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参数资料
| 型号： | MAX1830EEE+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 9/13页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC 3A 16QSOP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 类型： | 降压（降压） |
| 输出类型： | 两者兼有 |
| 输出数： | 1 |
| 输出电压： | 1.5V，1.8V，2.5V，可调 |
| 输入电压： | 3 V ~ 5.5 V |
| PWM 型： | 电流模式，混合 |
| 频率 - 开关： | 1MHz |
| 电流 - 输出： | 3A |
| 同步整流器： | 是 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 16-SSOP（0.154"，3.90mm 宽） |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 16-QSOP |
3A, 1MHz, Low-Voltage, Step-Down Regulators with
Synchronous Rectification and Internal Switches
Table 2. Output Voltage Programming
evenly distribute the copper area connected at the IC
among the high-current pins.
FBSEL
PIN
FB
OUTPUT VOLTAGE (V)
MAX1830 MAX1831
Power Dissipation
Power dissipation in the MAX1830/MAX1831 is domi-
V CC
Unconnected
Output voltage
Output voltage
2.5
1.5
2.5
1.5
nated by conduction losses in the two internal power
switches. Power dissipation due to supply current in the
REF
GND
Output voltage
Resistive divider
1.8 3.3
Adjustable
control section and average current used to charge
and discharge the gate capacitance of the internal
switches (i.e., switching losses) is approximately:
P DS = C x V IN2 x f PWM
where C = 5nF and f PWM is the switching frequen-
MAX1830
MAX1831
R1 = 30k ?
R2 = R1(V OUT / V REF - 1)
LX
FB
R2
R1
V OUT
cy in PWM mode.
This number is reduced when the switching frequency
decreases as the part enters Idle Mode. Combined con-
duction losses in the two power switches are approxi-
mated by:
P D = I OUT2 x R PMOS
where R PMOS is the on-resistance of the PMOS switch.
The junction-to-ambient thermal resistance required to
dissipate this amount of power is calculated by:
V REF = 1.1V
Figure 4. Adjustable Output Voltage
Synchronous Rectification
In a step-down regulator without synchronous rectifica-
tion, an external Schottky diode provides a path for cur-
rent to flow when the inductor is discharging. Replacing
the Schottky diode with a low-resistance NMOS syn-
chronous switch reduces conduction losses and
improves efficiency.
The NMOS synchronous-rectifier switch turns on follow-
ing a short delay after the PMOS power switch turns off,
thus preventing cross conduction or “ shoot through. ” In
constant-off-time mode, the synchronous-rectifier
switch turns off just prior to the PMOS power switch
turning on. While both switches are off, inductor current
flows through the internal-body diode of the NMOS
switch. The internal-body diode ’ s forward voltage is rel-
atively high. An external Schottky diode from PGND to
LX can improve efficiency.
Thermal Resistance
Junction-to-ambient thermal resistance, θ JA , is highly
dependent on the amount of copper area immediately
surrounding the IC leads. The MAX1830/MAX1831
evaluation kit has 0.7in 2 of copper area and a thermal
resistance of +71 ° C/W with no forced airflow. Airflow
over the board significantly reduces the junction-to-
ambient thermal resistance. For heatsinking purposes,
θ JA = (T J,MAX - T A,MAX ) / P D(T OT )
where:
θ JA = junction-to-ambient thermal resistance
T J,MAX = maximum junction temperature
T A,MAX = maximum ambient temperature
P D(TOT) = total losses
Design Procedure
For typical applications, use the recommended compo-
nent values in Table 1. For other applications, take the
following steps:
1) Select the desired PWM-mode switching frequency;
1MHz is a good starting point. See Figure 3 for maxi-
mum operating frequency.
2) Select the constant off-time as a function of input
voltage, output voltage, and switching frequency.
3) Select R TOFF as a function of off-time.
4) Select the inductor as a function of output voltage,
off-time, and peak-to-peak inductor current.
Setting the Output Voltage
The output of the MAX1830/MAX1831 is selectable
between one of three preset output voltages. For a pre-
set output voltage, connect FB to the output voltage
and connect FBSEL as indicated in Table 2. For an
adjustable output voltage, connect FBSEL to GND and
connect FB to a resistive divider between the output
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相关代理商/技术参数 |
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| MAX1830EVKIT | 功能描述:电源管理IC开发工具 RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
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| MAX1831EEE | 功能描述:直流/直流开关调节器 RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| MAX1831EEE+ | 功能描述:直流/直流开关调节器 3A 1MHz Step-Down RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| MAX1831EEE+T | 功能描述:直流/直流开关调节器 3A 1MHz Step-Down RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
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