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参数资料
| 型号： | ISL62882EVAL2Z |
| 厂商： | Intersil |
| 文件页数： | 23/42页 |
| 文件大小： | 0K |
| 描述： | EVALUATION BOARD FOR ISL62882 |
| 标准包装： | 1 |
| 系列： | Robust Ripple Regulator™ (R³) |
| 主要目的： | DC/DC，步降 |
| 输出及类型： | 1，非隔离 |
| 输出电压： | 0.3 ~ 1.5V |
| 电流 - 输出： | 60A |
| 输入电压： | 4.5 ~ 20 V |
| 稳压器拓扑结构： | 降压 |
| 频率 - 开关： | 300kHz |
| 板类型： | 完全填充 |
| 已供物品： | 板 |
| 已用 IC / 零件： | ISL62882 |
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ISL62882, ISL62882B
V Cn = ? ----------------------------------------- × ------------ ? × I o
R sum
N
? ?
R ip and C ip form an R-C branch in parallel with R i , providing a
lower impedance path than R i at the beginning of i o change. R ip
and C ip do not have any effect at steady state. Through proper
selection of R ip and C ip values, i droop can resemble i o rather than
i L , and V o will not ring back. The recommended value for R ip is
100 Ω . C ip should be determined through tuning the load
transient response waveforms on an actual board. The
recommended range for C ip is 100pF~2000pF. However, it
should be noted that the R ip -C ip branch may distort the i droop
waveform. Instead of being triangular as the real inductor
current, i droop may have sharp spikes, which may adversely
affect i droop average value detection and therefore may affect
OCP accuracy. User discretion is advised.
Resistor Current-Sensing Network
Overcurrent Protection
Refer to Equation 1 on page 16 and Figures 12, 17 and 23;
resistor R i sets the droop current I droop . Table 4 shows the
internal OCP threshold. It is recommended to design I droop
without using the R comp resistor.
For example, the OCP threshold is 40μA for 2-phase solution. We
will design I droop to be 34.3μA at full load, so the OCP trip level is
1.16x of the full load current.
For inductor DCR sensing, Equation 23 gives the DC relationship
of V cn (s) and I o (s).
? ?
? R ntcnet DCR ?
(EQ. 23)
N
? R ntcnet + -------------- ?
PHASE1
PHASE2
Substitution of Equation 23 into Equation 1 gives Equation 24:
I droop = ----- × ----------------------------------------- × ------------ × I o
R i R sum
L
DCR
L
DCR
Therefore:
2 R ntcnet DCR
N
R ntcnet + --------------
N
(EQ. 24)
R sum
RSUM
RSUM
ISUM+
2R ntcnet × DCR × I o
R i = --------------------------------------------------------------------------------
? ? N
N × ? R ntcnet + -------------- ? × I droop
(EQ. 25)
RSEN
RSEN
RO
VCN
CN
RI
ISUM-
Substitution of Equation 15 and application of the OCP condition
in Equation 25 gives Equation 26:
2 × --------------------------------------------------- × DCR × I omax
( R ntcs + R ntc ) × R p
R sum ?
R i = -------------------------------------------------------------------------------------------------------------------------
N × ? --------------------------------------------------- + -------------- ? × I droopmax
IO
RO
( R ntcs + R ntc ) × R p
R ntcs + R ntc + R p
?
? R ntcs + R ntc + R p N ?
(EQ. 26)
V Cn ( s ) = ------------ × I o ( s ) × A Rsen ( s )
R sen
N
V Cn = ------------ × I o
R sen
FIGURE 23. RESISTOR CURRENT-SENSING NETWORK
Figure 23 shows the resistor current-sensing network for a
2-phase solution. Each inductor has a series current-sensing
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 20 thru 22 give
V Cn (s) expression
(EQ. 20)
where I omax is the full load current, I droopmax is the
corresponding droop current. For example, given N = 2,
R sum = 3.65k Ω , R p = 11k Ω , R ntcs = 2.61k Ω , R ntc = 10k Ω ,
DCR = 0.88m Ω , I omax = 51A and I droopmax = 34.3μA,
Equation 26 gives R i = 998 Ω .
For resistor sensing, Equation 27 gives the DC relationship of
V cn (s) and I o (s).
(EQ. 27)
N
Substitution of Equation 27 into Equation 1 gives Equation 28:
A Rsen ( s ) = ----------------------
1 + ------------
I droop = ----- × ------------ × I o
R i
1
s
ω sns
(EQ. 21)
Therefore
2 R sen
N
(EQ. 28)
ω Rsen = ---------------------------
-------------- × C n
2R sen × I o
R i = ---------------------------
1
R sum
N
(EQ. 22)
(EQ. 29)
N × I droop
Substitution of Equation 29 and application of the OCP condition
N × I droopmax
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.
23
in Equation 25 gives Equation 30:
2R sen × I omax
R i = --------------------------------------
(EQ. 30)
FN6890.4
June 21, 2011
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| ISL62882HRTZ | 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 |
| ISL62882HRTZ-T | 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 |
| ISL62882IRTZ | 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 |
| ISL62882IRTZ-T | 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 |
| ISL62883 | 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 |
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