参数资料
型号: NCP5422ADR2
厂商: ON Semiconductor
文件页数: 8/16页
文件大小: 0K
描述: IC REG CTRLR BUCK PWM 16-SOIC
产品变化通告: Product Obsolescence 11/Feb/2009
标准包装: 2,500
PWM 型: 电流/电压模式,V²?
输出数: 1
频率 - 最大: 750kHz
占空比: 100%
电源电压: 10.8 V ~ 13.2 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: 0°C ~ 70°C
封装/外壳: 16-SOIC(0.154",3.90mm 宽)
包装: 带卷 (TR)
其它名称: NCP5422ADR2OS
NCP5422A
0.40 V PWM comparator offset threshold and the artificial
ramp, the PWM comparator terminates the initial pulse.
instantaneously, regulation is maintained by the output
capacitors during the time required to slew the inductor
current. For better transient response, several high
8.6 V
0.45 V
V IN
V COMP
V FB
GATE(H)1
frequency and bulk output capacitors are usually used.
Out-of-Phase Synchronization
In out-of-phase synchronization, the turn-on of the
second channel is delayed by half the switching cycle. This
delay is supervised by the oscillator, which supplies a clock
signal to the second channel which is 180 ° out of phase with
the clock signal of the first channel.
The advantages of out-of-phase synchronization are
many. Since the input current pulses are interleaved with one
UVLO
STARTUP
t S
NORMAL OPERATION
GATE(H)2
another, the overlap time is reduced. The effect of this
overlap reduction is to reduce the input filter requirement,
allowing the use of smaller components. In addition, since
Figure 4. Idealized Waveforms
Normal Operation
During normal operation, the duty cycle of the gate drivers
remains approximately constant as the V 2 control loop
maintains the regulated output voltage under steady state
conditions. Variations in supply line or output load
conditions will result in changes in duty cycle to maintain
regulation.
Gate Charge Effect on Switching Times
When using the onboard gate drivers, the gate charge has
an important effect on the switching times of the FETs. A
finite amount of time is required to charge the effective
capacitor seen at the gate of the FET. Therefore, the rise and
fall times rise linearly with increased capacitive loading,
according to the following graphs.
peak current occurs during a shorter time period, emitted
EMI is also reduced, thereby reducing shielding
requirements.
Overvoltage Protection
Overvoltage Protection (OVP) is provided as a result of
the normal operation of the V 2 control method and requires
no additional external components. The control loop
responds to an overvoltage condition within 150 ns, turning
off the upper MOSFET and disconnecting the regulator
from its input voltage. This results in a crowbar action to
clamp the output voltage preventing damage to the load. The
regulator remains in this state until the overvoltage
condition ceases.
Hiccup Overcurrent Protection
A lossless hiccup mode short circuit protection feature is
provided on the chip. The only external component required
90
80
70
60
50
40
30
Average Fall Time
Average Rise Time
is the COMP1 capacitor. Any overcurrent condition results
in the immediate shutdown of both output phases. Both the
upper and lower gate drives are driven low, turning off both
MOSFETs.
A comparator between the IS+ and IS- on each output
phase detects a short circuit when the voltage difference
between the two pins exceeds 70 mV and sets the fault latch.
The fault latch immediately turns off the error amplifier and
20
10
0
0
1
2
3
4
5
6
7
8
discharges both COMP capacitors. The capacitor connected
to COMP1 is discharged through a 5.0 m A current sink in
order to provide timing for the reset cycle. When COMP1
has fallen below 0.25 V, a comparator resets the fault latch
Load (nF)
Figure 5. Average Rise and Fall Times
Transient Response
The 150 ns reaction time of the control loop provides fast
transient response to any variations in input voltage and
output current. Pulse-by-pulse adjustment of duty cycle is
provided to quickly ramp the inductor current to the required
level. Since the inductor current cannot be changed
and error amplifier 1 begins to charge COMP1 with a 30 m A
source current. When COMP1 exceeds the feedback voltage
plus the PWM Comparator offset voltage, the normal
switching cycle will resume.
If the short circuit condition persists through the restart
cycle, the overcurrent reset cycle will repeat itself until the
short circuit is removed, resulting in small hiccup output
pulses while the COMP capacitor charges, as shown in
Figure 6.
http://onsemi.com
8
相关PDF资料
PDF描述
NCP5424DR2G IC REG CTRLR BUCK PWM 16-SOIC
NCP5425DB IC REG CTRLR BUCK PWM VM 20TSSOP
NCP5501DT50RKG IC REG LDO 5V .5A DPAK
NCP5666DS50R4G IC REG LDO 5V 3A D2PAK-5
NCP5667DS50R4G IC REG LDO 5V 3A D2PAK-5
相关代理商/技术参数
参数描述
NCP5422ADR2G 功能描述:DC/DC 开关控制器 Dual Out-Of-Phase Synchronous Buck RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK
NCP5422EVB 功能描述:电源管理IC开发工具 ANA SW REG EVAL BRD RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
NCP5423 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Dual Out−of−Phase Synchronous Buck Controller with Current Limit
NCP5423DR2G 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Dual Out−of−Phase Synchronous Buck Controller with Current Limit
NCP5424 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Dual Synchronous Buck Controller with Input Current Sharing