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参数资料
| 型号： | MAX8720ETX+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 17/31页 |
| 文件大小： | 0K |
| 描述： | IC CNTRL VID STP DWN 36-TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 应用： | 控制器，CPU GPU |
| 输入电压： | 2 V ~ 28 V |
| 输出数： | 1 |
| 输出电压： | 0.28 V ~ 1.85 V |
| 工作温度： | 0°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 36-WFQFN 裸露焊盘 |
| 供应商设备封装： | 36-TQFN 裸露焊盘（6x6） |
| 包装： | 带卷 (TR) |
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Dynamically Adjustable 6-Bit VID
Step-Down Controller
? I
? t
=
V IN - V OUT
L
I PEAK
I PEAK
I LOAD
( LIR2 )
I LOAD = I PEAK / 2
I LIM(VAL) = I LOAD(MAX) 1-
I LIMIT
0
ON-TIME
TIME
0
TIME
Figure 3. Pulse-Skipping/Discontinuous Crossover Point
Figure 4. Valley Current-Limit Threshold
V GS ( TH ) > V IN ? RSS ?
? C ?
? C ISS ?
Lot-to-lot variation of the threshold voltage can cause
problems in marginal designs. Typically, adding
4700pF between DL and power ground (C NL in Figure
MAX8720
V DD
BST
(R BST )*
C BYP
D BST
5), close to the low-side MOSFETs, greatly reduces
coupling. Do not exceed 22nF of total gate capacitance
to prevent excessive turn-off delays.
Alternatively, shoot-through currents may be caused by
a combination of fast high-side MOSFETs and slow low-
side MOSFETs. If the turn-off delay time of the low-side
V DD
DH
LX
C BST
N H
INPUT (V IN )
L
MOSFET is too long, the high-side MOSFETs can turn
on before the low-side MOSFETs have actually turned
off. Adding a resistor less than 5 ? in series with BST
slows down the high-side MOSFETs’ turn-on time, elimi-
DL
PGND
(C NL )*
N L
nating the shoot-through currents without degrading
the turn-off time (R BST in Figure 5). Slowing down the
high-side MOSFETs also reduces the LX node rise
time, thereby reducing EMI and high-frequency cou-
pling responsible for switching noise.
V CC POR and UVLO
Power-on reset (POR) occurs when V CC rises above
approximately 2V, resetting the fault latch and prepar-
ing the PWM for operation. V CC undervoltage-lockout
(UVLO) circuitry inhibits switching, forces PGOOD low,
and forces the DL gate driver low. When V CC rises
above 4.2V, the DAC inputs are sampled and the out-
put voltage begins to slew to the DAC setting.
If V CC drops low enough to trip the UVLO comparator, it
is assumed that there is not enough supply voltage to
make valid decisions. The MAX8720 immediately forces
both DH and DL low. The output discharges to 0V at a
(R BST )* OPTIONAL—THE RESISTOR LOWERS EMI BY DECREASING
THE SWITCHING-NODE RISE TIME.
(C NL )* OPTIONAL—THE CAPACITOR REDUCES LX TO DL CAPACITIVE
COUPLING THAT CAN CAUSE SHOOT-THROUGH CURRENTS.
Figure 5. Reducing the Switching-Node Rise Time
rate dependent on the load and the total output capaci-
tance. This prevents negative output voltages, eliminat-
ing the need for a Schottky diode to GND at the output.
For automatic startup, the battery voltage should be
present before V CC . If the MAX8720 attempts to bring
the output into regulation without the battery voltage
present, the fault latch trips. The SHDN pin can be tog-
gled to reset the fault latch.
______________________________________________________________________________________
17
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX8720EVKIT | 功能描述:DC/DC 开关控制器 Evaluation Kit for the MAX8720 RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| MAX8722AEEG | 功能描述:显示驱动器和控制器 RoHS:否 制造商:Panasonic Electronic Components 工作电源电压:2.7 V to 5.5 V 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:QFN-44 封装:Reel |
| MAX8722AEEG+ | 功能描述:显示驱动器和控制器 CCFL Backlight Controller RoHS:否 制造商:Panasonic Electronic Components 工作电源电压:2.7 V to 5.5 V 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:QFN-44 封装:Reel |
| MAX8722AEEG+T | 功能描述:显示驱动器和控制器 CCFL Backlight Controller RoHS:否 制造商:Panasonic Electronic Components 工作电源电压:2.7 V to 5.5 V 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:QFN-44 封装:Reel |
| MAX8722AEEG-T | 功能描述:显示驱动器和控制器 RoHS:否 制造商:Panasonic Electronic Components 工作电源电压:2.7 V to 5.5 V 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:QFN-44 封装:Reel |
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