参数资料
| 型号： | ISL62881DHRTZ-T |
| 厂商： | Intersil |
| 文件页数： | 21/37页 |
| 文件大小： | 0K |
| 描述： | IC REG PWM SGL PHASE 32TQFN |
| 标准包装： | 6,000 |
| 应用： | 控制器，Intel IMVP-6.5? |
| 输入电压： | 4.5 V ~ 25 V |
| 输出数： | 1 |
| 输出电压： | 0.013 V ~ 1.5 V |
| 工作温度： | -10°C ~ 100°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 32-VFQFN 裸露焊盘 |
| 供应商设备封装： | 32-QFN（5x5） |
| 包装： | 带卷 (TR) |
| 配用： | ISL62881CCPUEVAL2Z-ND - EVAL BOARD ISL62881CCPU 28QFN |
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ISL62881C, ISL62881D
R i = ---------------------------------------
Transfer function A Rsen (s) always has unity gain at DC.
Current-sensing resistor R sen value will not have
significant variation over-temperature, so there is no
need for the NTC network.
The recommended values are R sum = 1k Ω and
C n = 5600pF.
Overcurrent Protection
Referring to Equation 1 and Figures 12, 13 and 19,
resistor R i sets the droop current I droop . Table 3 shows
the internal OCP threshold. It is recommended to design
I droop without using the R comp resistor.
For example, the OCP threshold is 60μA. We will design
I droop to be 50μA at full load, so the OCP trip level is 1.2x
of the full load current.
For inductor DCR sensing, Equation 16 gives the DC
relationship of V cn (s) and I o (s).
2R sen × I omax (EQ. 23)
I droopmax
where I omax is the full load current, I droopmax is the
corresponding droop current. For example, given
R sen = 1m Ω , I omax = 22A and I droopmax = 50μA,
Equation 23 gives R i = 880 Ω .
A resistor from COMP to GND can adjust the internal OCP
threshold, providing another dimension of fine-tune
flexibility. Table 3 shows the detail. It is recommended to
scale I droop such that the default OCP threshold gives
approximately the desired OCP level, then use R comp to
fine tune the OCP level if necessary.
Load Line Slope
Refer to Figure 12.
For inductor DCR sensing, substitution of Equation 17
into Equation 2 gives the load line slope expression in
V Cn = ? ------------------------------------------ × DCR ? × I o
V droop 2R droop R ntcnet
? R ntcnet ?
? R ntcnet + R sum ?
(EQ. 16)
Equation 24.
LL = ------------------- = ----------------------- × ------------------------------------------ × DCR
I o R i R ntcnet + R sum
(EQ. 24)
I droop = ----- × ------------------------------------------ × DCR × I o
Substitution of Equation 16 into Equation 1 gives:
2 R ntcnet (EQ. 17)
R i R ntcnet + R sum
For resistor sensing, substitution of Equation 21 into
Equation 2 gives the load line slope expression in
( R ntcnet + R sum ) × I droop
V droop 2R sen × R droop (EQ. 25)
Therefore:
2R ntcnet × DCR × I o
R i = ----------------------------------------------------------------------
(EQ. 18)
LL = ------------------- = -------------------------------------------
I o R i
Substitution of Equation 18 and rewriting Equation 24,
2 × ---------------------------------------------------- × DCR × I omax
( R ntcs + R ntc ) × R p
R i = ------------------------------------------------------------------------------------------------------------------
? ---------------------------------------------------- + R sum ? × I droopmax
R droop = ---------------- × LL
Substitution of Equation 8 and application of the OCP
condition in Equation 18 gives:
( R ntcs + R ntc ) × R p
R ntcs + R ntc + R p (EQ. 19)
? ?
? R ntcs + R ntc + R p ?
where I omax is the full load current, I droopmax is the
corresponding droop current. For example, given
R sum = 1.82k Ω , R p = 11k Ω , R ntcs = 2.61k Ω , R ntc = 10k Ω ,
DCR = 1.3m Ω , I omax = 22A and I droopmax = 50μA,
Equation 19 gives R i = 873 Ω .
or substitution of Equation 22 and rewriting Equation 25
I o (EQ. 26)
I droop
One can use the full load condition to calculate R droop .
For example, given I omax = 22A, I droopmax = 50μA and
LL = 7m Ω , Equation 26 gives R droop = 3.08k Ω .
It is recommended to start with the R droop value
calculated by Equation 26, and fine tune it on the actual
board to get accurate load line slope. One should record
the output voltage readings at no load and at full load for
load line slope calculation. Reading the output voltage at
I droop = ----- × R sen × I o
For resistor sensing, Equation 20 gives the DC
relationship of V cn (s) and I o (s).
V Cn = R sen × I o
Substitution of Equation 20 into Equation 1 gives
Equation 21:
2
R i
(EQ. 20)
(EQ. 21)
lighter load instead of full load will increase the
measurement error.
Current Monitor
Referring to Equation 6 for the IMON pin current
expression.
Refer to Figures 1 and 2, the IMON pin current flows
through R imon . The voltage across R imon is shown in
Equation 27:
R i = ----------------------------
I droop = ------------------- × LL
Therefore :
2R sen × I o (EQ. 22)
I droop
Substitution of Equation 22 and application of the OCP
condition in Equation 18 give s:
21
V Rimon = 3 × I droop × R imon
Rewriting Equation 26 gives Equation 28:
I o
R droop
(EQ. 27)
(EQ. 28)
FN7596.0
March 8, 2010
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| ISL62881HRTZ | 功能描述:直流/直流开关调节器 1 PHS PWM BUCKG FOR MICROPROCESR PWR SUP RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| ISL62881HRTZ-T | 功能描述:直流/直流开关调节器 1 PHS PWM BUCKG FOR MICROPROCESR PWR SUP RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| ISL62882 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Multiphase PWM Regulator for IMVP-6.5 Mobile CPUs and GPUs |
| ISL62882B | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Multiphase PWM Regulator for IMVP-6.5 Mobile CPUs and GPUs |
| ISL62882BHRTZ | 功能描述:直流/直流开关调节器 2 PHS PWM BUCKG FOR MICROPROC PWR SUP RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
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