参数资料
| 型号： | ISL6328IRZ |
| 厂商： | Intersil |
| 文件页数： | 14/33页 |
| 文件大小： | 0K |
| 描述： | IC CTRLR PWM SYNC BUCK DL 48QFN |
| 标准包装： | 50 |
| 应用： | 控制器，AMD SVI |
| 输入电压： | 5 V ~ 12 V |
| 输出数： | 2 |
| 输出电压： | 0.0125 V ~ 1.55 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | * |
| 封装/外壳： | * |
| 供应商设备封装： | * |
| 包装： | * |
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ISL6328
Continuous Current Sampling
In order to realize proper current-balance, the currents in each
channel are sampled continuously every switching cycle. During
this time, the current-sense amplifier uses the ISEN inputs to
MOSFET
UGATE(n)
V IN
L
I
L
n
DCR
V OUT
reproduce a signal proportional to the inductor current, I L . This
sensed current, I SEN , is simply a scaled version of the inductor
current.
DRIVER
LGATE(n)
INDUCTOR
V L (s)
V C (s)
C OUT
ISL6328 INTERNAL
R 1
C
R 2
PWM
CIRCUIT
ISENn-
SWITCHING PERIOD
I L
I n
+
-
ISENn+
C ISEN
V C (s)
R ISEN
I SEN
FIGURE 4. INDUCTOR DCR CURRENT SENSING
CONFIGURATION
I SEN
multiplied by the ratio of the resistor divider, K. If a resistor
divider is not being used, the value for K is 1.
L R 1 ? R 2
R 1 + R 2
TIME
------------ = -------------------- ? C
DCR
(EQ. 8)
(EQ. 9)
I SEN = I L ? ---------------
R
FIGURE 3. CONTINUOUS CURRENT SAMPLING
The ISL6328 supports Inductor DCR current sensing to continuously
sample each channel’s current for channel-current balance. The
internal circuitry shown in Figure 4 represents Channel n of an
n-Channel converter. This circuitry is repeated for each channel in
the converter, but may not be active depending on how many
channels are operating.
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 4. The channel current I Ln , flowing through the inductor,
passes through the DCR. Equation 5 shows the S-domain
equivalent voltage, V L , across the inductor.
The capacitor voltage V C , is then replicated across the effective
internal sense resistor, R ISEN . This develops a current through
R ISEN which is proportional to the inductor current. This current,
I SEN , is continuously sensed and is then used by the controller for
load-line regulation, channel-current balancing, and overcurrent
detection and limiting. Equation 9 shows that the proportion
between the channel current, I L , and the sensed current, I SEN , is
driven by the value of the effective sense resistance, R ISEN , and
the DCR of the inductor.
DCR
ISEN
The Northbridge regulator samples the load current in the same
manner as the Core regulator does.
V L ( s ) = I L ? ( s ? L + DCR )
n
(EQ. 5)
The sampled currents, I n , from each active channel are summed
together and divided by the number of active channels. this
? ------------ + 1 ?
s ? L
? DCR
?
( R 1 ? R 2 )
V C ( s ) = ------------------------------------------------------ ? K ? DCR ? I L
R 1 + R 2
R 2
R 2 + R 1
I Load DCR
I AVG = -------------- ? ---------------
R ISEN
A simple R-C network across the inductor (R 1 , R 2 and C) extracts
the DCR voltage, as shown in Figure 6. The voltage across the
sense capacitor, V C , can be shown to be proportional to the
channel current I Ln , shown in Equation 6.
(EQ. 6)
? ? n
? s ? ----------------------- ? C + 1 ?
? ?
Where:
K = -------------------- (EQ. 7)
If the R-C network components are selected such that the RC
time constant matches the inductor L/DCR time constant (see
Equation 8), then V C is equal to the voltage drop across the DCR
14
current is then gained by 30%. The resulting cycle average
current, I AVG , provides a measure of the total load-current
demand on the converter during each switching cycle. Assuming
that the current in all the active channels is balanced, the
average sensed current can be calculated from Equation 10.
(EQ. 10)
N
In the ISL6328, the average scaled version of the load current,
I AVG , has a 100μA range. At 100μA, the Overcurrent Protection
maximum load current correlate to an average sensed current,
I AVG , of 80μA.
FN7621.1
June 7, 2011
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相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL6328IRZ-T | 功能描述:IC CTRLR PWM SYNC BUCK DL 48QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:2,000 系列:- 应用:控制器，DSP 输入电压:4.5 V ~ 25 V 输出数:2 输出电压:最低可调至 1.2V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:30-TFSOP（0.173"，4.40mm 宽） 供应商设备封装:30-TSSOP 包装:带卷 (TR) |
| ISL6329CRZ | 功能描述:电压模式 PWM 控制器 6+1 PHS DL PWM CONTRLR FOR CORE RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
| ISL6329CRZ-T | 功能描述:电压模式 PWM 控制器 6+1 PHS DL PWM CONTRLR FOR CORE RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
| ISL6329EVAL1Z | 制造商:Intersil Corporation 功能描述:ISL6329 EVALUATION BOARD - 60 LEAD - QFN - ROHS COMPLIANT - Bulk |
| ISL6329IRZ | 功能描述:电压模式 PWM 控制器 6+1 PHS DL PWM CONTRLR FOR CORE RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
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