參數(shù)資料
型號: PM6670ATR
廠商: STMICROELECTRONICS
元件分類: 穩(wěn)壓器
英文描述: 1.4 A SWITCHING CONTROLLER, QCC24
封裝: 4 X 4 MM, LEAD FREE, VFQFN-24
文件頁數(shù): 30/55頁
文件大?。?/td> 849K
代理商: PM6670ATR
Device description
PM6670
36/53
7.2
VTTREF buffered reference and VTT LDO section
The PM6670 provides the required DDR2/3 reference voltage on the VTTREF pin. The
internal buffer tracks half the voltage on the VSNS pin and has a sink and source capability
up to 15mA.
Higher currents rapidly deteriorate the output accuracy. A 10nF to 100nF (33nF typ.) bypass
capacitor to SGND is required for stability.
The VTT Low-Drop-Out linear regulator has been designed to sink and source up to 2A
peak current and 1A continuously. The VTT voltage tracks VTTREF within ±35mV.
A remote voltage sensing pin (VTTSNS) is provided to recovery voltage drops due to
parasitic resistance. In DDR2/3 applications, the linear regulator input LDOIN is typically
connected to VDDQ output; connecting LDOIN pin to a lower voltage, if available in the
system, reduces the power dissipation of the LDO.
A minimum output capacitance of 20
F (2x10F MLCC capacitors) is enough to assure
stability and fast load transient response.
7.2.1
VTT and VTTREF Soft-Start
Soft-Start on VTT and VTTREF outputs is achieved by current clamping.
The LDO linear regulator is provided with a current foldback protection: when the output
voltage exits the internal ±10% VTT-Good window, the output current is clamped at ±1A. Re-
entering VTT-Good window releases the current limit clamping.
The foldback mechanism naturally implements a two steps soft-start charging the output
capacitors with a 1A constant current.
Something similar occurs at VTTREF pin, where the output capacitor is smoothly charged at
a fixed 40mA current limit.
7.2.2
VTTREF and VTT outputs discharge
The Tracking Discharge mechanism involves the VTT linear regulator. When the Suspend-
To-Disk state is entered, the switching regulator is turned OFF.
At the same time the LDO drains a 1A constant current from LDOIN and keeps VTT in track
with VTTREF that, in turn, is half the voltage at the VSNS pin. When the VDDQ output
reaches 400mV, the PM6670 switches on the internal discharge MOSFETs to complete the
In Soft Discharge (i.e. Non-Tracking Discharge) the PM6670 disables the internal regulators
and suddenly turns on the discharge MOSFETs on each output.
相關(guān)PDF資料
PDF描述
PM6670 1.4 A SWITCHING CONTROLLER, QCC24
PM6675ASTR 3 A SWITCHING CONTROLLER, QCC24
PM6675AS 3 A SWITCHING CONTROLLER, QCC24
PM6675ATR SWITCHING CONTROLLER, QCC24
PM6675TR SWITCHING CONTROLLER, QCC24
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PM6670STR 功能描述:DC/DC 開關(guān)控制器 Complete DDR2/3 Mem Pwr supply controllr RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
PM6670TR 功能描述:直流/直流開關(guān)調(diào)節(jié)器 Complete DDR2/3 Mem Pwr supply controllr RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5
PM6675 制造商:STMicroelectronics 功能描述: 制造商:STMicroelectronics 功能描述:LDO CNTRLR STDN 0.6V TO 3.3V/1.5V 24PIN VFQFPN - Rail/Tube
PM6675AS 功能描述:DC/DC 開關(guān)控制器 DDR 2/3 Memory Pwr Cntrl RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK