参数资料
| 型号： | ISL95872HRUZ-T |
| 厂商： | Intersil |
| 文件页数： | 12/17页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM 16UTQFN |
| 标准包装： | 3,000 |
| PWM 型： | R4 |
| 输出数： | 1 |
| 频率 - 最大： | 300kHz |
| 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： | -10°C ~ 100°C |
| 封装/外壳： | 16-UFQFN |
| 包装： | 带卷 (TR) |
ISL95872
V O
F SW ? L
transient currents within the devices in response to high dv/dt
switching present at the phase node. The drain-gate charge in
particular can conduct sufficient current through the driver pull-
down resistance that the V GS(th) of the device can be exceeded
and turned on. For this reason, the LGATE driver has been
designed with low pull-down resistance and high sink current
capability to ensure clamping the MOSFETs gate voltage below
V GS(th) .
Adaptive Shoot-Through Protection
Adaptive shoot-through protection prevents a gate-driver output
from turning on until the opposite gate-driver output has fallen
below approximately 1V. The dead-time shown in Figure 14 is
extended by the additional period that the falling gate voltage
remains above the 1V threshold. The high-side gate-driver output
voltage is measured across the UGATE and PHASE pins while the
low-side gate-driver output voltage is measured across the LGATE
and PGND pins. The power for the LGATE gate-driver is sourced
directly from the PVCC pin. The power for the UGATE gate-driver is
supplied by a boot-strap capacitor connected across the BOOT
and PHASE pins. The capacitor is charged each time the phase
node voltage falls a diode drop below PVCC such as when the
low-side MOSFET is turned on.
UGATE
General Application Design
Guide
This design guide is intended to provide a high-level explanation of
the steps necessary to design a single-phase buck converter. It is
assumed that the reader is familiar with many of the basic skills
and techniques referenced in the following. In addition to this
guide, Intersil provides complete reference designs that include
schematics, bill of materials, and example board layouts.
Selecting the LC Output Filter
The duty cycle of an ideal buck converter is a function of the
input and the output voltage. This relationship is expressed in
Equation 9:
D = --------- (EQ. 9)
V IN
The output inductor peak-to-peak ripple current is expressed in
Equation 10:
V O ? ( 1 – D )
I P-P = ------------------------------- (EQ. 10)
A typical step-down DC/DC converter will have an I PP of 20% to
40% of the maximum DC output load current. The value of I P-P is
selected based upon several criteria such as MOSFET switching
loss, inductor core loss, and the resistive loss of the inductor
winding. The DC copper loss of the inductor can be estimated
using Equation 11:
P COPPER = I LOAD ? DCR
1V
1V
2
(EQ. 11)
Where, I LOAD is the converter output DC current.
The copper loss can be significant so attention has to be given to
the DCR of the inductor. Another factor to consider when
1V
1V
choosing the inductor is its saturation characteristics at elevated
temperature. A saturated inductor could cause destruction of
LGATE
FIGURE 14. GATE DRIVE ADAPTIVE SHOOT-THROUGH PROTECTION
circuit components, as well as nuisance OCP faults.
A DC/DC buck regulator must have output capacitance C O into
which ripple current I P-P can flow. Current I P-P develops a
corresponding ripple voltage V P-P across C O, which is the sum of
the voltage drop across the capacitor ESR and of the voltage
change stemming from charge moved in and out of the
capacitor. These two voltages are expressed in Equations 12
and 13:
Δ V C = ---------------------------------
12
Δ V ESR = I P-P ? E SR
I P-P
8 ? C O ? F SW
(EQ. 12)
(EQ. 13)
FN7974.0
January 26, 2012
相关PDF资料 |
PDF描述 |
|---|---|
| ISL95874IRUZ-T | IC CTRLR PWM 1PHASE GPU 16UTQFN |
| ISL97516IUZ | IC REG BOOST ADJ 1A 8MSOP |
| ISL97519AIUZ-TK | IC REG BOOST ADJ 1A 8MSOP |
| ISL97519IUZ-T | IC REG BOOST ADJ 1A 8MSOP |
| ISL97522IRZ-TK | IC SUPPLY CTRL 4CH TFT-LCD 38QFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL95873HRUZ-T | 功能描述:电流型 PWM 控制器 2-Bit PWM GPU Controller for Toshiba. Spin of ISL95872; 2.6 RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| ISL95874HRUZ-T | 功能描述:电流型 PWM 控制器 0/2 BIT PWM GPU CONTLR FOR NOTEBOOK RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| ISL95874IRUZ-T | 功能描述:电流型 PWM 控制器 0/2 BIT PWM GPU CONTLR FOR NOTEBOOK RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| ISL95875HRUZ-T | 功能描述:电流型 PWM 控制器 RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| ISL95875IRUZ-T | 功能描述:电流型 PWM 控制器 RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
发布紧急采购，3分钟左右您将得到回复。