参数资料
| 型号： | ISL6742AAZA-T |
| 厂商： | Intersil |
| 文件页数： | 16/18页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR PWM CM/VM 16-QSOP |
| 标准包装： | 1 |
| PWM 型： | 电流/电压模式 |
| 输出数： | 4 |
| 频率 - 最大： | 2MHz |
| 占空比： | 100% |
| 电源电压： | 9 V ~ 16 V |
| 降压： | 无 |
| 升压： | 无 |
| 回扫： | 无 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 105°C |
| 封装/外壳： | 16-SSOP（0.154"，3.90mm 宽） |
| 包装： | 剪切带 (CT) |
| 其它名称： | ISL6742AAZA-TCT |
ISL6742
Figure 15 illustrates a master-slave current sharing method.
VOLTAGE ERROR
AMPLIFIER INVERTING (-)
distribution drops between the power supply outputs and the
remote sensing location. The current limit circuit must limit the
voltage change to less than the output overvoltage threshold
U1
INPUT
BIAS
or an overvoltage condition can be induced.
1
2
3
4
16
ISL6742 15
VDD 14
13
Amplifier U2A sets the scaling factor from IOUT to IShare
and increases the current sourcing capability of IShare. U2B
is a low bandwidth amplifier that sets the frequency
5
6
7 CS
8 IOUT
S&H
4x
12
11
10
9
R2
(>>R1)
C1
OUTPUT
VOUT
response and gain of the current share circuitry. The current
share bandwidth must be much lower than the voltage
feedback loop bandwidth to ensure overall stability. The gain
VOLTAGE
is set by R1 and R5, and the bandwidth by R5 and C1.
+
U2A
-
R1
R5
(>>R1)
FEEDBACK
DIVIDER
The disconnect in series with IShare may be omitted for
power systems that do not require fault isolation. The
R3
-
U2B
Q1
R7
disconnect switch is normally implemented with MOSFET or
R4
+
JFET devices.
(>>R3)
R6
Average Current Mode Control
The average current signal produced on IOUT may also be
used for average current mode control rather than peak
current mode control. There are many advantages to
DISCONNECT IF P/S FAILS
ISHARE
average current mode control, most notably, improved noise
OR IS TURNED OFF
FIGURE 15. MASTER-SLAVE CURRENT SHARING USING
AVERAGE CURRENT
immunity and greater design flexibility of the current
feedback loop compensation. Figure 16 portrays the
concept.
In parallel and redundant applications, the IShare signals
C2
R3
IOUT
R2
VOUT
C1
from each power supply are connected together. Each
power supply produces a voltage proportional to its average
-
R4
OFFSET
R1
output current on IOUT, and through limiting resistor R3, on
IShare. The unit with the highest IShare signal (and highest
output current) sources current onto the IShare Bus, and is
identified as the master unit. The units with lower IShare
signals do not source current onto IShare, and are identified
VERR
U2
+
CURRENT
ERROR
AMPLIFIER
-
U1
+ REF
VOLTAGE ERROR
AMPLIFIER
Rb
as slave units. Each slave unit compares the master ’s
IShare signal with its own, and if there is sufficient difference,
turns Q1 on, which pulls down on the feedback voltage.
Reducing the feedback voltage causes the output voltage to
appear low; the feedback loop compensates by increasing
the output voltage, and the output current increases. Each
slave unit will increase its output voltage until its output
current is nearly equal to that of the master.
The difference between the master’s output current and that of
a slave unit is set by R1 and R2. Some difference is required to
prevent undesirable switching of master and slave roles. This
difference also prevents operation of the current sharing
circuitry when a power supply is operating stand alone.
The maximum output voltage that a slave can induce in its
output is controlled by R6 and the output voltage feedback
divider. Typically, the maximum allowed output voltage
increase is limited to a few percent, but must be greater than
the tolerance of the feedback and reference components and
any distribution drops between units. If remote sensing is
used, the adjustment range must also include the difference in
16
FIGURE 16. AVERAGE CURRENT MODE CONTROL
Instead of being compared to a peak current sense signal as
it would be in a peak current mode control configuration, the
voltage amplifier output is integrated against the average
output current. The voltage loop compensation and the
current loop compensation may be adjusted independently.
The voltage error amplifier programs the average output
current of the supply, and its maximum output level
determines the maximum output current. Either IOUT or the
voltage EA output must be scaled appropriately to achieve
the desired current limit setpoint. The offset voltage shown in
Figure 16 must be provided to compensate for input offset
voltage of the current amplifier to ensure that zero duty cycle
operation is achievable.
Depending on the performance requirements of the control
loop, compensation networks other than shown may be
required.
FN9183.2
October 31, 2008
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PDF描述 |
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| ISL6744AABZ | IC REG CTRLR PWM VM 8-SOIC |
| ISL6744AU-T | IC REG CTRLR BUCK PWM VM 8-MSOP |
| ISL6745AAUZ | IC REG CTRLR PWM VM 10-MSOP |
| ISL6745AU-T | IC REG CTRLR PWM VM 10-MSOP |
| ISL6752AAZA-T | IC REG CTRLR PWM CM 16-QSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL6744AABZ | 功能描述:IC REG CTRLR PWM VM 8-SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:275kHz 占空比:50% 电源电压:18 V ~ 110 V 降压:无 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:-40°C ~ 85°C 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) |
| ISL6744AABZ-T | 功能描述:IC REG CTRLR PWM VM 8-SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:275kHz 占空比:50% 电源电压:18 V ~ 110 V 降压:无 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:-40°C ~ 85°C 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) |
| ISL6744AAUZ | 功能描述:IC REG CTRLR PWM VM 8-MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:275kHz 占空比:50% 电源电压:18 V ~ 110 V 降压:无 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:-40°C ~ 85°C 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) |
| ISL6744AAUZ-T | 功能描述:IC REG CTRLR PWM VM 8-MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:275kHz 占空比:50% 电源电压:18 V ~ 110 V 降压:无 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:-40°C ~ 85°C 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) |
| ISL6744AB | 功能描述:电压模式 PWM 控制器 Intermediate Bus 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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