参数资料
| 型号： | SP6644EU-L/TR |
| 厂商： | Exar Corporation |
| 文件页数： | 8/15页 |
| 文件大小： | 0K |
| 描述： | IC REG BOOST SYNC 3.3V/ADJ 8MSOP |
| 标准包装： | 2,500 |
| 类型： | 升压（升压） |
| 输出类型： | 两者兼有 |
| 输出数： | 1 |
| 输出电压： | 3.3V，2 V ~ 5.5 V |
| 输入电压： | 0.9 V ~ 3.3 V |
| 电流 - 输出： | 175mA |
| 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： | 8-TSSOP，8-MSOP（0.118"，3.00mm 宽） |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 8-MSOP |
I PEAK = 1400
DESCRIPTION
The SP6644/6645 devices are high-efficiency,
low-power step-up DC-DC converters ideal for
single or dual alkaline cell applications such as
pagers, remote controls, and other low-power
portable end products.
The SP6644/6645 devices feature a 5nA logic-
controlled shutdown mode and a dedicated
low-battery detector circuitry. Both devices
contain a 0.8 ? synchronous rectifier, a 0.5 ?
N-channel MOSFET power switch, an internal
voltage reference, circuitry for pulse-frequency-
modulation, and an under voltage comparator.
The output voltage for the SP6644/6645 devices
can be adjusted from +2V to +5.5V by
manipulating two external resistors. The output
voltage is preset to +3.3V.
THEORY OF OPERATION
The SP6644/6645 devices are ideal for end
products that function with a single or dual alkaline
cell, such as remote controls, pagers, and other
portable consumer products. Designers can
implement the SP6644/6645 devices into
applications with the following power
management operating states: 1. where the
primary battery is good and the load is active, and
2. where the primary battery is good and
the load is sleeping.
peak inductor current is satisfied. This is indicated
by the falling edge of the I-Charge comparator
output. The approximate inductor charging time
is defined by:
t CHARGE ? L x I PEAK / V BATT
where t CHARGE [s] is the approximate inductor
charging time, L [H] is the inductance, I PEAK [A]
is the peak inductor current, and V BATT [V] is the
input voltage to the device.
The peak inductor current, I PEAK , is programmed
externally by putting a resistor between the R LIM
pin and ground. This is defined by:
R LIM
where I PEAK [A] is the peak inductor current and
R LIM [ ? ] is the value of the resistor connected
from pin R LIM to ground.
When the charging N MOSFET turns off, the
discharging P MOSFET turns on and the inductor
current flows into the output capacitor and the
load recharging the output. When the current
through the discharging P MOSFET approaches
zero, the I-Discharge comparator indicates to the
logic to turn off the P MOSFET. The approximate
time for discharging the inductor current can be
determined by:
In the first operating state where the primary
supply is good and the load is active, the
SP6644/6645 devices typically offer 88%
t DCHG ?
L x I PEAK
V OUT - V BATT
efficiency, drawing tens of milliamps.
Applications will predominantly operate in the
second state where the primary supply is good
and the load is sleeping. The SP6644/6645 devices
draw a very low quiescent current while the load
in its disabled state will draw typically hundreds
of microamps.
The pulse-frequency-modulation (PFM) circuitry
provides higher efficiencies at low to moderate
output loads than traditional PWM converters are
capable of delivering.
where t DCHG [s] is the time to discharge the
inductor, L [H] is the inductance, I PEAK [A] is the
peak inductor current, V OUT [V] is the output
voltage, and V BATT [V] is the input voltage to the
device.
The output filter capacitor stores charge while
current from the inductor is high and holds the
output voltage high until the discharge phase of
the next switching cycle, smoothing power flow
to the load. Between switching cycles, the
inductor damping switch is closed suppressing
the ringing caused by the inductor and the parasitic
capacitance on the LX node.
In a state where the error comparator detects that
the output voltage at V OUT is too low, the internal
N-channel MOSFET switch is turned on until the
Date: 11/30/04
SP6644/6645 High Efficiency Boost Regulator
8
? Copyright 2004 Sipex Corporation
相关PDF资料 |
PDF描述 |
|---|---|
| SP6648EU-L/TR | IC REG BOOST SYNC 0.4A 10MSOP |
| SP6650EU-L | IC REG BUCK SYNC 3.3V/ADJ 10MSOP |
| SP6651AEU-L | IC REG BUCK SYNC ADJ 0.8A 10MSOP |
| SP6652EU-L | IC REG BUCK SYNC ADJ 1A 10MSOP |
| SP6654EU-L | IC REG BUCK SYNC ADJ 0.8A 10MSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| SP6644TR | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Single/Dual Alkaline Cell, High Efficiency Boost DC-DC Regulator |
| SP6644UEB | 功能描述:电源管理IC开发工具 Hi-Efficiency Boost DC/DC 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 |
| SP6645 | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Evaluation Board Manual |
| SP6645EU | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Single/Dual Alkaline Cell, High Efficiency Step-Up DC-DC Converter |
| SP6645EU-L | 功能描述:开关变换器、稳压器与控制器 Sngl/Dual Alkaline Cell High Eff DC-DC RoHS:否 制造商:Texas Instruments 输出电压:1.2 V to 10 V 输出电流:300 mA 输出功率: 输入电压:3 V to 17 V 开关频率:1 MHz 工作温度范围: 安装风格:SMD/SMT 封装 / 箱体:WSON-8 封装:Reel |
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