参数资料
型号: MC33368P
厂商: ON Semiconductor
文件页数: 9/16页
文件大小: 228K
描述: IC CTRLR PFC HI VOLTAGE 16DIP
产品变化通告: LTB Notification 03/Jan/2008
标准包装: 25
系列: GreenLine™
模式: 临界传导(CRM)
电流 - 启动: 16mA
电源电压: 10 V ~ 16 V
工作温度: -25°C ~ 125°C
安装类型: 通孔
封装/外壳: 16-DIP(0.300",7.62mm)
供应商设备封装: 16-DIP
包装: 管件
其它名称: MC33368POS
MC33368
http://onsemi.com
9
In this manner, the SMPS switching transistors are operated
at very low duty cycles, preventing their destruction. If the
short circuit fault is removed, the power supply system will
turn on by itself in a normal startup mode after the restart
delay has timed out.
Output Switching Frequency Clamp
In normal operation, the MC33368 operates the boost
inductor in the critical mode. That is, the inductor current
ramps to a peak value, ramps down to zero, then
immediately begins ramping positive again. The peak
current is programmed by the multiplier output within the
IC. As the input voltage haversine declines to near zero, the
output switch ontime becomes constant, rather than going
to zero because of the small integrated dc voltage at Pin 5
caused by C2, R3 and R5. Because of this, the average line
current does not exactly follow the line voltage near the zero
crossings. The Output Switching Frequency Clamp
remedies this situation to improve power factor and
minimize EMI generated in this operating region. The
values of R10 and C7, as shown in Figure 16, program a
minimum offtime in the frequency clamp which overrides
the zero current detect signal, forcing a minimum offtime.
This allows discontinuous conduction operation of the boost
inductor in the zero crossing region, and the average line
current more nearly follows the voltage. The Output
Switching Frequency Clamp function can be disabled by
connecting the FC input, Pin 13, to the V
CC
 supply Pin 12.
For best results, the minimum offtime, determined by the
values of R10 and C7, should be chosen so that t
s(min)
 = t
(on)
+ t
(off)fc
. Output drive is inhibited when the voltage at the
frequency clamp input is less than 2.0 V. When the output
drive is high, C7 is discharged through an internal 100 mA
current source. When the output drive switches low, C7 is
charged through R10. The drive output is inhibited until the
voltage across C7 reaches 2.0 V, establishing a minimum
offtime where:
t
(off)fc
+  *  R10 C7 log
e
1 *
2
V
CC
Output
The IC contains a CMOS output driver that was
specifically designed for direct drive of power MOSFETs.
The Gate Output is capable of up to ?500 mA peak current
with a typical rise and fall time of 50 ns with a 1.0 nF load.
Additional internal circuitry has been added to keep the Gate
Output in a sinking mode whenever the Undervoltage
Lockout is active. This characteristic eliminates the need for
an external gate pulldown resistor. The totempole output
has been optimized to minimize crossconduction current
during high speed operation.
相关PDF资料
PDF描述
VE-J0W-IZ CONVERTER MOD DC/DC 5.5V 25W
GMC49DREI-S734 CONN EDGECARD 98POS .100 EYELET
MC33368DR2 IC CTRLR PFC HI VOLTAGE 16SOIC
NCP582DSQ15T1G IC REG LDO 1.5V .15A SC82AB
T95R127K020LZAL CAP TANT 120UF 20V 10% 2824
相关代理商/技术参数
参数描述
MC33368PG 功能描述:功率因数校正 IC High Voltage PFC w/Critical Mode RoHS:否 制造商:Fairchild Semiconductor 开关频率:300 KHz 最大功率耗散: 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Reel
MC33375D-2.5 功能描述:低压差稳压器 - LDO 2.5V 300mA RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压(最大值):307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20
MC33375D-2.5G 功能描述:低压差稳压器 - LDO 2.5V 300mA RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压(最大值):307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20
MC33375D-2.5R2 功能描述:低压差稳压器 - LDO 2.5V 300mA RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压(最大值):307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20
MC33375D-2.5R2G 功能描述:低压差稳压器 - LDO 2.5V 300mA RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压(最大值):307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20