参数资料
| 型号： | ISL6265CHRTZ |
| 厂商： | Intersil |
| 文件页数： | 19/27页 |
| 文件大小： | 0K |
| 描述： | IC CTRLR MULTI-OUTPUT 48TQFN |
| 标准包装： | 50 |
| 应用： | 控制器，AMD SVI 兼容移动式 CPU |
| 输入电压： | 5 V ~ 24 V |
| 输出数： | 3 |
| 输出电压： | 0.5 V ~ 1.55 V |
| 工作温度： | -10°C ~ 100°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 48-WFQFN 裸露焊盘 |
| 供应商设备封装： | 48-TQFN-EP（6x6） |
| 包装： | 管件 |
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ISL6265C
Current Sense
Core and Northbridge regulators feature two different types of
current sense circuits.
selected, such that the R-C time constant matches the inductor
L/DCR time constant (see Equation 9), then V C is equal to the
voltage drop across the DCR multiplied by the ratio of the resistor
divider, K.
------------- = -------------------- 2 - ? C 1
R 1 + R 2
CORE CONTINUOUS CURRENT SENSE
The ISL6265C provides for load current to be measured using
DCR
L R 1 ? R
(EQ. 9)
either resistors in series with the individual output inductors or
using the intrinsic series resistance of the inductors as shown in
the applications circuits in Figures 3 and 4. The load current in a
particular output is sampled continuously every switching cycle.
During this time, the current-sense amplifier uses the current
sense inputs to reproduce a signal proportional to the inductor
current. This sensed current is a scaled version of the inductor
current.
The inductor current sense information is used for current
balance in dual plane applications, overcurrent detection in core
outputs and output voltage droop depending on controller
configuration.
CORE DCR TEMPERATURE COMPENSATION
It may also be necessary to compensate for changes in inductor
DCR due to temperature. DCR shifts due to temperature cause
time constant mismatch, skewing inductor current accuracy.
MOSFET
UGATE
V IN
L
I
L
DCR
V OUT
Potential problems include output voltage droop and OC trip
point, both shifting significantly from expected levels. The
addition of a negative temperature coefficient (NTC) resistor to
the R-C network compensates for the rise in DCR due to
DRIVER LGATE
ISL6265C INTERNAL CIRCUIT
INDUCTOR
V L (s)
V C (s)
R 1 C 1
R 2
C OUT
temperature. Typical NTC values are in the 10k ? range. A second
resistor, R 3 , in series with the NTC allows for more accurate time-
constant and resistor-ratio matching as the pair of resistors are
placed in parallel with R 2 (Figure 10). The NTC resistor must be
placed next to the inductor for good heat transfer, while R 1 , R 2 ,
R 3 , and C 1 are placed close to the controller for interference
immunity.
CURRENT
SENSE
ISP
ISN
R NTC
R 3
OPTIONAL
NTC
NETWORK
CORE DCR COMPONENT SELECTION FOR DROOP
By adjusting the ratio between inductor DCR drop and the voltage
measured across the sense capacitor, the load line can be set to
any level, giving the converter the correct amount of droop at all
load currents.
Equation 10 shows the relation between droop voltage,
V DROOP = -------------- ? 5 ? V C , OC
I MAX
FIGURE 10. DCR SENSING COMPONENTS
Inductor windings have a characteristic distributed resistance or
DCR (Direct Current Resistance). For simplicity, the inductor DCR
is considered as a separate lumped quantity, as shown in
Figure 10. The inductor current, I L , flowing through the inductor,
passes through the DCR. Equation 6 shows the s-domain
equivalent voltage, V L , across the inductor.
maximum output current (I MAX ), OC trip level and current sense
capacitor voltage at the OC current level, V C(OC) .
(EQ. 10)
I OC
AMD specifications do not require droop and provide no load line
guidelines. Tight static output voltage tolerance limits push
acceptable level of droop below a useful level for Griffin
V L ( s ) = I L ? ( s ? L + DCR )
(EQ. 6)
applications. Care must be taken in applications which
implement droop to balance time constant mismatch, sense
? ------------- + 1 ?
? DCR
?
( R 1 ? R 2 )
V C ( s ) = ----------------------------------------------------------- ? K ? DCR ? I L
? s ? ------------------------ ? C 1 + 1 ?
R 2
(EQ. 8)
A simple R-C network across the inductor (R 1 , R 2 and C) extracts
the DCR voltage, as shown in Equation 7. The voltage across the
sense capacitor, V C , can be shown to be proportional to the
output current I L , shown in Equation 7.
s ? L
(EQ. 7)
? ?
? R 1 + R 2 ?
Where:
K = ---------------------
R 2 + R 1
Sensing the time varying inductor current accurately requires
that the parallel R-C network time constant match the inductor
L/DCR time constant. If the R-C network components are
19
capacitor resistor ratio, OC trip and droop equations.
Temperature shifts related to DCR must also be addressed, as
outlined in the previous section.
NORTHBRIDGE CURRENT SENSE
During the off-time following a PHASE transition low, the
Northbridge controller samples the voltage across the lower
MOSFET r DS(ON) . A ground-referenced amplifier is connected to
the PHASE node through a resistor, R OCSET_NB . The voltage across
R OCSET_NB is equal to the voltage drop across the r DS(ON) of the
lower MOSFET while it is conducting. The resulting current into
the OCSET_NB pin is proportional to the inductor current. The
sensed inductor current is used for overcurrent protection and
The Northbridge controller does not support output voltage
droop.
FN6976.2
January 11, 2013
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相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL6265CHRTZ-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 |
| ISL6265CIRTZ | 制造商:Intersil Corporation 功能描述:MULTI-OUTPUT CONTROLLER (SINGLE PHASE) WITH EMBEDDED GATE DR - Rail/Tube |
| ISL6265EVAL1Z | 制造商:Intersil Corporation 功能描述: |
| ISL6265HRTZ | 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 |
| ISL6265HRTZ-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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