参数资料
| 型号： | ISL6353CRTZ |
| 厂商： | Intersil |
| 文件页数： | 20/30页 |
| 文件大小： | 0K |
| 描述： | IC CONTROLLER DDR VR12 40TQFN |
| 标准包装： | 60 |
| 应用： | 控制器，DDR，Intel VR12 |
| 输入电压： | 4.5 V ~ 25 V |
| 输出数： | 1 |
| 输出电压： | 0.25 V ~ 1.52 V |
| 工作温度： | 0°C ~ 70°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 40-WFQFN 裸露焊盘 |
| 供应商设备封装： | 40-TQFN-EP（5x5） |
| 包装： | 管件 |
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ISL6353
IMON voltage should be approximately a square wave with little
or no overshoot. In regulators without droop control the capacitor
value can be selected to err on the high side to overdamp the
current sense input to the controller to avoid overshoots.
Resistor Current-Sensing Network
Phase1 Phase2 Phase3
and 20μA in PS2 mode. For a 2-phase design, the OCP threshold
is 60μA in PS0 mode and 30μA in PS1 and PS2 mode. The
ISL6353 declares a OCP fault when I sense is above the threshold
for 120μs.
Referring to Equation 3 and Figure 10, resistor R i sets the sensed
current I sense . In general, I sense can be set to 40μA at the
maximum load current expected in the design. The OCP trip level
will be 1.5 times the maximum load current with a threshold at
L
L
L
60μA. The OCP ratio can be set to something other than 1.5
DCR
DCR
DCR
Rsum
times the maximum load current by setting
I sense = 60μA/OCP ratio .
For inductor DCR sensing, Equation 13 gives the DC relationship
V Cn = ? ----------------------------------------- × ------------ ? × I o
R sum
? ?
Rsen
Rsen
Rsen
Rsum
Rsum
Ro
Vcn
Cn
Ri
ISUM+
ISUM-
of V cn (s) and I o (s).
? ?
? R ntcnet DCR ?
N
N
? R ntcnet + -------------- ?
(EQ. 13)
Ro
Substitution of Equation 13 into Equation 3 gives Equation 14:
II sense = ----- × ----------------------------------------- × ------------ × I o
R sum
R i
R i = --------------------------------------------------------------------------------
N × ? R ntcnet + -------------- ? × I sense
Ro
Io
FIGURE 11. RESISTOR CURRENT-SENSING NETWORK
Figure 11 shows the precision resistor current-sensing network
for a 3-phase solution. Each inductor has a series current-sensing
Therefore :
? N ?
1 R ntcnet DCR
N
R ntcnet + --------------
R ntcnet × DCR × I o
R sum
N
(EQ. 14)
(EQ. 15)
V Cn ( s ) = ------------ × I o ( s ) × A Rsen ( s )
--------------------------------------------------- × DCR × I omax
R i =
(EQ. 16)
N × ? --------------------------------------------------- + -------------- ? × I sensemax
R ntcs + R ntc + R p
? ?
resistor, R sen . R sum and R o are connected to the R sen pads to
accurately capture the inductor current information. The R sum
and R o resistors are connected to capacitor C n . R sum and C n
form a filter for noise attenuation. Equations 10 through 12 give
V Cn (s) expressions:
R sen (EQ. 10)
N
Substitution of Equation 5 and application of the full load
condition in Equation 15 gives Equation 16:
( R ntcs + R ntc ) × R p
R ntcs + R ntc + R p
--------------------------------------------------------------------------------------------------------------------------
? ( R ntcs + R ntc ) × R p R sum ?
N
A Rsen ( s ) = ----------------------
1 + ------------
1
s
ω sns
(EQ. 11)
where I omax is the full load current, and I sensemax is the
corresponding sensed current based on the desired OCP to I omax
ratio.
ω Rsen = ---------------------------
1
R sum
V Cn = ------------ × I o
I sense = ----- × ------------ × I o
R i
(EQ. 12)
N
-------------- × C n
Transfer function A Rsen (s) always has unity gain at DC. The
current-sensing resistor R sen value will not have a significant
variation over temperature, so there is no need for the NTC
network.
Recommended values are R sum = 1k Ω and C n = 5600pF.
For resistor sensing, Equation 17 gives the DC relationship of
V cn (s) and I o (s).
R sen (EQ. 17)
N
Substitution of Equation 17 into Equation 3 gives Equation 18:
1 R sen (EQ. 18)
N
Therefore:
N × I sense
N × I sensemax
Overcurrent Protection
The ISL6353 implements overcurrent protection (OCP) by
comparing the average value of the measured current I sense with
an internal current source reference. The OCP threshold is 60μA
for 3-phase, 2-phase and 1-phase PS0 operation. In PS1/2 mode
the OCP threshold is scaled based on the number of active
phases in PS1/2 mode divided by the number of active phases in
PS0 mode. For example, if the regulator operates in 3-phase
mode in PS0, 2-phase in PS1 mode and 1-phase in PS2 mode,
the OCP threshold will be 60μA in PS0 mode, 40μA in PS1 mode
R sen × I o
R i = --------------------------
Application of the full load condition gives Equation 20:
R sen × I omax
R i = -------------------------------------
where I omax is the full load current, and I sensemax is the
corresponding sensed current.
(EQ. 19)
(EQ. 20)
20
September 15, 2011
FN6897.0
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相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL6353CRTZ-T | 功能描述:电流型 PWM 控制器 VR12 MEMORY CNTRLR 3 PHS 2 INT 5V DRVRS 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 |
| ISL6353CRTZ-TS2568 | 制造商:Intersil Corporation 功能描述:INTEL, ISL6353CRTZ-T W/BARCODE LABELS, 12 MONTH D/C RESTRICT - Tape and Reel |
| ISL6353CRZ | 制造商:Intersil 功能描述:Multiphase PWM Regulator for VR12 DDR Memory Systems |
| ISL6353IRTZ | 功能描述:电流型 PWM 控制器 VR12 MEMORY CNTRLR 3 PHS 2 INT 5V DRVRS 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 |
| ISL6353IRTZ-T | 功能描述:电流型 PWM 控制器 VR12 MEMORY CNTRLR 3 PHS 2 INT 5V DRVRS 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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