参数资料
型号: MAX1715EEI
厂商: Maxim Integrated Products
文件页数: 21/25页
文件大小: 0K
描述: IC REG CTRLR BUCK PWM 28-QSOP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 50
PWM 型: 控制器
输出数: 2
频率 - 最大: 620kHz
占空比: 100%
电源电压: 4.5 V ~ 5.5 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 85°C
封装/外壳: 28-SSOP(0.154",3.90mm 宽)
包装: 管件
Ultra-High Efficiency, Dual Step-Down
Controller for Notebook Computers
V BATT
OUT1
OUT2
2.5V
1/2
MAX1715
DH
V OUT
FIXED
1.8V
FIXED
3.3V
TO ERROR
AMP1
TO ERROR FIXED
AMP2
DL
PGND
OUT
FB
R1
FB1
0.2V
0.2V
FB2
R2
V OUT FB ? 1 +
= V
?
R2 ?
AGND
Figure 8. Setting V OUT with a Resistor-Divider
when going abruptly from full-load to no-load condi-
tions, unless there are some bulk tantalum or electrolyt-
ic capacitors in parallel to absorb the stored energy in
the inductor. In some cases, there may be no room for
electrolytics, creating a need for a DC-DC design that
uses nothing but ceramics.
The all-ceramic-capacitor application of Figure 8
replaces the standard tantalum output capacitors with
ceramics. This design relies on having a minimum of
5m Ω parasitic PC board trace resistance in series with
the capacitor to reduce the ESR zero frequency. This
small amount of resistance is easily obtained by locat-
ing the MAX1714A circuit 2 or 3 inches away from the
CPU, and placing all the ceramic capacitors close to
the CPU. Resistance values higher than 5m Ω just
improve the stability (which can be observed by exam-
ining the load-transient response characteristic as
shown in the Typical Operating Characteristics ). Avoid
adding excess PC board trace resistance, as there’s an
efficiency penalty; 5m Ω is sufficient for a 7A circuit:
MAX1715
2V
Figure 9. Feedback Mux
penalty for operating at 540kHz is about 2% to 3%,
depending on the input voltage.
An optional 1 Ω resistor is placed in series with OUT.
This resistor attenuates high-frequency noise in some
bands, which causes double pulsing.
Fixed Output Voltages
The MAX1715 ’s Dual Mode ? operation allows the
selection of common voltages without requiring external
components (Figure 9). Connect FB to AGND for a
fixed +2.5V output or to V CC for a +3.3V output, or con-
nect FB directly to OUT for a fixed +1.0V output.
Setting V OUT with a Resistor-Divider
The output voltage can be adjusted with a resistor-
divider if desired (Figure 8). The equation for adjusting
the output voltage is:
? R1 ?
?
where V FB is 1.0V and R2 is about 10k Ω .
R ESR ≥
1
2FC OUT
Two-Stage (5V-Powered) Notebook
CPU Buck Regulator
Output overshoot ( Δ V) determines the minimum output
capacitance requirement. In this example, the switch-
ing frequency has been increased to 600kHz and the
inductor value has been reduced to 0.5μH (compared
to 300kHz and 2μH for the standard 8A circuit) to mini-
mize the energy transferred from inductor to capacitor
during load-step recovery. The overshoot must be cal-
culated to avoid tripping the OVP latch. The efficiency
Dual Mode is a trademark of Maxim Integrated Products.
The most efficient and overall cost-effective solution for
stepping down a high-voltage battery to a very low out-
put voltage is to use a single-stage buck regulator
that’s powered directly from the battery. However, there
may be situations where the battery bus can’t be routed
near the CPU, or where space constraints dictate the
smallest possible local DC-DC converter. In such
cases, the 5V-powered circuit of Figure 10 may be
appropriate. The reduced input voltage allows a higher
______________________________________________________________________________________
21
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MAX1715EEI+ 功能描述:DC/DC 开关控制器 Dual Step-Down Controller 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
MAX1715EEI+T 功能描述:DC/DC 开关控制器 Dual Step-Down Controller 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
MAX1715EEI-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
MAX1715EVKIT 功能描述:DC/DC 开关控制器 Evaluation Kit for the MAX1715 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 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