- 您現(xiàn)在的位置：買(mǎi)賣(mài)IC網(wǎng) > PDF目錄375160 > A8450 (Allegro MicroSystems, Inc.) Automotive Multioutput Voltage Regulator PDF資料下載
參數(shù)資料
| 型號(hào)： | A8450 |
| 廠商： | Allegro MicroSystems, Inc. |
| 英文描述： | Automotive Multioutput Voltage Regulator |
| 中文描述： | 汽車(chē)Multioutput穩(wěn)壓器 |
| 文件頁(yè)數(shù)： | 13/15頁(yè) |
| 文件大?。?/td> | 549K |
| 代理商： | A8450 |
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)當(dāng)前第13頁(yè)第14頁(yè)第15頁(yè)
13
A8450KLB-DS, Rev. 1
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
115 Northeast Cutoff, Box 15036
Allegro MicroSystems, Inc.
A8450
Automotive Multioutput Voltage Regulator
A8450 Power Dissipation
. The A8450 is designed to
operate in applications with high ambient temperatures. The
total power dissipated in the device must be considered in
conjunction with the thermal dissipation capabilities of the
PCB where the A8450 is mounted, as well as the capabilities
of the device package itself.
The ability of a package to dissipate heat is approximated by
the thermal resistance from the die (junction) to the ambi-
ent environment, R
θ
JA
(°C/W). This includes the significant
effect of dissipation through the package leads and the PCB
on which the package is mounted, and the temperature of the
ambient air. Test results for this 24-lead SOIC are approxi-
mately 35 °C/W when mounted on a high-thermally conduc-
tive PCB (based on the JEDEC standard PCB, having four
layers with buried copper areas).
The total power that can be applied to the device, P
D(lim)
(W),
is affected by the maximum allowable device junction
temperature, T
J(max)
(°C), R
θ
JA
, and the ambient air tempera-
ture, T
A
(°C), as shown in the following formula
P
D(lim)
J(max)
– T
A
)
R
θ
JA
P
D(lim)
can be estimated based on several parameters, using
the following formula
P
D(lim)
= P
D(Ibias)
+ P
D(V5A)
+ P
D(V5D)
+ P
D(buckdc)
+ P
D(buckac)
+ P
D(BD)
where
P
D(Ibias)
= V
BB
×
I
BB
P
D(V5A)
= (V
REG
– 5 V)
×
I
LOAD(V5A)
P
D(V5D)
= (V
REG
– 5 V)
×
I
LOAD(V5D)
P
D(buckdc)
= I
LOAD2
×
R
DSON(TJmax)
×
DC
P
D(buckac)
= I
LOAD
×
[V
BB
( 5 ns
14 V)
×
V
BB
]
×
0.5 f
PWM
P
D(BD)
= I
V33BD(max)
×
(V
REG
– 4 V) + I
VADJBD(max)
×
(V
REG
– V
ADJ
– 0.7 V)
and
I
LOAD
= I
LOAD(V33)
+ I
LOAD(VADJ)
+ I
LOAD(V5D)
+ I
LOAD(V5A)
R
DSON
is a function of T
J
. For the purposes of estimating
P
D(lim)
, the relationship can be assumed to be linear through-
out the practical T
J
operating range (see test conditions for
R
DSON
in the Electrical Characteristics table).
DC (duty cycle) is a function of V
BB
and V
REG
. This can be
calculated precisely as
DC = V
REG(off)
(V
REG(on)
+ V
REG(off)
)
A rough estimate for DC is
DC = (V
REG
+ V
LX
)
V
BB
I
V33BD(max)
is the maximum current drawn on the V33BD
pin. It is dependent on I
OUTV33
and the h
FE
of the pass tran-
sistor.
I
ADJBD(max)
is the maximum current drawn on the VADJBD
pin. It is dependent on I
OUTVADJ
and the h
FE
of the pass
transistor.
Overcurrent Protection
The current supplied by the 3.3 V and the 1.2 to 3.3 V adjust-
able regulators is limited to
I
CL
. Current above
I
CL
is folded
back linearly, as shown in figure 4b. In the case of a shorted
load, the collector current is reduced to 40% of
I
CL
±10% ,
to ensure protection of the pass transistors. After the short is
removed, the voltage recovers to its regulated level.
The maximum power dissipated in the transistor during a
shorted load condition is:
P
D
≈
(
V
REG
–
V
OUT
)
×
(0.4
×
I
CL
)
where V
OUT
= 0 V.
Low Input Voltage Operation
When the charge pump has ramped enough to enhance
the buck switch, the buck converter switching regulator is
enabled. This occurs at V
BB
≈
5.7 V. At that point, the duty
cycle, DC, of the A8450 can be forced to 100% until V
IN
is
high enough to allow the switch to begin operating normally.
The point at which normal switching begins is dependent
on ambient temperature, T
A
. Increases in T
A
cause R
DSON
to
increase. Other significant factors are I
LOAD
, V
REG
, the ESR
of the output inductor (L1), and the forward biasing voltage
for the output Schottky diode (D1).
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| A8450KLB | Automotive Multioutput Voltage Regulator |
| A8483 | 1.2 MHz Step-up Converter for Display Bias Supply |
| A8483EEKTR-T | 1.2 MHz Step-up Converter for Display Bias Supply |
| A8499SLJTR-T | High Voltage Step-Down Regulator |
| A8499 | High Voltage Step-Down Regulator |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| A8450KLB | 功能描述:IC REG QD BUCK/LINEAR 24-SOIC RoHS:否 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 拓?fù)?降壓（降壓）同步（2），線性（LDO）（1） 功能:任何功能 輸出數(shù):3 頻率 - 開(kāi)關(guān):300kHz 電壓/電流 - 輸出 1:控制器 電壓/電流 - 輸出 2:控制器 電壓/電流 - 輸出 3:控制器 帶 LED 驅(qū)動(dòng)器:無(wú) 帶監(jiān)控器:無(wú) 帶序列發(fā)生器:是 電源電壓:4.5 V ~ 24 V 工作溫度:-40°C ~ 85°C 安裝類(lèi)型:* 封裝/外殼:28-TSSOP（0.173"，4.40mm 寬） 供應(yīng)商設(shè)備封裝:* 包裝:帶卷 (TR) 其它名稱(chēng):ISL6402IVZ-TTR |
| A8450KLB-T | 功能描述:IC REG QD BUCK/LINEAR 24-SOIC RoHS:是 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 拓?fù)?降壓（降壓）同步（2），線性（LDO）（1） 功能:任何功能 輸出數(shù):3 頻率 - 開(kāi)關(guān):300kHz 電壓/電流 - 輸出 1:控制器 電壓/電流 - 輸出 2:控制器 電壓/電流 - 輸出 3:控制器 帶 LED 驅(qū)動(dòng)器:無(wú) 帶監(jiān)控器:無(wú) 帶序列發(fā)生器:是 電源電壓:4.5 V ~ 24 V 工作溫度:-40°C ~ 85°C 安裝類(lèi)型:* 封裝/外殼:28-TSSOP（0.173"，4.40mm 寬） 供應(yīng)商設(shè)備封裝:* 包裝:帶卷 (TR) 其它名稱(chēng):ISL6402IVZ-TTR |
| A8450KLB-T | 制造商:Allegro MicroSystems 功能描述:Voltage Regulator IC |
| A8450KLBTR | 功能描述:IC REG QD BUCK/LINEAR 24-SOIC RoHS:否 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 拓?fù)?降壓（降壓）同步（2），線性（LDO）（1） 功能:任何功能 輸出數(shù):3 頻率 - 開(kāi)關(guān):300kHz 電壓/電流 - 輸出 1:控制器 電壓/電流 - 輸出 2:控制器 電壓/電流 - 輸出 3:控制器 帶 LED 驅(qū)動(dòng)器:無(wú) 帶監(jiān)控器:無(wú) 帶序列發(fā)生器:是 電源電壓:4.5 V ~ 24 V 工作溫度:-40°C ~ 85°C 安裝類(lèi)型:* 封裝/外殼:28-TSSOP（0.173"，4.40mm 寬） 供應(yīng)商設(shè)備封裝:* 包裝:帶卷 (TR) 其它名稱(chēng):ISL6402IVZ-TTR |
| A8450KLBTR-T | 功能描述:IC REG QD BUCK/LINEAR 24-SOIC RoHS:是 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 拓?fù)?降壓（降壓）同步（3），線性（LDO）（2） 功能:任何功能 輸出數(shù):5 頻率 - 開(kāi)關(guān):300kHz 電壓/電流 - 輸出 1:控制器 電壓/電流 - 輸出 2:控制器 電壓/電流 - 輸出 3:控制器 帶 LED 驅(qū)動(dòng)器:無(wú) 帶監(jiān)控器:無(wú) 帶序列發(fā)生器:是 電源電壓:5.6 V ~ 24 V 工作溫度:-40°C ~ 85°C 安裝類(lèi)型:* 封裝/外殼:* 供應(yīng)商設(shè)備封裝:* 包裝:* |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。