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参数资料
| 型号： | LTC3240EDC-2.5#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 7/12页 |
| 文件大小： | 0K |
| 描述： | IC REG MULTI CONFIG 2.5V 6DFN |
| 标准包装： | 2,500 |
| 类型： | 降压（降压），升压（升压），切换电容（充电泵） |
| 输出类型： | 固定 |
| 输出数： | 1 |
| 输出电压： | 2.5V |
| 输入电压： | 1.8 V ~ 5.5 V |
| PWM 型： | Burst Mode? |
| 频率 - 开关： | 1.2MHz |
| 电流 - 输出： | 150mA |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 6-WFDFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 6-DFN-EP（2x2） |
LTC3240-3.3/LTC3240-2.5
OPERATIO
(Refer to the Block Diagram)
The LTC3240 is a step-up/step-down charge pump DC/DC
converter. For V IN greater than V OUT by about 100mV it
operates as a low dropout regulator. Once V IN drops to
within 100mV of V OUT , the part automatically switches
into charge pump mode to boost V IN to the regulated
output voltage. Regulation is achieved by sensing the
output voltage through an internal resistor divider and
modulating the charge pump output current based on
the error signal.
In the charge pump mode a 2-phase nonoverlapping clock
activates the charge pump switches. The ?ying capacitor
is charged from V IN on the ?rst phase of the clock. On
the second phase of the clock it is stacked in series with
V IN and connected to V OUT . This sequence of charging
and discharging the ?ying capacitor continues at a free
running frequency of 1.2MHz (typ).
Shutdown Mode
In shutdown mode, all circuitry is turned off and the
LTC3240 draws only leakage current from the V IN supply.
Furthermore, V OUT is disconnected from V IN . The ? S ? H ? D ? N
pin is a CMOS input with a threshold voltage of approxi-
mately 0.8V. The LTC3240 is in shutdown when a logic
low is applied to the ? S ? H ? D ? N pin. Since the ? S ? H ? D ? N pin is a
high impedance CMOS input, it should never be allowed
to ?oat. To ensure that its state is de?ned, it must always
be driven with a valid logic level.
Since the output voltage of this device can go above the
input voltage, circuitry is required to control the state of
the converter even in shutdown. This circuitry will draw
an input current of 5 μ A in shutdown. However, this cur-
rent is eliminated when the output voltage (V OUT ) drops
to less than approximately 0.8V.
Burst Mode Operation
The LTC3240 provides automatic Burst Mode operation
while operating as a charge pump, to increase ef?ciency of
is initiated if the output load current falls below an inter-
nally programmed threshold. Once Burst Mode operation
is initiated, the part shuts down the internal oscillator to
reduce the switching losses, and goes into a low current
state. This state is referred to as the sleep state in which
the IC consumes only about 65 μ A from the input. When
the output voltage droops enough to overcome the burst
comparator hysteresis, the part wakes up and commences
normal ?xed frequency operation recharging the output
capacitor. If the output load is still less than the Burst Mode
threshold the part will re-enter sleep state. This Burst Mode
threshold varies with V IN , V OUT and the choice of output
storage capacitor.
Soft-Start
The LTC3240 has built-in soft-start circuitry to prevent
excessive current ?ow during start-up. The soft-start is
achieved by internal circuitry that slowly ramps the amount
of current available to the output storage capacitor from
zero to a value of 300mA over a period of approximately
2ms. The soft-start circuitry is reset in the event of a com-
manded shutdown or thermal shutdown.
Short-Circuit/Thermal Protection
The LTC3240 has built-in short-circuit current limit as
well as overtemperature protection. During a short-circuit
condition, the part automatically limits its output current to
approximately 300mA. If the junction temperature exceeds
approximately 160°C the thermal shutdown circuitry shuts
down current delivery to the output. Once the junction
temperature drops back to approximately 150°C cur-
rent delivery to the output is resumed. The LTC3240 will
cycle in and out of thermal shutdown inde?nitely without
latch-up or damage until the short-circuit condition on
V OUT is removed. Long term overstress (i.e. operation at
junction temperatures above 125°C) should be avoided
as it reduces the lifetime of the part and can result in
degraded performance.
the power converter at light loads. Burst Mode operation
3240fb
7
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相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3240EDC-3.3 | 制造商:LINER 制造商全称:Linear Technology 功能描述:3.3V/2.5V Step-Up/ Step-Down Charge Pump DC/DC Converter |
| LTC3240EDC3.3#PBF | 制造商:Linear Technology 功能描述:Charge Pump STPUP/STPDN 3.3V 150mA 6-Pin DFN EP |
| LTC3240EDC-3.3#PBF | 制造商:Linear Technology 功能描述:DC-DC CONVERTER BUCK 1.22MHZ 制造商:Linear Technology 功能描述:DC-DC CONVERTER, BUCK, 1.22MHZ, 3.3V, 150mA, DFN-6; Primary Input Voltage:5.5V; No. of Outputs:1; Output Voltage:3.3V; Output Current:150mA; No. of Pins:6; Operating Temperature Min:-40C; Operating Temperature Max:85C ;RoHS Compliant: Yes |
| LTC3240EDC-3.3#TRMPBF | 功能描述:IC REG MULTI CONFIG 3.3V 6DFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 产品培训模块:High Efficiency Current Mode Switching Regulators CMOS LDO Regulators 特色产品:BD91x Series Step-Down Regulators 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:两者兼有 输出数:2 输出电压:3.3V，0.8 V ~ 2.5 V 输入电压:4.5 V ~ 5.5 V PWM 型:电流模式 频率 - 开关:1MHz 电流 - 输出:1.5A 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:20-VFQFN 裸露焊盘 包装:带卷 (TR) 供应商设备封装:VQFN020V4040 产品目录页面:1373 (CN2011-ZH PDF) 其它名称:BD9152MUV-E2TR |
| LTC3240EDC-3.3#TRPBF | 功能描述:IC REG MULTI CONFIG 3.3V 6DFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:升压（升压） 输出类型:可调式 输出数:1 输出电压:1.24 V ~ 30 V 输入电压:1.5 V ~ 12 V PWM 型:电流模式，混合 频率 - 开关:600kHz 电流 - 输出:500mA 同步整流器:无 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) 供应商设备封装:8-SOIC |
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