参数资料
| 型号： | MC44605PG |
| 厂商： | ON Semiconductor |
| 文件页数： | 14/20页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR FLYBK ISO PWM 16DIP |
| 产品变化通告： | Product Obsolescence 19/Dec/2008 |
| 标准包装： | 500 |
| 系列： | GreenLine™ |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 250kHz |
| 占空比： | 80% |
| 电源电压： | 10 V ~ 15 V |
| 降压： | 无 |
| 升压： | 无 |
| 回扫： | 是 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 是 |
| 工作温度： | -25°C ~ 85°C |
| 封装/外壳： | 16-DIP（0.300"，7.62mm） |
| 包装： | 管件 |
| 其它名称： | MC44605PGOS |
MC44605
V ref
For instance, if this threshold value is required to be equal
τ Out
C OVLO
(V ref )
30
+ 7.5
r1 + 3
V CC
T
0
2.5 V
In
Delay τ 5.0 m s
Out
Enable
V OVP out
In
Delay
2.0 m s
2.5 V
(If V OVP out = 1.0,
the Output is Disabled)
to 30 V, V pin9 must be equal to 7.5 V when the
synchronization pulse value is 30 V.
So, in this case:
r2
r1 ) r2
Then, the ratio (r1/r2) can be deducted:
r2
So, as r1 and r2 must be negligible in relation to R (about
50 k W ), the couple of resistors can be chosen as follows:
r1 + 3 k Ω
and:
Figure 9. Overvoltage Protection
A delay (2 m s) is incorporated in order to avoid any
activation due to interferences by only taking into account
the overvoltages that last at least 2 m s.
The V CC is connected when once the circuit has
started ? up in order to limit the circuit startup consumption
(T is switched on when once V ref has been generated).
The overvoltage section is enabled 5 m s after the regulator
has started to allow the reference V ref to stabilize.
r2 + 1 k Ω
Winding Short Circuit Detection Section (WSCD)
The MC44605 being designed to control a Fly ? Back
SMPS, this block is incorporated to detect a short circuit on
a transformer winding or on an output diode (refer to
Figure 11).
+
E.H.T. Overvoltage Protection Section
This block uses the synchronization input as this section
AC Line
+
L p
+
is incorporated to detect too high synchronization pulses and
then to activate the device definitive latch in this case.
L leak
Synchro.
Pulses
V CC
Synchronization
MC44605
R S
Negative Active
Block
r1
Pin 9
r2
Clamping System
2R
C EHTOVP
Disabling
Block
E.H.T.
Figure 11. Winding Short Circuit Fault
In the case of a Winding Short Circuit, the primary
4V
R
V ref
OVP
inductor L p is short circuited and then the current increase
is only controlled by the leakage inductor L leak .
In current mode, the power switch conduction is stopped
Figure 10. E.H.T. OVP
MC44605
when the inductor current is detected as high enough, by the
controller. In fact, when the current sense resistor (R s )
voltage gets equal to V cs , the current sense comparator
switches to reset the output.
This block consists of a high impedance resistors bridge
(R is nearly equal to 50 k W ? refer to Figure 10) so that the
EHTovp threshold is 7.5 V. So, using an external resistors
bridge (r1, r2 <<R), the synchronization pulse level above
which the working must be considered as wrong, can be
Now, the circuit has a propagation delay and the power
switch needs some time to turn off. Consequently, there is a
delay D t between the moment at which the R s voltage gets
equal to V cs and the actual current increase stop. So, this
results in an overcurrent (refer to Figure 12).
adjusted.
http://onsemi.com
14
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相关代理商/技术参数 |
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| MC44608 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Few External Components Reliable Flexible GreenLine Very High Voltage PWM Controller |
| MC44608_06 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Few External Components Reliable and Flexible SMPS Controller |
| MC44608P100 | 功能描述:IC REG CTRLR FLYBK ISO PWM 8-DIP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:4,000 系列:- 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:-40°C ~ 85°C 封装/外壳:40-VFQFN 裸露焊盘 包装:带卷 (TR) |
| MC44608P40 | 功能描述:电压模式 PWM 控制器 40KHz High Voltage RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
| MC44608P40G | 功能描述:电压模式 PWM 控制器 40KHz High Voltage SMPS PWM RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
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