参数资料
型号: ISL9440AIRZ
厂商: Intersil
文件页数: 17/20页
文件大小: 0K
描述: IC REG QD BCK/LINEAR SYNC 32-QFN
产品培训模块: Patient Monitoring and Diagnostic Equipment Solutions
Solutions for Test and Measurement Equipment
Solutions for Industrial Control Applications
标准包装: 60
拓扑: 降压(降压)同步(3),线性(LDO)(1)
功能: 任何功能
输出数: 4
频率 - 开关: 600kHz
电压/电流 - 输出 1: 控制器
电压/电流 - 输出 2: 控制器
电压/电流 - 输出 3: 控制器
带 LED 驱动器:
带监控器:
带序列发生器:
电源电压: 4.5 V ~ 24 V
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 32-VFQFN 裸露焊盘
供应商设备封装: *
包装: 管件
产品目录页面: 1244 (CN2011-ZH PDF)
ISL9440, ISL9440A, ISL9441
( I O ) ( r DS ( ON ) ) ( V OUT )
( I O ) ( V IN ) ( t SW ) ( F SW )
P UPPER = --------------------------------------------------------------- + ------------------------------------------------------------
V IN
( I O ) ( r DS ( ON ) ) ( V IN – V OUT )
P LOWER = -------------------------------------------------------------------------------
requirements determine the maximum base-to-emitter
capacitance.
Layout Guidelines
Careful attention to layout requirements is necessary for
successful implementation of an ISL9440, ISL9440A and
ISL9441 based DC/DC converter. The ISL9440, ISL9440A
and ISL9441 switch at a very high frequency and therefore
the switching times are very short. At these switching
frequencies, even the shortest trace has significant
impedance. Also, the peak gate drive current rises
significantly in extremely short time. Transition speed of the
current from one device to another causes voltage spikes
across the interconnecting impedances and parasitic circuit
elements. These voltage spikes can degrade efficiency,
generate EMI, increase device overvoltage stress and
ringing. Careful component selection and proper PC board
layout minimizes the magnitude of these voltage spikes.
There are three sets of critical components in a DC/DC
converter using the ISL9440, ISL9440A and ISL9441: The
controller, the switching power components and the small
signal components. The switching power components are
the most critical from a layout point of view because they
switch a large amount of energy so they tend to generate a
large amount of noise. The critical small signal components
are those connected to sensitive nodes or those supplying
critical bias currents. A multi-layer printed circuit board is
recommended.
Layout Considerations
1. The Input capacitors, Upper FET, Lower FET, Inductor
and Output capacitor should be placed first. Isolate these
power components on the topside of the board with their
ground terminals adjacent to one another. Place the input
high frequency decoupling ceramic capacitor very close
to the MOSFETs.
2. Use separate ground planes for power ground and small
signal ground. Connect the SGND and PGND together
close to the IC. Do not connect them together anywhere
else.
3. The loop formed by Input capacitor, the top FET and the
bottom FET must be kept as small as possible.
4. Ensure the current paths from the input capacitor to the
MOSFET, to the output inductor and output capacitor are
as short as possible with maximum allowable trace
widths.
5. Place The PWM controller IC close to lower FET. The
LGATE connection should be short and wide. The IC can
be best placed over a quiet ground area. Avoid switching
ground loop current in this area.
6. Place VCC_5V bypass capacitor very close to VCC_5V
pin of the IC and connect its ground to the PGND plane.
7. Place the gate drive components BOOT diode and BOOT
capacitors together near controller IC
17
8. The output capacitors should be placed as close to the
load as possible. Use short wide copper regions to
connect output capacitors to load to avoid inductance and
resistances.
9. Use copper filled polygons or wide but short trace to
connect the junction of upper FET, Lower FET and output
inductor. Also keep the PHASE node connection to the IC
short. Do not unnecessarily oversize the copper islands
for PHASE node. Since the phase nodes are subjected to
very high dv/dt voltages, the stray capacitor formed
between these islands and the surrounding circuitry will
tend to couple switching noise.
10. Route all high speed switching nodes away from the
control circuitry.
11. Create a separate small analog ground plane near the IC.
Connect the SGND pin to this plane. All small signal
grounding paths including feedback resistors, current
limit setting resistors and ENx pull-down resistors should
be connected to this SGND plane.
12. Ensure the feedback connection to the output capacitor is
short and direct.
Component Selection Guidelines
MOSFET Considerations
The logic level MOSFETs are chosen for optimum efficiency
given the potentially wide input voltage range and output
power requirements. Two N-Channel MOSFETs are used in
each of the synchronous-rectified buck converters for the 3
PWM outputs. These MOSFETs should be selected based
upon r DS(ON) , gate supply requirements, and thermal
management considerations.
The power dissipation includes two loss components;
conduction loss and switching loss. These losses are
distributed between the upper and lower MOSFETs
according to duty cycle (see the following equations). The
conduction losses are the main component of power
dissipation for the lower MOSFETs. Only the upper MOSFET
has significant switching losses, since the lower device turns
on and off into near zero voltage. The equations assume
linear voltage-current transitions and do not model power
loss due to the reverse-recovery of the lower MOSFET’s
body diode.
2
2
(EQ. 10)
2
(EQ. 11)
V IN
A large gate-charge increases the switching time, t SW , which
increases the upper MOSFET switching losses. Ensure that
both MOSFETs are within their maximum junction
temperature at high ambient temperature by calculating the
temperature rise according to package thermal-resistance
specifications.
FN6383.1
December 5, 2007
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ISL9440AIRZ-T 功能描述:IC REG QD BCK/LINEAR SYNC 32-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 线性 + 切换式 系列:- 标准包装:2,500 系列:- 拓扑:降压(降压)同步(2),线性(LDO)(1) 功能:任何功能 输出数:3 频率 - 开关:300kHz 电压/电流 - 输出 1:控制器 电压/电流 - 输出 2:控制器 电压/电流 - 输出 3:控制器 带 LED 驱动器:无 带监控器:无 带序列发生器:是 电源电压:4.5 V ~ 24 V 工作温度:-40°C ~ 85°C 安装类型:* 封装/外壳:28-TSSOP(0.173",4.40mm 宽) 供应商设备封装:* 包装:带卷 (TR) 其它名称:ISL6402IVZ-TTR
ISL9440BEVAL1Z 功能描述:EVAL BOARD 1 FOR ISL9440B RoHS:是 类别:编程器,开发系统 >> 评估板 - DC/DC 与 AC/DC(离线)SMPS 系列:* 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:True Shutdown™ 主要目的:DC/DC,步升 输出及类型:1,非隔离 功率 - 输出:- 输出电压:- 电流 - 输出:1A 输入电压:2.5 V ~ 5.5 V 稳压器拓扑结构:升压 频率 - 开关:3MHz 板类型:完全填充 已供物品:板 已用 IC / 零件:MAX8969
ISL9440BIRZ 功能描述:IC REG QD BCK/LINEAR SYNC 32-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 线性 + 切换式 系列:- 标准包装:2,500 系列:- 拓扑:降压(降压)同步(2),线性(LDO)(1) 功能:任何功能 输出数:3 频率 - 开关:300kHz 电压/电流 - 输出 1:控制器 电压/电流 - 输出 2:控制器 电压/电流 - 输出 3:控制器 带 LED 驱动器:无 带监控器:无 带序列发生器:是 电源电压:4.5 V ~ 24 V 工作温度:-40°C ~ 85°C 安装类型:* 封装/外壳:28-TSSOP(0.173",4.40mm 宽) 供应商设备封装:* 包装:带卷 (TR) 其它名称:ISL6402IVZ-TTR
ISL9440BIRZ-T 功能描述:IC REG QD BCK/LINEAR SYNC 32-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 线性 + 切换式 系列:- 标准包装:2,500 系列:- 拓扑:降压(降压)同步(2),线性(LDO)(1) 功能:任何功能 输出数:3 频率 - 开关:300kHz 电压/电流 - 输出 1:控制器 电压/电流 - 输出 2:控制器 电压/电流 - 输出 3:控制器 带 LED 驱动器:无 带监控器:无 带序列发生器:是 电源电压:4.5 V ~ 24 V 工作温度:-40°C ~ 85°C 安装类型:* 封装/外壳:28-TSSOP(0.173",4.40mm 宽) 供应商设备封装:* 包装:带卷 (TR) 其它名称:ISL6402IVZ-TTR
ISL9440CEVAL1Z 功能描述:EVAL BOARD 1 FOR ISL9440C RoHS:是 类别:编程器,开发系统 >> 评估板 - DC/DC 与 AC/DC(离线)SMPS 系列:* 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:True Shutdown™ 主要目的:DC/DC,步升 输出及类型:1,非隔离 功率 - 输出:- 输出电压:- 电流 - 输出:1A 输入电压:2.5 V ~ 5.5 V 稳压器拓扑结构:升压 频率 - 开关:3MHz 板类型:完全填充 已供物品:板 已用 IC / 零件:MAX8969