參數(shù)資料
型號: FAN1585AMX
廠商: FAIRCHILD SEMICONDUCTOR CORP
元件分類: 基準(zhǔn)電壓源/電流源
英文描述: 5A Adjustable/Fixed Low Dropout Linear Regulator
中文描述: 1.5 V-3.6 V ADJUSTABLE POSITIVE LDO REGULATOR, 1.3 V DROPOUT, PSSO3
封裝: PLASTIC, TO-263, 3 PIN
文件頁數(shù): 7/12頁
文件大?。?/td> 63K
代理商: FAN1585AMX
PRODUCT SPECIFICATION
FAN1585A
REV. 1.1.5 11/7/03
7
Figure 11. Basic Regulator Circuit
Load Regulation
It is not possible to provide true remote load sensing because
the FAN1585A series are three-terminal devices. Load regu-
lation is limited by the resistance of the wire connecting the
regulators to the load. Load regulation per the data sheet
specification is measured at the bottom of the package.
For fixed voltage devices, negative side sensing is a true
Kelvin connection with the ground pin of the device returned
to the negative side of the load. This is illustrated in Figure 12.
Figure 12. Connection for Best Load Regulation
For adjustable voltage devices, negative side sensing is a true
Kelvin connection with the bottom of the output divider
returned to the negative side of the load. The best load regu-
lation is obtained when the top of the resistor divider R1 con-
nects directly to the regulator output and not to the load.
Figure 13 illustrates this point.
If R1 connects to the load, then the effective resistance
between the regulator and the load would be:
R
P
x (1 + R2/R1), R
P
= Parasitic Line Resistance
The connection shown in Figure 13 does not multiply R
P
by
the divider ratio. As an example, R
P
is about four milliohms
per foot with 16-gauge wire. This translates to 4mV per foot
at 1A load current. At higher load currents, this drop repre-
sents a significant percentage of the overall regulation. It is
important to keep the positive lead between the regulator and
the load as short as possible and to use large wire or PC
board traces.
Figure 13. Connection for Best Load Regulation
Thermal Considerations
The FAN1585A series protect themselves under overload
conditions with internal power and thermal limiting circuitry.
However, for normal continuous load conditions, do not
exceed maximum junction temperature ratings. It is impor-
tant to consider all sources of thermal resistance from junc-
tion-to-ambient. These sources include the junction-to-case
resistance, the case-to-heat sink interface resistance, and the
heat sink resistance. Thermal resistance specifications have
been developed to more accurately reflect device tempera-
ture and ensure safe operating temperatures.
For example, look at using an FAN1585AT to generate 5A
@ 1.5V ± 2% from a 3.3V source (3.2V to 3.6V).
Assumptions:
V
IN
= 3.6V worst case
V
OUT
= 1.46V worst case
I
OUT
= 5A continuous
T
A
= 50
°
C
θ
Case-to-Ambient
= 3
°
C/W (assuming both a heatsink and
a thermally conductive material)
The power dissipation in this application is:
P
D
= (V
IN
– V
OUT
) * (I
OUT
) = (3.6 – 1.46) * (5) = 10.7W
From the specification table:
T
J
= T
A
+ (P
D
) * (
θ
Case-to-Ambient
+
θ
JC
)
= 50 + (10.7) * (3 + 3) = 115
°
C
The junction temperature is below the maximum rating.
FAN1585A
ADJ
I
ADJ
35
μ
A
R2
R1
C2
22
μ
F
V
OUT
V
REF
+
C1
22
μ
F
+
IN
V
OUT
= V
REF
(1 + R2/R1) + I
ADJ
(R2)
OUT
V
IN
FAN1585A-1.5
GND
R
L
R
P
PARASITIC
LINE RESISTANCE
IN
OUT
V
IN
FAN1585A
ADJ
R2*
CONNECT R1 TO CASE
CONNECT R2 TO LOAD
*
R1*
R
L
R
P
PARASITIC
LINE RESISTANCE
IN
OUT
V
IN
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FAN1585AT 功能描述:低壓差穩(wěn)壓器 - LDO 5a Linear Regulator RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動電壓(最大值):307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
FAN1585AT-1.5 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Positive Fixed Voltage Regulator
FAN1585AT15 功能描述:低壓差穩(wěn)壓器 - LDO U 512-FAN1585AT15_35 RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動電壓(最大值):307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
FAN1585AT15_35 功能描述:低壓差穩(wěn)壓器 - LDO 3-Terminal 5A RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動電壓(最大值):307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
FAN1585AT15_36 功能描述:低壓差穩(wěn)壓器 - LDO U 512-FAN1585AT15_35 RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動電壓(最大值):307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20