参数资料
| 型号： | ISL6264CRZ |
| 厂商： | Intersil |
| 文件页数： | 21/23页 |
| 文件大小： | 0K |
| 描述： | IC CORE CTRLR TWO-PHASE 40-QFN |
| 标准包装： | 50 |
| 应用： | 控制器，AMD 移动式 Turion? |
| 输入电压： | 5 V ~ 24 V |
| 输出数： | 1 |
| 输出电压： | 0.38 V ~ 1.55 V |
| 工作温度： | -10°C ~ 100°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： | 管件 |
ISL6264
2.25
2.2
2.15
2.1
needs to be a high grade cap like X7R with low tolerance.
There is another consideration in order to achieve better
time constant match mentioned above. The NPO/COG
(class-I) capacitors have only 5% tolerance and a very good
thermal characteristics. But those caps are only available in
small capacitance values. In order to use such capacitors,
the resistors and thermistors surrounding the droop voltage
sensing and droop amplifier has to be resized up to 10X to
reduce the capacitance by 10X. But attention has to be paid
2.05
0
20
40
60
80
100
in balancing the impedance of droop amplifier in this case.
INDUCTOR TEMPERATURE (°C)
FIGURE 33. LOAD LINE PERFORMANCE WITH NTC
THERMAL COMPENSATION
Dynamic Mode of Operation - Dynamic Droop
Using DCR Sensing
Droop is very important for load transient performance. If the
system is not compensated correctly, the output voltage
could sag excessively upon load application and potentially
create a system failure. The output voltage could also take a
long period of time to settle to its final value. This could be
problematic if a load dump were to occur during this time.
This situation would cause the output voltage to rise above
the no load setpoint of the controller and could potentially
damage the CPU.
The L/DCR time constant of the inductor must be matched to
the Rn*C n time constant as shown in Equation 18:
Dynamic Mode of Operation - Compensation
Parameters
Considering the voltage regulator as a black box with a
voltage source controlled by VID and a series impedance, in
order to achieve the 2.0mV/A load line, the impedance
needs to be 2.0m Ω . The compensation design has to target
the output impedance of the controller to be 2.0m Ω . There is
a mathematical calculation file available to the user. The
power stage parameters such as L and C s are needed as the
input to calculate the compensation component values.
Attention has to be paid to the input resistor to the FB pin. It
is better to keep this resistor at 1k Ω for the convenience of
OFFSET design.
Static Mode of Operation - Current Balance Using
DCR or Discrete Resistor Current Sensing
Current Balance is achieved in the ISL6264 through the
------------- = ---------------------------------- ? C n
R n + RS EQV
L
C n = -----------------------------------
R n ? RS EQV
L R n ? RS EQV
DCR
Solving for C n , we now have Equation 19:
-------------
DCR
----------------------------------
R n + RS EQV
(EQ. 18)
(EQ. 19)
matching of the voltages present on the ISEN pins. The
ISL6264 adjusts the duty cycles of each phase to maintain
equal potentials on the ISEN pins. RL and CL around each
inductor, or around each discrete current resistor, are used
to create a rather large time constant such that the ISEN
voltages have minimal ripple voltage and represent the DC
current flowing through each channel's inductor. For
optimum performance, RL is chosen to be 10k Ω and CL is
selected to be 0.22μF. When discrete resistor sensing is
Note, R O was neglected. As long as the inductor time
constant matches the C n , R n and R S time constants as given
above, the transient performance will be optimum. As in the
Static Droop Case, this process may require a slight
adjustment to correct for layout inconsistencies. For the
example of L = 0.36 H with 0.8m Ω DCR, C n is calculated as
used, a capacitor most likely needs to be placed in parallel
with RL to properly compensate the current balance circuit.
ISL6264 uses RC filter to sense the average voltage on
phase node and forces the average voltage on the phase
node to be equal for current balance. Even though the
ISL6264 forces the ISEN voltages to be almost equal, the
0.36 μ H
C n = ------------------------------------------------------------------- = 330nF
shown in Equation 20:
--------------------
0.0008
parallel ( 5.823k, 1.825k )
(EQ. 20)
inductor currents will not be exactly equal. Take DCR current
sensing as example, two errors have to be added to find the
total current imbalance.
The value of this capacitor is selected to be 330nF. As the
inductors tend to have 20% to 30% tolerances, this cap
generally will be tuned on the board by examining the
transient voltage. If the output voltage transient has an initial
dip (lower than the voltage required by the load line) and
slowly increases back to the steady state, the cap is too
small and vice versa. It is better to have the cap value a little
bigger to cover the tolerance of the inductor to prevent the
output voltage from going lower than the spec. This cap
21
1. Mismatch of DCR: If the DCR has a 5% tolerance then
the resistors could mismatch by 10% worst case. If each
phase is carrying 20A then the phase currents mismatch
by 20A*10% = 2A.
2. Mismatch of phase voltages/offset voltage of ISEN pins.
The phase voltages are within 2mV of each other by
current balance circuit. The error current that results is
given by 2mV/DCR. If DCR = 1m Ω then the error is 2A.
FN6359.3
May 28, 2009
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| ISL6264CRZ-T | 功能描述:IC CORE CTRLR TWO-PHASE 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 |
| ISL6265 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Multi-Output Controller with Integrated MOSFET Drivers for AMD SVI Capable |
| ISL6265A | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Multi-Output Controller with Integrated MOSFET Drivers for AMD SVI Capable Mobile CPUs |
| ISL6265AHRTZ | 功能描述:电流型 PWM 控制器 MULTI-OUTPUT CNTRLRS PHS W/EMBEDDED GATE 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 |
| ISL6265AHRTZ-T | 功能描述:电流型 PWM 控制器 MULTI-OUTPUT CNTRLRS PHS W/EMBEDDED GATE 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 |
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