 1 ? L ? C
FIGURE 18. TIME CONSTANT MISMATCH BEHAVIOR
21
2
0.66 ? V IN
FN6669.0
September 9, 2008
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| ISL6308CRZ | 功能描述:电压模式 PWM 控制器 DAC-LESS MULTI-PHS PWM CNTRLR W/3-DRVRS RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
| ISL6308CRZR5374 | 制造商:Intersil Corporation 功能描述:ISL6308CRZ W/ 24HR BURN-IN - Rail/Tube 制造商:Intersil Corporation 功能描述:IC CTRLR PWM 3PHASE BUCK 40-QFN 制造商:Intersil 功能描述:ISL6308CRZ W/24HRU RN-IN |
| ISL6308CRZ-T | 功能描述:电压模式 PWM 控制器 DAC-LESS MULTI-PHS PWM CNTRLR W/3-DRVRS RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
| ISL6308CRZ-TR5374 | 制造商:Intersil Corporation 功能描述:ISL6308CRZ W/ 24HR BURN-IN - Tape and Reel 制造商:Intersil Corporation 功能描述:IC CTRLR PWM 3PHASE BUCK 40-QFN 制造商:Intersil 功能描述:ISL6308CRZ W/24HRU RN-IN |
| ISL6308CRZ-TR5453 | 制造商:Intersil Corporation 功能描述:STD. ISL6308CRZ-T W/GOLD BOND WIRE ONLY - Tape and Reel |
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