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参数资料
| 型号： | MAX15026CATD+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 14/23页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM VM 14TDFN |
| 产品培训模块： | Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| PWM 型： | 电压模式 |
| 输出数： | 1 |
| 频率 - 最大： | 2.4MHz |
| 占空比： | 88% |
| 电源电压： | 4.5 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 ~ 125°C |
| 封装/外壳： | 14-WFDFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
MAX15026
Low-Cost, Small, 4.5V to 28V Wide Operating
Range, DC-DC Synchronous Buck Controller
Connect an external resistor (R LIM ) from LIM to GND to
adjust the current-limit threshold. The relationship
between the current-limit threshold (V ITH ) and R LIM is:
where I P-P is the peak-to-peak inductor current ripple
(see the Inductor Selection section). Use these equa-
tions for initial capacitor selection. Decide on the final
R LIM =
10 × V ITH
50 μ A
values by testing a prototype or an evaluation circuit.
Check the output capacitor against load-transient
response requirements. The allowable deviation of the
where R LIM is in k ? and V ITH is in mV.
An R LIM resistance range of 6k ? to 60k ? corresponds
to a current-limit threshold of 30mV to 300mV. Use 1%
tolerance resistors when adjusting the current limit to
minimize error in the current-limit threshold.
Input Capacitor
The input filter capacitor reduces peak currents drawn
from the power source and reduces noise and voltage
ripple on the input caused by the switching circuitry.
The input capacitor must meet the ripple current
requirement (I RMS ) imposed by the switching currents
as defined by the following equation,
output voltage during fast load transients determines
the capacitor output capacitance, ESR, and equivalent
series inductance (ESL). The output capacitor supplies
the load current during a load step until the controller
responds with a higher duty cycle. The response time
(t RESPONSE ) depends on the closed-loop bandwidth of
the converter (see the Compensation section). The
resistive drop across the ESR of the output capacitor,
the voltage drop across the ESL ( ? V ESL ) of the capaci-
tor, and the capacitor discharge, cause a voltage
droop during the load step.
Use a combination of low-ESR tantalum/aluminum elec-
trolytic and ceramic capacitors for improved transient
I RMS = I LOAD ( MAX )
V OUT ( V IN ? V OUT )
V IN
load and voltage ripple performance. Nonleaded
capacitors and capacitors in parallel help reduce the
ESL. Keep the maximum output voltage deviation below
the tolerable limits of the load. Use the following equa-
? V ESR
C OUT = STEP RESPONSE
ESL =
I RMS attains a maximum value when the input voltage
equals twice the output voltage (V IN = 2V OUT ), so
I RMS(MAX) = I LOAD(MAX) /2. For most applications,
non-tantalum capacitors (ceramic, aluminum, poly-
mer, or OS-CON) are preferred at the inputs due to
the robustness of non-tantalum capacitors to accom-
modate high inrush currents of systems being pow-
ered from very low-impedance sources. Additionally,
two (or more) smaller-value low-ESR capacitors can
be connected in parallel for lower cost.
tions to calculate the required ESR, ESL, and capaci-
tance value during a load step:
ESR =
I STEP
I × t
? V Q
? V E SL × t STEP
I STEP
Output Capacitor
The key selection parameters for the output capacitor are
t RESPONSE ?
1
3 × f O
? V Q =
I P ? P = ? IN O U T ? × ? OUT ?
capacitance value, ESR, and voltage rating. These para-
meters affect the overall stability, output ripple voltage, and
transient response. The output ripple has two components:
variations in the charge stored in the output capacitor, and
the voltage drop across the capacitor’s ESR caused by
the current flowing into and out of the capacitor:
? V RIPPLE ? ? V ESR + ? V Q
The output voltage ripple as a consequence of the ESR
and the output capacitance is:
? V ESR = I P ? P × ESR
I P ? P
8 × C OUT × f SW
? V ? V ? ? V ?
? f SW × L ? ? V IN ?
14
where I STEP is the load step, t STEP is the rise time of the
load step, t RESPONSE is the response time of the con-
troller and f O is the closed-loop crossover frequency.
Compensation
The MAX15026 provides an internal transconductance
amplifier with the inverting input and the output avail-
able for external frequency compensation. The flexibility
of external compensation offers a wide selection of out-
put filtering components, especially the output capaci-
tor. Use high-ESR aluminum electrolytic capacitors for
cost-sensitive applications. Use low-ESR tantalum or
ceramic capacitors at the output for size sensitive
applications. The high switching frequency of the
MAX15026 allows the use of ceramic capacitors at the
output. Choose all passive power components to meet
the output ripple, component size, and component cost
Maxim Integrated
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX15026CETD+ | 功能描述:DC/DC 开关控制器 4.5-28V Synchronous Buck 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 |
| MAX15026CETD+G1D | 制造商:Maxim Integrated Products 功能描述:LOW-COST, SMALL, 4.5V TO 28V WIDE OPERATING RANGE, DC-DC SYN - Rail/Tube |
| MAX15026CETD+T | 功能描述:DC/DC 开关控制器 4.5-28V Synchronous Buck 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 |
| MAX15026CETD+TG1D | 制造商:Maxim Integrated Products 功能描述:LOW-COST, SMALL, 4.5V TO 28V WIDE OPERATING RANGE, DC-DC SYN - Tape and Reel |
| MAX15026CETD+TW | 制造商:Maxim Integrated Products 功能描述:LOW-COST SMALL 4.5V TO 28V WIDE OPERATING RANGE DC-DC CONT - Tape and Reel |
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