参数资料
| 型号： | ISL6565BCV-T |
| 厂商： | Intersil |
| 文件页数： | 11/28页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM VM 28TSSOP |
| 标准包装： | 2,500 |
| PWM 型： | 电压模式 |
| 输出数： | 1 |
| 频率 - 最大： | 1.5MHz |
| 占空比： | 66.7% |
| 电源电压： | 4.75 V ~ 5.25 V |
| 降压： | 是 |
| 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： | 0°C ~ 105°C |
| 封装/外壳： | 28-TSSOP（0.173"，4.40mm 宽） |
| 包装： | 带卷 (TR) |
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ISL6565A, ISL6565B
Figures 19 and 20 in the section entitled Input Capacitor
Selection can be used to determine the input-capacitor RMS
current based on load current, duty cycle, and the number of
channels. They are provided as aids in determining the
optimal input capacitor solution.
PWM Operation
The timing of each converter leg is set by the number of
active channels. The default channel setting for the
ISL6565A, ISL6565B is three. One switching cycle is defined
as the time between PWM1 pulse termination signals. The
pulse termination signal is the internally generated clock
signal that triggers the falling edge of PWM1. The cycle time
of the pulse termination signal is the inverse of the switching
frequency set by the resistor between the FS pin and
ground. Each cycle begins when the clock signal commands
PWM1 to go low. The PWM1 transition signals the channel-1
MOSFET driver to turn off the channel-1 upper MOSFET
The sampled current, at the end of the t SAMPLE , is
proportional to the inductor current and is held until the next
switching period sample. The sampled current is used for
current balance, load-line regulation, and overcurrent
protection.
I L
PWM
I SEN
t SAMPL E
and turn on the channel-1 synchronous MOSFET. In the
default channel configuration, the PWM2 pulse terminates
OLD SAMPLE
CURRENT
NEW SAMPLE CURRENT
I n = I L ---------------------- )
1/3 of a cycle after the PWM1 pulse. The PWM3 pulse
terminates 1/3 of a cycle after PWM2.
If PWM3 is connected to VCC, two channel operation is
selected and the PWM2 pulse terminates 1/2 of a cycle after
the PWM1 pulse terminates.
Once a PWM pulse transitions low, it is held low for a
minimum of 1/3 cycle. This forced off time is required to
ensure an accurate current sample. Current sensing is
described in the next section. After the forced off time
expires, the PWM output is enabled. The PWM output state
is driven by the position of the error amplifier output signal,
V COMP , minus the current correction signal relative to the
sawtooth ramp as illustrated in Figure 6. When the modified
V COMP voltage crosses the sawtooth ramp, the PWM output
transitions high. The MOSFET driver detects the change in
state of the PWM signal and turns off the synchronous
MOSFET and turns on the upper MOSFET. The PWM signal
will remain high until the pulse termination signal marks the
beginning of the next cycle by triggering the PWM signal low.
Current Sampling
During the forced off-time, following a PWM transition low,
the current-sense amplifier uses the ISEN inputs to
reproduce a signal proportional to the inductor current, I L .
No matter which current-sense method is employed, the
sense current (I SEN ) is simply a scaled version of the
inductor current. The sample window opens exactly 1/6 of
the switching period, t SW , after the PWM transitions low. The
sample window then stays open for a fixed amount of time,
t SAMPLE , and is equal to 1/6 of the switching period, t SW as
illustrated in Figure 3.
SWITCHING PERIOD
TIME
FIGURE 3. SAMPLE AND HOLD TIMING
Current Sensing
The ISL6565A supports MOSFET r DS(ON) current sensing,
while the ISL6565B supports inductor DCR current sensing.
The internal circuitry, shown in Figures 4 and 5, represent
channel n of an N-channel converter. This circuitry is
repeated for each channel in the converter, but may not be
active depending on the status of the PWM3 pin, as
described in the PWM Operation section.
MOSFET r DS(ON) SENSING (ISL6565A ONLY)
The ISL6565A senses the channel load current by sampling
the voltage across the lower MOSFET r DS(ON) , as shown in
Figure 4. A ground-referenced operational amplifier, internal
to the ISL6565A, is connected to the PHASE node through a
resistor, R ISEN . The voltage across R ISEN is equivalent to
the voltage drop across the r DS(ON) of the lower MOSFET
while it is conducting. The resulting current into the ISEN pin
is proportional to the channel current, I L . The ISEN current is
sampled and held as described in the Current Sampling
section. From Figure 4, the following equation for I n is
derived where I L is the channel current.
r DS ( ON (EQ. 4)
R ISEN
t SW 1
6 ? f SW
t SAMPLE = ---------- = ------------------
6
11
(EQ. 3)
FN9135.4
December 1, 2005
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相关代理商/技术参数 |
参数描述 |
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| ISL6565BCVZ | 功能描述:IC REG CTRLR BUCK PWM VM 28TSSOP 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) |
| ISL6565BCVZ-T | 功能描述:IC REG CTRLR BUCK PWM VM 28TSSOP 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) |
| ISL6566ACRZ | 功能描述:IC CTRLR PWM 3PHASE BUCK 40-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
| ISL6566ACRZ-T | 功能描述:IC CTRLR PWM 3PHASE BUCK 40-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
| ISL6566AIRZ | 功能描述:IC CTRLR PWM 3PHASE BUCK 40-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
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