- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄374732 > SC486IMLTRT (Semtech Corporation) Complete DDR1/2/3 Memory Power Supply PDF資料下載
參數(shù)資料
| 型號： | SC486IMLTRT |
| 廠商： | Semtech Corporation |
| 英文描述： | Complete DDR1/2/3 Memory Power Supply |
| 中文描述： | 完全DDR1/2/3內(nèi)存供電 |
| 文件頁數(shù)： | 18/26頁 |
| 文件大?。?/td> | 382K |
| 代理商： | SC486IMLTRT |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁當(dāng)前第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁
18
2006 Semtech Corp.
www.semtech.com
SC486
POWER MANAGEMENT
Thermal Considerations
The junction temperature of the device may be calculated
as follows:
C
P
T
T
JA
D
A
J
°
θ
+
=
Where:
T
A
= ambient temperature (°C)
P
D
= power dissipation in (W)
θ
= thermal impedance junction to ambient from
absolute maximum ratings (°C/W)
The power dissipation may be calculated as follows,
assuming that VTT spends 50% of its time sourcing
current and 50% sinking:
(
)
W
ITT
VTT
VTTIN
D
mA
1
VBST
f
Q
V
I
VDDP
I
VCCA
P
+
g
g
VDDP
VCCA
D
+
+
+
=
Where:
VCCA = chip supply voltage (V)
I
= operating current (A)
VDDP = gate drive supply voltage (V)
I
VDDP
= gate drive operating current (A)
V
g
Q
= FET gate charge, from the FET datasheet (C)
f = switching frequency (Hz)
VBST = boost pin voltage during t
ON
(V)
D = duty cycle
VTTIN = input voltage for VTT LDO (V)
ITT = maximum VTT current (A)
Inserting the following values for VBAT
condition (since
this is the worst case condition for power dissipation in
the controller) as an example):
T
A
= 85°C
θ
= 29°C/W
VCCA = VDDP = 5V
I
VCCA
= 2500μA (data sheet maximum)
I
VDDP
= 150μA (data sheet maximum)
V
g
Q
= 60nC
f = 366kHz
VBAT
(MIN)
= 8V
VBST
(MIN)
= VBAT
(MIN)
+VDDP = 13V
D
VDDQ = VTTIN = 1.8V
VTT = 0.9V
ITT = 1.2A
gives us:
(
8
)
W
206
.
2
9
225
.
mA
1
13
e
=
366
e
60
5
e
150
5
e
2500
5
P
+
3
9
6
6
D
+
+
+
=
and therefore:
=
C
120
29
206
.
+
85
T
J
°
=
As can be seen, the heating effects due to internal power
dissipation are dominated by the VTT LDO, but they can
be managed comfortably by the MLPQ-24 package which
is heatsunk to the ground plane using 4 vias from its
thermal pad.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| SC488 | Complete DDR1/2/3 Memory Power Supply |
| SC488MLTRT | Complete DDR1/2/3 Memory Power Supply |
| SC4901 | COMBI-SYNC Secondary Side Synchronous Rectifier and Regulator |
| SC4901ITSTRT | COMBI-SYNC Secondary Side Synchronous Rectifier and Regulator |
| SC4905A_06 | High Performance Voltage Mode PWM Controller |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| SC486IMLTRT | 制造商:Semtech Corporation 功能描述:Controller IC Leaded Process Compatible: |
| SC486IMLTRT/KO | 制造商:Semtech Corporation 功能描述: |
| SC488 | 制造商:SEMTECH 制造商全稱:Semtech Corporation 功能描述:Complete DDR1/2/3 Memory Power Supply |
| SC488ML.TRT | 制造商:SEMTECH 功能描述:I.C. |
| SC488MLTRT | 制造商:SEMTECH 制造商全稱:Semtech Corporation 功能描述:Complete DDR1/2/3 Memory Power Supply |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。