- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄379820 > CD54-470L (ON SEMICONDUCTOR) RADIATION HARDENED HIGH EFFICIENCY, 5 AMP SWITCHING REGULATORS PDF資料下載
參數(shù)資料
| 型號(hào)： | CD54-470L |
| 廠商： | ON SEMICONDUCTOR |
| 元件分類： | 基準(zhǔn)電壓源/電流源 |
| 英文描述： | RADIATION HARDENED HIGH EFFICIENCY, 5 AMP SWITCHING REGULATORS |
| 中文描述： | 抗輻射高效，5安培開關(guān)穩(wěn)壓器 |
| 文件頁(yè)數(shù)： | 14/18頁(yè) |
| 文件大小： | 158K |
| 代理商： | CD54-470L |
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)當(dāng)前第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)
NCP1402
http://onsemi.com
14
300
200
0
400
0
125
3
2
1
I
i
,
μ
A
0
V
in
, INPUT VOLTAGE (V)
Figure 57. NCP1402SNXXT1 No Load Input
Current vs. Input Voltage
Figure 58. NCP1402SNXXT1 Maximum Output
Current vs. Input Voltage
I
O
,
150
0
1.9 V
NCP1402SNXXT1
L = 47
μ
H
I
O
= 0 mA
T
A
= 25
°
C
V
in
, INPUT VOLTAGE (V)
25
50
75
100
4
5
100
6
2.7 V
3.0 V
3.3 V
5.0 V
1.9 V
2.7 V
3.0 V
3.3 V
5.0 V
NCP1402SNXXT1
L = 47
μ
H
T
A
= 25
°
C
1
2
3
4
5
DETAILED OPERATING DESCRIPTION
Operation
The NCP1402 series are monolithic power switching
regulators optimized for applications where power drain
must be minimized. These devices operate as variable
frequency, voltage mode boost regulators and designed to
operate in continuous conduction mode. Potential
applications include low powered consumer products and
battery powered portable products.
The NCP1402 series are low noise variable frequency
voltagemode DCDC converters, and consist of softstart
circuit, feedback resistor, reference voltage, oscillator, PFM
comparator, PFM control circuit, current limit circuit and
power switch. Due to the onchip feedback resistor network,
the system designer can get the regulated output voltage
from 1.8 V to 5 V with a small number of external
components. The operating current is typically 30 A
(V
OUT
= 1.9 V), and can be further reduced to about 0.6 A
when the chip is disabled (V
CE
< 0.3 V).
The NCP1402 operation can be best understood by
examining the block diagram in Figure 2. PFM comparator
monitors the output voltage via the feedback resistor. When
the feedback voltage is higher than the reference voltage, the
power switch is turned off. As the feedback voltage is lower
than reference voltage and the power switch has been off for
at least a period of minimum offtime decided by PFM
oscillator, the power switch is then cycled on for a period of
ontime also decided by PFM oscillator, or until current
limit signal is asserted. When the power switch is on, current
ramps up in the inductor, storing energy in the magnetic
field. When the power switch is off, the energy in the
magnetic field is transferred to output filter capacitor and the
load. The output filter capacitor stores the charge while the
inductor current is high, then holds up the output voltage
until next switching cycle.
Soft Start
There is a soft start circuit in NCP1402. When power is
applied to the device, the soft start circuit pumps up the output
voltage to approximately 1.5 V at a fixed duty cycle, the level
at which the converter can operate normally. What is more,
the startup capability with heavy loads is also improved.
Regulated Converter Voltage (V
OUT
)
The V
OUT
is set by an internal feedback resistor network.
This is trimmed to a selected voltage from 1.8 to 5.0 V range
in 100 mV steps with an accuracy of
2.5%.
Current Limit
The NCP1402 series utilizes cyclebycycle current
limiting as a means of protecting the output switch
MOSFET from overstress and preventing the small value
inductor from saturation. Current limiting is implemented
by monitoring the output MOSFET current buildup during
conduction, and upon sensing an overcurrent conduction
immediately turning off the switch for the duration of the
oscillator cycle.
The voltage across the output MOSFET is monitored and
compared against a reference by the VLX limiter. When the
threshold is reached, a signal is sent to the PFM controller
block to terminate the power switch conduction. The current
limit threshold is typically set at 350 mA.
Enable / Disable Operation
The NCP1402 series offer IC shutdown mode by chip
enable pin (CE pin) to reduce current consumption. An
internal pullup resistor tied the CE pin to OUT pin by
default i.e. user can float the pin CE for permanent “On”.
When voltage at pin CE is equal or greater than 0.9 V, the
chip will be enabled, which means the regulator is in normal
operation. When voltage at pin CE is less than 0.3 V, the chip
is disabled, which means IC is shutdown.
Important: DO NOT apply a voltage between 0.3 V and 0.9 V to pin CE as this is the CE pin’s hyteresis voltage
range. Clearly defined output states can only be obtained by applying voltage out of this range.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| CD54-74AC623 | Circular Connector; No. of Contacts:55; Series:JTPQ00R; Body Material:Aluminum; Connecting Termination:Crimp; Connector Shell Size:22; Circular Contact Gender:Pin; Circular Shell Style:Wall Mount Receptacle; Insert Arrangement:22-55 |
| CD54AC623 | OCTAL-BUS TRANSCEIVER,3-STATE, NON-INVERTING |
| CD74AC623M96 | OCTAL-BUS TRANSCEIVER,3-STATE, NON-INVERTING |
| CD74AC623NSR | OCTAL-BUS TRANSCEIVER,3-STATE, NON-INVERTING |
| CD54-74AC109 | DUAL J-K FLIP-FLOP WITH SET RESET |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| CD54-470LC | 制造商:Sumida Corporation 功能描述:CD54-470LC |
| CD54-560 | 制造商:AITCOMPONENTS 制造商全稱:AIT Components Ltd. 功能描述:CD54 SMD POWER INDUCTOR |
| CD54573CS | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:全頻道頻段轉(zhuǎn)換電路 =M54573 |
| CD54-680 | 制造商:AITCOMPONENTS 制造商全稱:AIT Components Ltd. 功能描述:CD54 SMD POWER INDUCTOR |
| CD5474AC02 | 制造商:TI 制造商全稱:Texas Instruments 功能描述:Quad 2-Input NOR Gate |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。