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參數資料
| 型號： | TPS51511RHLT |
| 廠商： | TEXAS INSTRUMENTS INC |
| 元件分類： | 穩壓器 |
| 英文描述： | SWITCHING CONTROLLER, 350 kHz SWITCHING FREQ-MAX, PQCC20 |
| 封裝： | ROHS COMPLIANT, PLASTIC, QFN-20 |
| 文件頁數： | 4/29頁 |
| 文件大小： | 1019K |
| 代理商： | TPS51511RHLT |
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DESCRIPTION
VOSW Switcher, Dual PWM Operation Modes
SLVS735A – FEBRUARY 2007 – REVISED APRIL 2007
TPS51511 is an integrated power-management solution that combines a synchronous buck controller and a
high-current, source-only, low-dropout linear regulator (LDO) in a small 20-pin QFN package. Each output
provides voltages required by typical graphic-system applications. The switching-mode power supply portion
employs external N-channel MOSFETs to provide high current for a GPU core. The output voltage is adjustable
from 0.75 to 3.3 V with an external divider. The input voltage range of the switcher is 3 V to 28 V. The switcher
uses adaptive on-time PWM under heavy load conditions, and automatically reduces the frequency under light
loads to achieve excellent efficiency down to several mA. The output of the switcher is sensed by the VOSW pin
to generate the on-time pulse, with the voltage of VIN sensed by LL pin. The current sensing uses either the
RDS(ON) of the external rectifying MOSFET for a low-cost, lossless solution, or a sense resistor placed in series to
the rectifying MOSFET for applications needing a more accurate current limit.
The LDO can source up to 2 A DC current with only 20
F (two 10 F in parallel) ceramic output capacitors.
The main control loop of the switcher is designed as an adaptive on-time pulse width modulation (PWM)
controller. It supports two control schemes; a current mode and a proprietary D-CAP mode. D-CAP mode does
not require an external compensation circuit, and is suitable for low external component count configurations
using output capacitor(s) with an appropriate ESR value. Current-mode control has more flexibility, using an
external compensation network, and can be used to achieve stable operation with very low-ESR capacitors such
as ceramic capacitors.
These control modes are selected by the COMP terminal connection. If the COMP pin is connected to V5IN, the
TPS51511 is in D-CAP Mode. If the COMP pin is connected to the RC compensation network, the device
operates in current mode.
At the beginning of each cycle, the synchronous top MOSFET is turned on (ON state). This MOSFET is turned
off (OFF state) after the internal one-shot timer expires. The on-time issued by this one-shot is proportional to
the ratio of VOUT to VIN. In this way, the switching frequency can be kept reasonably constant over the
input-voltage range, hence it is called adaptive on-time control (see PWM frequency and Adaptive On-time
Control). The MOSFET is turned on again when the feedback information indicates insufficient output voltage
and the inductor current is below the overcurrent limit. By repeating operation in this manner, the controller
regulates the output voltage. The synchronous bottom, or the rectifying MOSFET, is turned on during each OFF
state to minimize conduction loss. The rectifying MOSFET is turned off when the inductor current indicates zero
voltage level. This enables seamless transition to the reduced frequency operation under light load conditions so
that the high efficiency is maintained over the broad range of load currents.
In the current-mode control scheme, the transconductance amplifier generates a target current level
corresponding to the voltage difference between the feedback point and the internal 750-mV reference. During
the OFF state, the PWM comparator monitors the inductor-current signal as well as the target current level, and
when the inductor-current signal goes lower than the target current level, the comparator asserts the SET signal,
switching the system to the ON state. The voltage-feedback gain is adjustable outside the controller IC to
support various types of output MOSFETs and capacitors. In the D-CAP Mode, the transconductance amplifier is
disabled and the PWM comparator directly compares the feedback-point voltage to the internal 750-mV
reference during the OFF state. When the feedback point becomes lower than the reference voltage, the
comparator asserts the SET signal, triggering the ON state.
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相關代理商/技術參數 |
參數描述 |
|---|---|
| TPS51511RHLTG4 | 功能描述:DC/DC 開關控制器 Synch Switcher Cntrlr RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數量:1 最大工作溫度:+ 125 C 安裝風格: 封裝 / 箱體:CPAK |
| TPS51513 | 制造商:TI 制造商全稱:Texas Instruments 功能描述:SINGLE PHASE D-CAP+ SYNCHRONOUS BUCK CONTROLLER WITH INTEGRATED DRIVERS FOR GENERAL IC VCORE APPLICATIONS |
| TPS51513EVM-549 | 功能描述:電源管理IC開發工具 TPS51513EVM-549 Eval Mod RoHS:否 制造商:Maxim Integrated 產品:Evaluation Kits 類型:Battery Management 工具用于評估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V |
| TPS51513EVM-549 | 制造商:Texas Instruments 功能描述:DEVELOPMENT TOOL |
| TPS51513RHB | 制造商:TI 制造商全稱:Texas Instruments 功能描述:SINGLE PHASE D-CAP+ SYNCHRONOUS BUCK CONTROLLER WITH INTEGRATED DRIVERS FOR GENERAL IC VCORE APPLICATIONS |
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