- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383339 > MAX1876 (Maxim Integrated Products, Inc.) Fixed-Point Digital Signal Processor 288-BGA MICROSTAR PDF資料下載
參數(shù)資料
| 型號： | MAX1876 |
| 廠商： | Maxim Integrated Products, Inc. |
| 元件分類： | 數(shù)字信號處理 |
| 英文描述： | Fixed-Point Digital Signal Processor 288-BGA MICROSTAR |
| 中文描述： | 雙路、180°異相、PWM降壓型控制器，帶有POR |
| 文件頁數(shù)： | 17/21頁 |
| 文件大?。?/td> | 493K |
| 代理商： | MAX1876 |
Minimum threshold voltage (V
TH(MIN)
)
Total gate charge (Q
g
)
Reverse transfer capacitance (C
RSS
)
Power dissipation
All four N-channel MOSFETs must be a logic-level type
with guaranteed on-resistance specifications at V
GS
≥
4.5V. For maximum efficiency, choose a high-side
MOSFET (N
H
_) that has conduction losses equal to the
switching losses at the optimum input voltage. Check to
ensure that the conduction losses at minimum input
voltage do not exceed MOSFET package thermal limits,
or violate the overall thermal budget. Also, check to
ensure that the conduction losses plus switching losses
at the maximum input voltage do not exceed package
ratings or violate the overall thermal budget.
Ensure that the MAX1875/MAX1876 DL_ gate drivers
can drive N
L
_. In particular, check that the dv/dt
caused by N
H
_ turning on does not pull up the N
L
_
gate through N
L
_
’
s drain-to-gate capacitance. This is
the most frequent cause of cross-conduction problems.
Gate-charge losses are dissipated by the driver and do
not heat the MOSFET. All MOSFETs must be selected
so that their total gate charge is low enough that V
L
can
power all four drivers without overheating the IC:
MOSFET package power dissipation often becomes a
dominant design factor. I
2
R power losses are the great-
est heat contributor for both high-side and low-side
MOSFETs. I
2
R losses are distributed between N
H
_ and
N
L
_ according to duty factor as shown in the equations
below. Switching losses affect only the high-side
MOSFET, since the low-side MOSFET is a zero-voltage
switched device when used in the buck topology.
Calculate MOSFET temperature rise according to pack-
age thermal-resistance specifications to ensure that
both MOSFETs are within their maximum junction tem-
perature at high ambient temperature. The worst-case
dissipation for the high-side MOSFET (P
NH
) occurs at
both extremes of input voltage, and the worst-case dis-
sipation for the low-side MOSFET (P
NL
) occurs at maxi-
mum input voltage.
I
GATE
is the average DH driver output current capability
determined by:
where R
DS(ON)DH
is the high-side MOSFET driver
’
s on-
resistance (5
max), and R
GATE
is any series resis-
tance between DH and BST (Figure 3).
where P
NH(CONDUCTION)
is the conduction power loss
in the high-side MOSFET, and P
NL
is the total low-side
power loss.
To reduce EMI caused by switching noise, add a 0.1μF
ceramic capacitor from the high-side switch drain to
the low-side switch source or add resistors in series
with DL_ and DH_ to increase the MOSFETs
’
turn-on
and turn-off times.
Applications Information
Dropout Performance
When working with low input voltages, the output-volt-
age adjustable range for continuous-conduction opera-
tion is restricted by the minimum off-time (t
OFF(MIN)
).
For best dropout performance, use the lowest (100kHz)
switching-frequency setting. Manufacturing tolerances
and internal propagation delays introduce an error to
P
I
R
V
V
P
P
P
P
I
R
V
V
NH CONDUCTION
(
LOAD
DS ON NH
(
OUT
IN
NH TOTAL
(
NH SWITCHING
(
NH CONDUCTION
(
NL
LOAD
DS ON NL
(
OUT
IN
)
)
)
)
)
)
=
=
+
=
2
2
1-
I
V
R
(
R
GATE
L
DS ON DH
(
GATE
=
+
)
2
)
P
V I
2
f
Q
Q
I
NH SWITCHING
(
GS
GD
GATE
)
=
+
P
V
Q
f
VL
IN
G
TOTAL
SW
=
×
×
_
M
Dual 180° Out-of-Phase PWM Step-
Down Controllers with POR
______________________________________________________________________________________
17
BODE PLOT FOR VOLTAGE-
MODE CONTROLLERS
FREQUENCY (MHz)
G
0.1
0.01
-40
-30
-20
-10
0
10
20
30
40
50
0.001
1
f
Z-COMP_A
f
COMP_B
f
LC
f
CO
f
ESR
f
SWITCH
Figure 8. Voltage-Mode Loop Analysis
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MAX1876AEEG | Fixed-Point Digital Signal Processor 288-BGA MICROSTAR |
| MAX1876EEG | Fixed-Point Digital Signal Processor 288-BGA MICROSTAR |
| MAX1879 | Simple, Efficient, 1-Cell Li+ Pulse Charger |
| MAX1879EUA | Simple, Efficient, 1-Cell Li+ Pulse Charger |
| MAX187ACPA | +5V, Low-Power, 12-Bit Serial ADCs |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MAX1876AEEG | 功能描述:DC/DC 開關(guān)控制器 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 |
| MAX1876AEEG+ | 功能描述:電壓模式 PWM 控制器 Dual 180 Out PWM Step-Down RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓?fù)浣Y(jié)構(gòu):Buck 輸出電壓:34 V 輸出電流: 開關(guān)頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel |
| MAX1876AEEG+T | 功能描述:電壓模式 PWM 控制器 Dual 180 Out PWM Step-Down RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓?fù)浣Y(jié)構(gòu):Buck 輸出電壓:34 V 輸出電流: 開關(guān)頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel |
| MAX1876AEEG-T | 功能描述:DC/DC 開關(guān)控制器 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 |
| MAX1876EEG | 功能描述:DC/DC 開關(guān)控制器 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 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。