參數(shù)資料
型號: AAT2550
廠商: Advanced Analog Technology,lnc.
英文描述: Total Power Solution for Portable Applications
中文描述: 總功率便攜式應(yīng)用解決方案
文件頁數(shù): 27/35頁
文件大?。?/td> 914K
代理商: AAT2550
Total Power Loss Examples
The most likely high power scenario is when the
charger and step-down converter are both opera-
tional and powered from the adapter. To examine
the step-down converter maximum current capabil-
ity for this condition, it is necessary to determine
the step-down converter MOSFET R
DS(ON)
, quies-
cent current, and switching losses at the adapter
voltage level (5V). This example shows that with a
600mA battery charge current, the buck converter
output current capability is limited 400mA. This lim-
its the junction temperature to 110°C and avoids
the thermal loop charge reduction at a 70°C ambi-
ent temperature.
Conditions:
V
OA
2.5V @
400mA
1.8V @
400mA
70μA
Step-Down Converter A
V
OB
Step-Down Converter B
I
Q
Converter Quiescent
Current
Charger and Step-Down
Converter Input Voltage
Battery Preconditioning
Threshold Voltage
Battery Charge Current
Charger Operating Current
V
IN
=
V
ADP
V
MIN
5.0V
3.0V
I
CH
I
OP
0.6A
0.75mA
AAT2550
Total Power Solution for Portable Applications
2550.2006.07.1.0
27
T
J(MAX)
= T
AMB
+
θ
JA
· P
LOSS
= 70°C + (28°C/W) · 1.38W
= 108°C
P
TOTAL
=
+ (
t
SW
· F
S
· (
I
OA
+ I
OB
)
+ 2 ·
I
Q
) ·
V
IN
+ (V
ADP
- V
MIN
) · I
CH
+ V
ADP
· I
OP
+ 2 · (
5ns
· 1.4MHz ·
0.4A
+ 70μA) ·
5.0V + (5.0V - 3.0V) · 0.6A + 5.0V · 0.75mA = 1.38W
=
I
OA2
·
(R
DS(ON)H
· V
OA
+
R
DS(ON)L
· (V
IN
- V
OA
)) + I
OB2
·
(R
DS(ON)H
· V
OB
+
R
DS(ON)L
· (V
IN
- V
OB
))
V
IN
0.4A
2
·
(0.475
Ω
· 2.5V
+
0.45
Ω
· (5.0V - 2.5V)) + 0.4A
2
·
(0.475
Ω
· 1.8V
+
0.45
Ω
· (5.0V - 1.8V))
5.0V
The step-down converter load current capability is
greatest when the battery charger is disabled. The
following example demonstrates the junction tem-
perature rise for conditions where the battery charg-
er is disabled and full load is applied to both con-
verter outputs at the nominal battery input voltage.
Conditions:
V
O1
2.5V @
600mA
1.8V @
600mA
70μA
Step-Down Converter A
V
O2
Step-Down Converter B
I
Q
Converter Quiescent
Current
Charger and Step-Down
Converter Input Voltage
Charger Disabled
V
IN
3.6V
I
CH
=
I
OP
0A
相關(guān)PDF資料
PDF描述
AAT2554 Total Power Solution for Portable Applications
AAT2554IRN-CAP-T1 Total Power Solution for Portable Applications
AAT2554IRN-CAQ-T1 Total Power Solution for Portable Applications
AAT2554IRN-CAT-T1 Total Power Solution for Portable Applications
AAT2554IRN-CAW-T1 Total Power Solution for Portable Applications
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AAT2550_08 制造商:ANALOGICTECH 制造商全稱:Advanced Analogic Technologies 功能描述:Total Power Solution for Portable Applications
AAT2550ISK-CAA-T1 制造商:Skyworks Solutions Inc 功能描述:Voltage Regulators - Switching Regulators 2 step-down conv + battery charger 制造商:Skyworks Solutions Inc 功能描述:DC TO DC CONVERTER
AAT2552 制造商:ANALOGICTECH 制造商全稱:Advanced Analogic Technologies 功能描述:Total Power Solution for Portable Applications
AAT2552_08 制造商:ANALOGICTECH 制造商全稱:Advanced Analogic Technologies 功能描述:Total Power Solution for Portable Applications
AAT2552IRN-CAE-T1 功能描述:電荷泵 Total Pwr Solution for Portable App RoHS:否 制造商:Maxim Integrated 功能:Inverting, Step Up 輸出電壓:- 1.5 V to - 5.5 V, 3 V to 11 V 輸出電流:100 mA 電源電流:1 mA 最大工作溫度:+ 70 C 封裝 / 箱體:SOIC-8 Narrow 封裝:Tube