參數(shù)資料
型號: MC44604P
廠商: ON SEMICONDUCTOR
元件分類: 穩(wěn)壓器
英文描述: RV Series - Econoline Unregulated DC-DC Converters; Input Voltage (Vdc): 3.3V; Output Voltage (Vdc): 3.3V; Power: 2W; High Isolation 2W Converter; Approved for Medical Applications; EN and UL Safety Certificates; 6kVDC Isolation; Skinny DIP24 Package; Optional Continuous Short Circuit Protected; Fully Encapsulated; Very Low Isolation Capacitance
中文描述: 0.75 A SWITCHING CONTROLLER, 250 kHz SWITCHING FREQ-MAX, PDIP16
封裝: PDIP-16
文件頁數(shù): 18/24頁
文件大?。?/td> 341K
代理商: MC44604P
MC44604
http://onsemi.com
18
The overvoltage section is enabled 5
μ
s after the regulator
has started to allow the reference Vref to stabilize.
By connecting external resistors to pin 6, the threshold
VCC level can be changed.
Figure 38. VCC Management
Reference Block:
Voltage and Current
Sources Generator
(Vref, Iref, ...)
Vref enable
CSTART–UP
1
0
1
0
Vdisable
7.5 V or
12.5 V
START–UP
14.5 V
UVLO1
(to SOFTSTART)
Vdisable1
9.0 V
CUVLO1
Rref
Pin 16
MC44604
VCC
(Pin 1)
Undervoltage Lockout Section
As depicted in Figure 39, an undervoltage lockout has
been incorporated to guarantee that the IC is fully functional
before allowing operation of the system.
Indeed, the VCC is connected to the non inverting input of
a comparator that has an upper threshold equal to 14,5 V
(Vstup–th) and a lower one equal to 7.5 V (Vdisable2) in
normal mode and 14.5 V and 12.5 V in Standby mode
(typical values) (Note 1).
This hysteresis comparator enables or disables the
reference block that generates the voltage and current
sources required by the system.
This block particularly, produces Vref (pin 16 voltage)
and Iref that is determined by the resistor Rref connected
between pin 16 and the ground:
Iref
Vref
Rref
where Vref
2.5 V (typically)
In addition to this, VCC is compared to a second threshold
level that is nearly equal to 9 V (Vdisable1) so that in normal
mode, a signal UVLO1 is generated to reset the maximum
duty cycle and soft–start block and so, to disable the output
stage (refer to Max. Duty Cycle and Soft–Start §) as soon as
VCC becomes lower than Vdisable1. In this way, the circuit is
reset and made ready for a next start–up, before the reference
block is disabled (refer to Figure 26). In standby, UVLO1 is
not active (there is no need to discharge the soft–start
capacitor as the soft–start pin is maintained short circuited).
Note 1. In standby the difference between Vdisable2 and
Vstup–th is decreased not to have too low pulsed mode
frequencies.
Thus, finally in normal mode, the upper Vcc limit that
enables the output to be active, is 9.4 V (maximum value of
Vdisable1) and so the minimum hysteresis is 4.2 V.
[(Vstup–th)min = 13.6 V].
The large hysteresis and the low start–up current of the
MC44604 make it ideally suited for off–line converter
applications where efficient bootstrap start–up techniques
are required.
Standby Management
The MC44604 has been designed to detect the transitions
between the standby and normal mode and to manage each
mode in an optimal way.
In standby, the device monitors a pulsed mode that enables
to drastically reduce the power consumption.
Pulsed Mode
The MC44604 standby is preferably associated to a
flyback configuration as depicted in Figure 39.
Figure 39. Standby Flyback Configuration
MC44604
Lp
VCC
Input
Voltage
P
Vstby
Regulator
1 0
1 = Standby
0 = Normal
Mode
In effect, by this means, all the output regulation levels are
divided by the ratio:
VHV
Vstby
where VHV is the normal mode high voltage regulation
level, Vstby is the standby
μ
P supply voltage.
For instance, in the case of TV or monitors applications,
the output levels (except the
μ
P supply voltage, Vstby) are
drastically reduced by a ratio in the range of 10.
Consequently, as the output voltages are reduced, the
losses due to the output leakage consumption, are practically
eliminated, without having to disconnect the loads.
Start–up Operations
The choice of the right configuration (normal or standby)
is performed at each start–up.
相關(guān)PDF資料
PDF描述
MC44605 High Safety, Latched Mode, GreenLine PWM Controller for (Multi)Synchronized Applications
MC44605P RW-S Series - Econoline Regulated DC-DC Converters; Input Voltage (Vdc): 05V; Output Voltage (Vdc): 05V; Power: 2W; DIP24 Low Profile Miniature Package; 1kVDC Isolation; Feedback Regulated Output; 2:1 Wide Range Voltage Input; Continuous Short Circuit Protection; Less than 7mm Height; SMD Pinning Option; Efficiency to 87%
MC44608P75 Few External Components Reliable Flexible GreenLine Very High Voltage PWM Controller
MC44608 Few External Components Reliable Flexible GreenLine Very High Voltage PWM Controller
MC44608P40 RW-S Series - Econoline Regulated DC-DC Converters; Input Voltage (Vdc): 05V; Output Voltage (Vdc): 09V; Power: 2W; DIP24 Low Profile Miniature Package; 1kVDC Isolation; Feedback Regulated Output; 2:1 Wide Range Voltage Input; Continuous Short Circuit Protection; Less than 7mm Height; SMD Pinning Option; Efficiency to 87%
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MC44604PG 功能描述:電流型 PWM 控制器 Voltage Mode PWM w/Bust Mode Standby RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時(shí)間: 下降時(shí)間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14
MC44605 制造商:ONSEMI 制造商全稱:ON Semiconductor 功能描述:High Safety, Latched Mode, GreenLine PWM Controller for (Multi)Synchronized Applications
MC44605_06 制造商:ONSEMI 制造商全稱:ON Semiconductor 功能描述:High Safety, Latched Mode, GreenLine TM PWM Controller for (Multi) Synchronized Applications
MC44605P 功能描述:電流型 PWM 控制器 Greenline PWM RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時(shí)間: 下降時(shí)間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14
MC44605PG 功能描述:電流型 PWM 控制器 ANA SMPS PWM FREQ CONT RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時(shí)間: 下降時(shí)間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14