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参数资料
| 型号： | MAX1716EEG+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 28/33页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 24-QSOP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 50 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 550kHz |
| 占空比： | 100% |
| 电源电压： | 2 V ~ 28 V |
| 降压： | 是 |
| 升压： | 无 |
| 回扫： | 无 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 24-SSOP（0.154"，3.90mm 宽） |
| 包装： | 管件 |
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High-Speed, Adjustable, Synchronous Step-Down
Controllers with Integrated Voltage Positioning
er transient response than the single stage, this can be
offset by the use of a voltage-positioned converter.
MAX1716
MAX1854
MAX1855
DH
LX
DL
CS
Q1
Q2
L1
R4
R5
V OUT
Ceramic Output Capacitor Applications
Ceramic capacitors have advantages and disadvan-
tages. They have ultra-low ESR and are noncom-
bustible, relatively small, and nonpolarized. However,
they are also expensive and brittle, and their ultra-low
ESR characteristic can result in excessively high ESR
zero frequencies. In addition, their relatively low capac-
VPS
PGND
R SENSE
itance value can cause output overshoot when step-
ping from full-load to no-load conditions, unless a small
inductor value is used (high switching frequency), or
there are some bulk tantalum or electrolytic capacitors
in parallel to absorb the stored inductor energy. In
some cases, there may be no room for electrolytics,
FB
V OUT = V FB (1 + R4/R5)
Figure 9. Adjusting V OUT with a Resistor-Divider
adjusted with a resistor-divider, the switching frequen-
cy is increased by the inverse of the divider ratio.
This change in frequency can be compensated with the
addition of a resistor-divider to the battery-sense input
(V+). Attach a resistor-divider from the battery voltage
to V+ on the MAX1716/MAX1854/MAX1855, with the
same attenuation factor as the output divider. The V+
input has a nominal input impedance of 600k ? , which
should be considered when selecting resistor values.
One-Stage (Battery Input) vs. Two-Stage
(5V Input) Applications
The MAX1716/MAX1854/MAX1855 can be used with a
direct battery connection (one stage) or can obtain
power from a regulated 5V supply (two stage). Each
approach has advantages, and careful consideration
should go into the selection of the final design.
The one-stage approach offers smaller total inductor
size and fewer capacitors overall due to the reduced
demands on the 5V supply. The transient response of
the single stage is better due to the ability to ramp the
inductor current faster. The total efficiency of a single
stage is better than the two-stage approach.
The two-stage approach allows flexible placement due
to smaller circuit size and reduced local power dissipa-
tion. The power supply can be placed closer to the
CPU for better regulation and lower I 2 R losses from PC
board traces. Although the two-stage design has slow-
creating a need for a DC-DC design that uses nothing
but ceramics.
The MAX1716 can take full advantage of the small size
and low ESR of ceramic output capacitors in a voltage-
positioned circuit. The addition of the positioning resis-
tor increases the ripple at FB, lowering the effective
ESR zero frequency of the ceramic output capacitor.
Output overshoot (V SOAR) determines the minimum out-
put capacitance requirement (see Output Capacitor
Selection ). Often the switching frequency is increased
to 400kHz or 550kHz, and the inductor value is
reduced to minimize the energy transferred from induc-
tor to capacitor during load-step recovery. The efficien-
cy penalty for operating at 400kHz is about 2% to 3%
and about 5% at 550kHz when compared to the
300kHz voltage-positioned circuit, primarily due to the
high-side MOSFET switching losses.
Table 1 and the Typical Operating Characteristics
include a circuit using ceramic capacitors with a
550kHz switching frequency (Figure 13).
PC Board Layout Guidelines
Careful PC board layout is critical to achieve low
switching losses and clean, stable operation. The
switching power stage requires particular attention
(Figure 10). If possible, mount all of the power compo-
nents on the top side of the board with their ground ter-
minals flush against one another. Follow these
guidelines for good PC board layout:
1) Keep the high-current paths short, especially at the
ground terminals. This is essential for stable, jitter-
free operation.
2) Connect all analog grounds to a separate solid cop-
per plane, which connects to the GND pin of the
MAX1716/MAX1854/MAX1855. This includes the
28
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1716EEG+ | 功能描述:DC/DC 开关控制器 Adj Synchronous Step-Down 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 |
| MAX1716EEG+T | 功能描述:DC/DC 开关控制器 Adj Synchronous Step-Down 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 |
| MAX1716EEG-T | 功能描述:DC/DC 开关控制器 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 |
| MAX17175ETG+ | 制造商:Maxim Integrated Products 功能描述:BOOST REG W/INTEGRATED CHARGE PUMPS SWITCH CONTROL & HIGH-CU - Rail/Tube |
| MAX1717BEEG | 功能描述:DC/DC 开关控制器 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 |
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