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参数资料
| 型号： | LTC3553EUD#PBF |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 电源管理 |
| 英文描述： | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC20 |
| 封装： | 3 X 3 MM, 0.75 MM HEIGHT, LEAD FREE, PLASTIC, QFN-20 |
| 文件页数： | 18/36页 |
| 文件大小： | 518K |
| 代理商： | LTC3553EUD#PBF |
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LTC3553
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after entering the PDN1 state the pushbutton circuitry will
transition into the hard reset (HR) state.
In the HR state, all supplies are disabled. The PowerPath
circuitry is placed in an ultralow quiescent state to minimize
battery drain. If no external charging supply is present
(VBUS) then the ideal diode is shut down, disconnecting
VOUT from BAT to further minimize battery drain. The ultra-
low power consumption in the HR state makes it ideal for
shipping or long term storage, minimizing battery drain.
The following events cause the state machine to transition
out of HR into the power-up (PUP1) state:
ON input low for 400ms (PB400MS)
Application of external power (EXTPWR)
Upon entering the PUP1 state, the pushbutton circuitry will
sequence up the buck and LDO regulators. The state of the
SEQ pin determines which regulator is enabled before the
other. If SEQ is low, the buck regulator is enabled rst. If
SEQ is high, the LDO regulator is enabled rst. The second
regulator is enabled once the feedback voltage of the rst
regulator nears regulation. The SEQ pin must be tied to
either VOUT or ground.
The BUCK_ON and LDO_ON inputs are ignored in the PUP1
state. The state machine remains in the PUP1 state for
ve seconds. During the ve seconds, the application’s
microprocessor, powered by the regulators, has time to
boot and assert BUCK_ON and/or LDO_ON. Five seconds
after entering the PUP1 state, the pushbutton circuitry
automatically transitions into the power-on (PON) state.
In the PON state, the regulators can be enabled and shut
down at any time by the BUCK_ON and LDO_ON pins. A
high on BUCK_ON is needed to keep the buck enabled, and
a high on LDO_ON is needed to keep the LDO enabled. To
remain in the PON state, the application circuit must keep
at least one of the BUCK_ON or LDO_ON inputs high, else
the state machine enters the power-down (PDN2) state.
When BUCK_ON and LDO_ON are both low, or when
VOUT drops to its undervoltage lockout (VOUT UVLO)
threshold, the state machine will leave the PON state and
enter the power-down (PDN2) state. In the power-down
state (PDN2), both regulators are kept disabled regard-
less of the states of the BUCK_ON and LDO_ON pins.
The state machine remains in the power-down state for
one second, before automatically entering the power-off
(POFF) state. This one second delay allows all LTC3553
generated supplies time to power down completely before
they can be re-enabled.
The same events used to exit the hard reset (HR) state
are also used to exit the POFF state and enter the PUP2
state. The PUP2 state operates in the same manner as
the PUP1 state previously described.
Both regulators remain powered up during the ve second
power-up (PUP1 or PUP2) period, regardless of the state
of the BUCK_ON and LDO_ON inputs.
In either the HR or POFF states, if either the BUCK_ON
or LDO_ON pin is driven high, the pushbutton circuitry
directly enters the PON state, without passing through
the power-up (PUP1 or PUP2) states. This is because by
asserting logic high on the BUCK_ON or LDO_ON pins,
the application has already told the LTC3553 exactly which
regulator(s) to turn on, so there is no need for an inter-
mediate PUP state in which both regulators are enabled
for ve seconds.
Starting from the HR state, bringing the BUCK_ON and/or
LDO_ON pin(s) high enables the PowerPath, if it wasn’t
already enabled due to VBUS power being available. This
powers up the VOUT pin from VBUS or BAT. When the VOUT
voltage rises above the VOUT UVLO threshold, the state
machine transitions from the HR state into the PON state,
allowing the selected regulator(s) to turn on.
The hard reset (HRST) event is generated by pressing and
holding the pushbutton (ON input low) for ve seconds.
For a valid HRST event to occur the button press must
start in the PUP1, PUP2 or PON state, but can end in any
state. If a valid HRST event is present in PON, PDN2 or
POFF, then the state machine will transition to the PDN1
state and subsequently transition to the HR state one
second later.
Debounced Pushbutton Output (PBSTAT)
In the PON, PUP1, and PUP2 states, the PBSTAT open-
drain output pin outputs a debounced version of the ON
pushbutton signal. ON must be held low for at least 50ms
for the pushbutton interface to recognize it and cause
OPERATION
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相关代理商/技术参数 |
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| LTC3554 | 制造商:LINER 制造商全称:Linear Technology 功能描述:Micropower USB Power Manager with Li-Ion Charger and Two Step-Down Regulators |
| LTC3554EPD | 制造商:LINER 制造商全称:Linear Technology 功能描述:Micropower USB Power Manager with Li-Ion Charger and Two Step-Down Regulators |
| LTC3554EPD#PBF | 功能描述:IC USB POWER MANAGER 20-UTQFN RoHS:是 类别:集成电路 (IC) >> PMIC - 电源管理 - 专用 系列:- 标准包装:1 系列:- 应用:手持/移动设备 电流 - 电源:- 电源电压:3 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:14-WFDFN 裸露焊盘 供应商设备封装:14-LLP-EP（4x4） 包装:Digi-Reel® 配用:LP3905SD-30EV-ND - BOARD EVALUATION LP3905SD-30 其它名称:LP3905SD-30DKR |
| LTC3554EPD#TRPBF | 功能描述:IC USB POWER MANAGER 20-UTQFN RoHS:是 类别:集成电路 (IC) >> PMIC - 电源管理 - 专用 系列:- 应用说明:Ultrasound Imaging Systems Application Note 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:37 系列:- 应用:医疗用超声波成像，声纳 电流 - 电源:- 电源电压:2.37 V ~ 6 V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:56-WFQFN 裸露焊盘 供应商设备封装:56-TQFN-EP（8x8） 包装:管件 |
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