- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄375724 > FAN5307SX (FAIRCHILD SEMICONDUCTOR CORP) High-Efficiency Step-Down DC-DC Converter PDF資料下載
參數(shù)資料
| 型號： | FAN5307SX |
| 廠商： | FAIRCHILD SEMICONDUCTOR CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | High-Efficiency Step-Down DC-DC Converter |
| 中文描述： | 0.7 A SWITCHING REGULATOR, 1200 kHz SWITCHING FREQ-MAX, PDSO5 |
| 封裝： | ROHS COMPLIANT, MO-178AA, SOT-23, 5 PIN |
| 文件頁數(shù)： | 7/12頁 |
| 文件大小： | 633K |
| 代理商： | FAN5307SX |
PRODUCT SPECIFICATION
FAN5307
7
REV. 1.0.2 6/22/04
Detailed Operation Description
The FAN5307 is a step-down converter operating in a
current-mode PFM/PWM architecture with a typical switch-
ing frequency of 1MHz. At moderate to heavy loads, the con-
verter operates in pulse-width-modulation (PWM) mode. At
light loads the converter enters a power-save mode (PFM
pulse skipping) to keep the efficiency high.
PWM Mode
In PWM mode, the device operates at a fixed frequency of
1MHz. At the beginning of each clock cycle, the P-channel
transistor is turned on. The inductor current ramps up and is
monitored via an internal circuit. The P-channel switch is
turned off when the sensed current causes the PWM compar-
ator to trip when the output voltage is in regulation or when
the inductor current reaches the current limit (set internally
to typically 520mA). After a minimum dead time the N-
channel transistor is turned on and the inductor current ramps
down. As the clock cycle is completed, the N-channel switch
is turned off and the next clock cycle starts.
PFM (Power Save) Mode
As the load current decreases and the peak inductor current
no longer reaches the typical threshold of 80mA, the con-
verter enters pulse-frequency-modulation (PFM) mode. In
PFM mode the device operates with a variable frequency and
constant peak current thus reducing the quiescent current to
minimum. Consequently, the high efficiency is maintained at
light loads. As soon as the output voltage falls below a
threshold, set at 0.8% above the nominal value, the P-chan-
nel transistor is turned on and the inductor current ramps up.
The P-channel switch turns off and the N-channel turns on
as the peak inductor current is reached (typical 140mA).
The N-channel transistor is turned off before the inductor
current becomes negative. At this time the P-channel is
switched on again starting the next pulse. The converter
continues these pulses until the high threshold (typical 1.6%
above nominal value) is reached. A higher output voltage in
Block Diagram
FB
ERROR
AMPLIFIER
VOLTAGE
COMPARATOR
REF
FB
REF
IS
IS
CURRENT
SENSE
NEG. LIMIT
SENSE
DIGITAL
SOFT START
UNDER VOLTAGE
LOCKOUT
LOGIC
CONTROL
MOSFET
DRIVER
OSC
SLOPE COMPENSATION
PFM
COMPARATOR
COMPARATOR
OVER
NEG. LIMIT
COMPARATOR
IS
GND
LX
VIN
EN
GND
0.5V
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| FAN5307 | High-Efficiency Step-Down DC-DC Converter |
| FAN5307MP18X | High-Efficiency Step-Down DC-DC Converter |
| FAN5308 | 800mA High-Efficiency Step-Down DC-DC Converter |
| FAN5308MPX | 800mA High-Efficiency Step-Down DC-DC Converter |
| FAN53168 | 6-Bit VID Controlled 2-4 Phase DC-DC Controller |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| FAN5308 | 制造商:FAIRCHILD 制造商全稱:Fairchild Semiconductor 功能描述:800mA High-Efficiency Step-Down DC-DC Converter |
| FAN5308_07 | 制造商:FAIRCHILD 制造商全稱:Fairchild Semiconductor 功能描述:800mA High-Efficiency Step-Down DC-DC Converter |
| FAN5308MPX | 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 SYSTEM_POWER 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 |
| FAN5308MPX | 制造商:Fairchild Semiconductor Corporation 功能描述:IC DC/DC CONVERTER ((NW)) 制造商:Fairchild Semiconductor Corporation 功能描述:IC, STEP-DOWN DC/DC CONVERTER, MLP-6 |
| FAN5309M_ABB3086B WAF | 制造商:Fairchild Semiconductor Corporation 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復。