参数资料
| 型号： | SP6650EU-L |
| 厂商： | Exar Corporation |
| 文件页数： | 8/17页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC 3.3V/ADJ 10MSOP |
| 标准包装： | 50 |
| 类型： | 降压（降压） |
| 输出类型： | 两者兼有 |
| 输出数： | 1 |
| 输出电压： | 3.3V，1.25 V ~ 5 V |
| 输入电压： | 2.7 V ~ 6.5 V |
| 电流 - 输出： | 600mA |
| 同步整流器： | 是 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 10-TFSOP，10-MSOP（0.118"，3.00mm 宽） |
| 包装： | 管件 |
| 供应商设备封装： | 10-MSOP |
| 其它名称： | 1016-1215-5 |
S P 6 6 5 0
H i g h E f f i c i e n c y 6 0 0 m A S y n c h r o n o u s B u c k R e g u l a t o r
THEORY OF 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 VIN. The
SP6650 features a unique on-time control loop
that runs in discontinuous conduction mode
(DCM) or continuous conduction mode (CCM)
using synchronous rectification. Other features
include overtemperature shutdown,
overcurrent protection, undervoltage lockout,
digitally controlled enable, a battery low
indicator, and an external feedback pin.
The SP6650 operates with a light load
quiescent current of 70μA using a 0.4Ω PMOS
main switch and a 0.3Ω 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 transitions into a 100% duty
cycle under heavy load/low input voltage
conditions.
O N -T IME C ONTROL
The SP6650 uses a precision comparator and a
minimum on-time one-shot to regulate the
output 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:
where:
K ON = 2.7μs*V constant
V IN = V IN pin voltage
V OUT = V OUT pin voltage
The outputs of the loop comparator and the
ontime 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
(equivalent 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 programmed 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
conduction 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 minimum current
ripple. The current ripple, I LR , is defined by the
equation:
where:
L = Inductor value
I OUT = Load current
Rch = PMOS on resistance, 0.4Ω typ.
If the I OUT *Rch term is negligible compared
with (V IN -V OUT ), the above equation simplifies
to:
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:
where:
? 2012 Exar Corporation
8/17
Rev. 2.0.0
相关PDF资料 |
PDF描述 |
|---|---|
| SP6651AEU-L | IC REG BUCK SYNC ADJ 0.8A 10MSOP |
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相关代理商/技术参数 |
参数描述 |
|---|---|
| SP6650EU-L/TR | 功能描述:DC/DC 开关控制器 High Eff 600mA Synchronous RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| SP6650UEB | 功能描述:电源管理IC开发工具 Hi Efficiency 600mA Sync Buck Regulator RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
| SP6651A | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:High Efficiency 800mA Synchronous Buck Regulator Ideal for portable designs powered with Li Ion battery |
| SP6651AEB | 功能描述:DC/DC 开关控制器 Hi Efficiency 800mA Sync Buck Regulator RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| SP6651AER | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:High Efficiency 800mA Synchronous Buck Regulator Ideal for portable designs powered with Li Ion battery |
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