参数资料
型号: MAX618EEE+T
厂商: Maxim Integrated Products
文件页数: 10/14页
文件大小: 0K
描述: IC REG BOOST ADJ 0.5A 16QSOP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 2,500
类型: 升压(升压)
输出类型: 可调式
输出数: 1
输出电压: 可调至 28V
输入电压: 3 V ~ 28 V
PWM 型: 混合物
频率 - 开关: 250kHz
电流 - 输出: 500mA
同步整流器:
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
28V, PWM, Step-Up DC-DC Converter
Maximum Output Current
The MAX618’s 2.2A LX current limit determines the
output power that can be supplied for most applica-
tions. In some cases, particularly when the input volt-
C COMP =
C COMP (Table 5) ? C OUT
C OUT ( Table 4 )
age is low, output power is sometimes restricted by
package dissipation limits. The MAX618 is protected
by a thermal shutdown circuit that turns off the switch
when the die temperature exceeds +150°C. When the
device cools by 10°C, the switch is enabled again.
Table 3 details output current with a variety of input and
Pole Compensation Capacitor
The pole capacitor (C P ) cancels the unwanted zero
introduced by C OUT ’s ESR, and thereby ensures stabil-
ity in PWM operation. The exact value of the pole
capacitor is not critical, but it should be near the value
calculated by the following equation:
output voltages. Each listing in Table 3 is either the limit
set by an LX current limit or by package dissipation at
+85°C ambient, whichever is lower. The values in Table
3 assume a 40m Ω inductor resistance.
C P =
R ESR ? C OUT (R1 + R2)
R1 ? R2
Capacitor Selection
Input Capacitors
The input bypass capacitor, C IND , reduces the input
ripple created by the boost configuration. High-imped-
ance sources require high C IND values. However, 68μF
is generally adequate for input currents up to 2A. Low
ESR capacitors are recommended because they will
decrease the ripple created on the input and improve
efficiency. Capacitors with ESR below 0.3 Ω are gener-
ally appropriate.
In addition to the input bypass capacitor, bypass IN
with a 1μF ceramic capacitor placed as close to the IN
and GND pins as possible. Bypass VL with a 4.7μF
ceramic capacitor placed as close to the VL and GND
pins as possible.
Output Capacitor
Use Table 4 to find the minimum output capacitance
necessary to ensure stable operation. In addition,
choose an output capacitor with low ESR to reduce the
output ripple. The dominant component of output ripple
where R ESR is C OUT ’s ESR.
Layout Considerations
Proper PC board layout is essential due to high current
levels and fast switching waveforms that radiate noise.
Use the MAX618 evaluation kit or equivalent PC layout
to perform initial prototyping. Breadboards, wire-wrap,
and proto-boards are not recommended when proto-
typing switching regulators.
It is important to connect the GND pin, the input
bypass capacitor ground lead, and the output filter
capacitor ground lead to a single point to minimize
ground noise and improve regulation. Also, minimize
lead lengths to reduce stray capacitance, trace resis-
tance, and radiated noise, with preference given to the
feedback circuit, the ground circuit, and LX. Place the
feedback resistors as close to the FB pin as possible.
Place a 1μF input bypass capacitor as close as possi-
ble to IN and GND.
Refer to the MAX618 evaluation kit for an example of
proper board layout.
is the product of the peak-to-peak inductor ripple cur-
rent and the ESR of the output capacitor. ESR below
50m Ω generates acceptable levels of output ripple for
PROCESS: BiCMOS
Chip Information
most applications.
Integrator Capacitor
The compensation capacitor (C COMP ) sets the domi-
nant pole in the MAX618’s transfer function. The proper
compensation capacitance depends upon output
capacitance. Table 5 shows the capacitance value
Package Information
For the latest package outline information and land patterns,
go to www.maxim-ic.com/packages . Note that a “+”, “#”, or
“-” in the package code indicates RoHS status only. Package
drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
needed for the output capacitances specified in Table
4. However, if a different output capacitor is used (e.g.,
a standard value), then recalculate the value of capaci-
PACKAGE TYPE
16 QSOP
PACKAGE CODE
EF16+8F
DOCUMENT NO.
tance needed for the integrator capacitor with the fol-
lowing formula:
10
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MAX6190A 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:Precision, Micropower, Low-Dropout Voltage References
MAX6190AESA 功能描述:基准电压& 基准电流 Precision uPower Voltage Ref RoHS:否 制造商:STMicroelectronics 产品:Voltage References 拓扑结构:Shunt References 参考类型:Programmable 输出电压:1.24 V to 18 V 初始准确度:0.25 % 平均温度系数(典型值):100 PPM / C 串联 VREF - 输入电压(最大值): 串联 VREF - 输入电压(最小值): 分流电流(最大值):60 mA 最大工作温度:+ 125 C 封装 / 箱体:SOT-23-3L 封装:Reel