- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄385855 > sp6650 High Efficiency 600mA Synchronous Buck Regulator(高效率,600mA同步補償穩(wěn)壓器) PDF資料下載
參數(shù)資料
| 型號： | sp6650 |
| 英文描述： | High Efficiency 600mA Synchronous Buck Regulator(高效率,600mA同步補償穩(wěn)壓器) |
| 中文描述： | 600mA的高效率同步降壓穩(wěn)壓器（高效率，600mA的同步補償穩(wěn)壓器） |
| 文件頁數(shù)： | 5/17頁 |
| 文件大?。?/td> | 170K |
| 代理商： | SP6650 |
5
Rev. 2/4/02
SP6650 High Efficiency 600mA Synchronous Buck Regulator
Copyright 2002 Sipex Corporation
OPERATION
The SP6650 is a synchronous buck regulator
with an input voltage range of +2.7V to +6.5V
and an output that is either preset to +3.3V, or
adjustable between +1.25V and V
IN
. The SP6650
features a unique on-time control loop that runs
in discontinuous conduction mode (DCM) or
continuous conduction mode (CCM) using syn-
chronous rectification. Other features include
overtemperature shutdown, overcurrent protec-
tion, undervoltage lockout, digitally controlled
enable, a battery low indicator, and an external
feedback pin.
The SP6650 operates with a light load quiescent
current of 70
μ
A using a 0.4
PMOS main
switch and a 0.3
NMOS auxiliary switch. It
operates with excellent efficiency across the
entire load range, making it an ideal solution for
battery powered applications and low current
step-down conversions. The part smoothly tran-
sitions into a 100% duty cycle under heavy load/
low input voltage conditions.
On-Time Control
The SP6650 uses a precision comparator and a
minimum on-time one-shot to regulate the out-
put voltage and control the inductor current
under normal load conditions. As the feedback
node (negative terminal of the loop comparator)
drops below the reference, the loop comparator
output goes high and closes the main switch.
The minimum on-time one shot is triggered,
setting a logic high for the duration defined by:
T
ON
=
K
ON
V
IN
-V
OUT
where:
K
ON
= 2.7
μ
s*V constant
V
IN
= V
IN
pin voltage
V
OUT
= V
OUT
pin voltage
The outputs of the loop comparator and the on-
time one shot are OR'd together, inverted, and
buffered to drive the gate of the high side PMOS
main switch. Increasing inductor current causes
the output to increase through the ESR (equiva-
lent series resistance) of the output capacitor. As
V
OUT
rises above the regulation threshold, the
loop comparator output resets low. Termination
of the on cycle occurs when both the loop
comparator and the on-time one shot goes to
logic low, or the inductor current limit has been
reached.
The discharge phase follows with the high side
PMOS switch opening and the low side NMOS
switch closing to provide a discharge path for
the inductor current. The decreasing inductor
current and the load current cause the output
voltage to droop. Under normal load conditions
when the inductor current is below the pro-
grammed limit, the off-time will continue until
the output voltage falls below the regulation
threshold, which initiates a new charge cycle via
the loop comparator.
The inductor current "floats" in continuous con-
duction mode. During this mode the inductor
peak current is below the programmed limit and
the valley current is above zero. This is to satisfy
load currents that are greater than half the mini-
mum current ripple. The current ripple, I
LR
, is
defined by the equation:
I
LR
≈
K
ON
* V
IN
-V
OUT
-I
OUT
*Rch
L
V
IN
-V
OUT
where:
L
I
OUT
= Load current
Rch
= PMOS on resistance, 0.4
typ.
If the I
OUT
*Rch term is negligible compared
with (V
IN
-V
OUT
), the above equation simplifies
to:
I
LR
≈
K
ON
L
= Inductor value
For most applications, the inductor current ripple
controlled by the SP6650 is constant regardless
of input and output voltage. Because the output
voltage ripple is equal to:
V
OUT
(ripple) = I
LR
*R
ESR
where:
R
ESR
= ESR of the output capacitor
the output ripple of the SP6650 regulator is
independent of the input and output voltages.
For battery powered applications, where the
battery voltage changes significantly, the SP6650
provides constant output voltage ripple through-
out the battery lifetime. This greatly simplifies
the LC filter design.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| SP682 | Ultra-Low Power Inverting Voltage Doubler(極低功耗，反相電壓倍增器) |
| SP702 | SILICON GATE ENHANCEMENT MODE RF POWER VDMOS TRANSISTOR |
| SP741 | SILICON GATE ENHANCEMENT MODE RF POWER VDMOS TRANSISTOR |
| SP8024 | 200V/us Integrated APC Amplifier with Gain Adjust & Differential Output |
| SP8025 | 200V/us Integrated APC Amplifier with Gain Adjust & Differential Output |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| SP6650EB | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Evaluation Board Manual |
| SP6650EU | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Evaluation Board Manual |
| SP6650EU/TR | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:High Efficiency 600mA Synchronous Buck Regulator Ideal for portable designs powered with Li Ion battery |
| SP6650EU-L | 功能描述:DC/DC 開關(guān)控制器 High Eff 600mA Synchronous RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK |
| SP6650EU-L/TR | 功能描述:DC/DC 開關(guān)控制器 High Eff 600mA Synchronous RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。