參數(shù)資料
型號(hào): MAX799ESE
廠商: MAXIM INTEGRATED PRODUCTS INC
元件分類: 穩(wěn)壓器
英文描述: Octal D-type Edge-Triggered Flip-Flops with 3-State Outputs 20-CDIP -55 to 125
中文描述: SWITCHING CONTROLLER, 350 kHz SWITCHING FREQ-MAX, PDSO16
封裝: SOIC-16
文件頁數(shù): 19/32頁
文件大?。?/td> 319K
代理商: MAX799ESE
M
S tep-Down Controllers with
S ync hronous Rec tifier for CPU Power
______________________________________________________________________________________
19
_________________Design Proc edure
The five pre-designed standard application circuits
(Figure 1 and Table 1) contain ready-to-use solutions
for common applications. Use the following design pro-
cedure to optimize the basic schematic for different
voltage or current requirements. Before beginning a
design, firmly establish the following:
V
IN(MAX)
, the maximum input (battery) voltage.
This
value should include the worst-case conditions, such
as no-load operation when a battery charger or AC
adapter is connected but no battery is installed.
V
IN(MAX)
must not exceed 30V. This 30V upper limit is
determined by the breakdown voltage of the BST float-
ing gate driver to GND (36V absolute maximum).
V
IN(MIN)
, the minimum input (battery) voltage.
This
should be taken at full-load under the lowest battery
conditions. If V
IN(MIN)
is less than 4.5V, a special circuit
must be used to externally hold up VL above 4.8V. If
the minimum input-output difference is less than 1.5V,
the filter capacitance required to maintain good AC
load regulation increases.
Induc tor V alue
The exact inductor value isn’t critical and can be
adjusted freely in order to make tradeoffs among size,
cost, and efficiency. Although lower inductor values will
minimize size and cost, they will also reduce efficiency
due to higher peak currents. To permit use of the physi-
cally smallest inductor, lower the inductance until the
circuit is operating at the border between continuous
and discontinuous modes. Reducing the inductor value
even further, below this crossover point, results in dis-
continuous-conduction operation even at full load. This
helps reduce output filter capacitance requirements but
causes the core energy storage requirements to
increase again. On the other hand, higher inductor val-
ues will increase efficiency, but at some point resistive
losses due to extra turns of wire will exceed the benefit
gained from lower AC current levels. Also, high induc-
tor values can affect load-transient response; see the
V
SAG
equation in the Low-Voltage Operationsection.
The following equations are given for continuous-con-
duction operation since the MAX796 is mainly intended
for high-efficiency battery-powered applications. See
Appendix A in Maxim’s Battery Management and DC-
DC Converter Circuit Collection for crossover point and
discontinuous-mode equations. Discontinuous conduc-
tion doesn’t affect normal idle-mode operation.
MAX799
NEGATIVE
SECONDARY
OUTPUT
MAIN
OUTPUT
DH
V+
SECFB
R3
R2
1-SHOT
TRIG
DL
0.33
μ
F
REF
MAX796
POSITIVE
SECONDARY
OUTPUT
MAIN
OUTPUT
DH
V+
SECFB
2.505V REF
R3
R2
1-SHOT
TRIG
DL
+V
TRIP
WHERE V
REF
(NOMINAL) = 2.505V
= V
REF
(
1 + R3
)
-V
TRIP
R3 = 100k
(RECOMMENDED)
= -V
REF
(
R3
)
Figure 9. Secondary-Output Feedback Dividers, MAX796 vs. MAX799
相關(guān)PDF資料
PDF描述
MAX797HESE High-Voltage, Step-Down Controller with Synchronous Rectifier for CPU Power
MAX799MJE Step-Down Controllers with Synchronous Rectifier for CPU Power
MAX802 3.0V/3.3V Microprocessor Supervisory Circuits(具有看門狗和支持備用電池,高精度復(fù)位器)
MAX805 3.0V/3.3V Microprocessor Supervisory Circuits(具有看門狗和支持備用電池的復(fù)位器(高電壓復(fù)位))
MAX704 3.0V/3.3V Microprocessor Supervisory Circuits(支持備用電池復(fù)位器,復(fù)位門限4.40V)
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX799ESE+ 制造商:Maxim Integrated Products 功能描述:CONV DC-DC SGL-OUT STEP DOWN 16SOIC N - Rail/Tube
MAX799ESE+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
MAX799ESE-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
MAX799MJE 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
MAX8 制造商:Lanzar 功能描述:4Ohm 600W Peak 8 Paper Cone Woofer 制造商:LANZAR 功能描述:8 PAPER CONE WOOFER 4OHM 600W PEAK