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參數(shù)資料
| 型號： | NCP1501 |
| 廠商： | ON SEMICONDUCTOR |
| 英文描述： | Dual Mode PWM/Linear Buck Converter(雙模PWM/線性降壓轉(zhuǎn)換器) |
| 中文描述： | 雙模式PWM /線性降壓轉(zhuǎn)換器（雙模的PWM /線性降壓轉(zhuǎn)換器） |
| 文件頁數(shù)： | 5/14頁 |
| 文件大小： | 161K |
| 代理商： | NCP1501 |
NCP1501
http://onsemi.com
5
DETAILED OPERATING DESCRIPTION
The Buck regulator is a synchronous rectifier PWM
regulator with integrated MOSFETs. This regulator has an
LDO function for low power modes to conserve power and
lower ripple voltage associated with PFM mode. The
NCP1501 does not contain an internal oscillator for the
switching mode. The Dual PWM/LDO mode is an exclusive
Patent Pending circuit.
The PWM clock is generated via an external clock signal
on the Synchronization pin. The operating frequency range
for the PWM is 500 kHz to 1000 kHz. The output current of
the PWM is typically 100 mA with a guarantee of over
300 mA for the 2.7 to 5.2 input voltage range.
If a synchronization pulse is not present, the NCP1501
changes into the LDO mode. The LDO function assures the
user of an extremely low output ripple voltage and greatly
reduced quiescent current when the users system is in a sleep
mode. Internally to the NCP1501, the Synchronization pin
has a pull down resistor to force the part into LDO mode
when a clock signal is not present. To place the NCP1501 in
LDO mode, the user must set the Synchronization pin low.
The LDO mode guarantees an output in excess of 50 mA.
Pins CB0 and CB1 control the output voltage selection.
The four voltages are 1.05 V, 1.35 V, 1.57 V, 1.8 V. CB0
contains a pull down resistor and CB1 contains a pull up
resistor internal to the NCP1501. The resistors force the
output of the converter to 1.35 V if the pins are floating
connections to the external circuit.
The Shutdown Pin enables the operation of the device.
The Shutdown Pin has an internal pull down resistor to force
the NCP1501 into the off mode if this pin is floating due to
the external circuit. During Startup, the NCP1501 has a soft
start function to limit fast dV/dt and eliminate overshoot on
the output.
Figure 3. Block Diagram and Circuit Schematic of the NCP1501
L1
V
bat
Sync
SHD
C
in
10
DC/DC
CONTROL
LDO
CONTROL
Q2
EA
CB0
CB1
10 H
LX
FB
V
out
C
out
10
I
lim
Q1
Q3
The external components required are an input and an
output 10 0 F ceramic capacitor and a 10 H inductor.
PWM Mode
During normal operation, a synchronization pulse acts as
the clock for the DC/DC controller. The rising edge of the
clock pulls the gate of Q1 low allowing the inductor to
charge. When the current through Q1 reaches either the
current limit or feedback voltage reaches its limit, Q1 will
turn off and Q2 will turn on. Q2 replaces the free wheeling
diode typically associated with Buck Converters. Q2 will
turn off when either a rising edge sync pulse is present or all
the stored energy is depleted from the inductor. Q3 remains
off during this mode.
The output voltage accuracy in the PWM mode is well
within 3% of the nominal set value. An over voltage
protection circuit is present in the PWM mode to limit the
positive voltage spike due to fast load transient conditions.
The PWM also has the ability to go to 100% duty cycle for
transient conditions and low input to output voltage
differentials.
In PWM mode, each switching cycle has a guaranteed
ontime of 100 ns. The NCP1501 has two protection circuits
that can eliminate the cycle. When tripped, the over voltage
protection or the thermal shutdown overrides the gate drive
of the high side MOSFET.
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| NCP1508MNR2 | Up to 500 mA, 1 MHz, High Efficiency Synchronous Step−Down DC−DC Converter in DFN Package |
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| NCP1501DMR2 | 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 Dual Mode Buck w/LDO RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風格:SMD/SMT |
| NCP1501DMR2G | 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 Dual Mode Buck w/LDO RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風格:SMD/SMT |
| NCP1508MNR2 | 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 High Efficiency Buck RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風格:SMD/SMT |
| NCP1508MNR2G | 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 High Efficiency Buck Synchronous DC/DC RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風格:SMD/SMT |
| NCP1509MNR2 | 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 High Efficiency Buck RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風格:SMD/SMT |
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