参数资料
型号: MAX5035DUSA+T
厂商: Maxim Integrated Products
文件页数: 11/17页
文件大小: 0K
描述: IC REG BUCK ADJ 1A 8SOIC
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: 可调式
输出数: 1
输出电压: 1.25 V ~ 13.2 V
输入电压: 7.5 V ~ 76 V
PWM 型: 电压模式
频率 - 开关: 125kHz
电流 - 输出: 1A
同步整流器:
工作温度: 0°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 8-SOIC(0.154",3.90mm 宽)
包装: 带卷 (TR)
供应商设备封装: 8-SOIC
MAX5035
1A, 76V, High-Efficiency MAXPower
Step-Down DC-DC Converter
The MAX5035 features internal compensation for opti-
mum closed-loop bandwidth and phase margin. With
the preset compensation, it is strongly advised to sense
the output immediately after the primary LC.
Inductor Selection
The choice of an inductor is guided by the voltage dif-
ference between V IN and V OUT , the required output
current, and the operating frequency of the circuit. Use
an inductor with a minimum value given by:
drop (V FB ) less than 0.45V at +25 ° C and maximum load
current to avoid forward biasing of the internal body
diode (LX to ground). Internal body diode conduction
may cause excessive junction temperature rise and
thermal shutdown. Use Table 1 to choose the proper
rectifier at different input voltages and output current.
Input Bypass Capacitor
The discontinuous input-current waveform of the buck
converter causes large ripple currents in the input
L =
( V IN ? V OUT ) × D
0 . 3 × I OUTMAX × f SW
capacitor. The switching frequency, peak inductor cur-
rent, and the allowable peak-to-peak voltage ripple that
reflects back to the source dictate the capacitance
requirement. The MAX5035 high switching frequency
where:
D =
V OUT
V IN
allows the use of smaller-value input capacitors.
The input ripple is comprised of ? V Q (caused by the
capacitor discharge) and ? V ESR (caused by the ESR of
the capacitor). Use low-ESR aluminum electrolytic
capacitors with high ripple-current capability at the input.
I OUTMAX is the maximum output current required, and
f SW is the operating frequency of 125kHz. Use an induc-
tor with a maximum saturation current rating equal to at
least the peak switch current limit (I LIM ). Use inductors
Assuming that the contribution from the ESR and capaci-
tor discharge is equal to 90% and 10%, respectively, cal-
culate the input capacitance and the ESR required for a
specified ripple using the following equations:
ESR IN =
? ? I OUT + 2 ? ?
C IN = OUT
? I L =
with low DC resistance for higher efficiency.
Selecting a Rectifier
The MAX5035 requires an external Schottky rectifier as
a freewheeling diode. Connect this rectifier close to the
device using short leads and short PC board traces.
Choose a rectifier with a continuous current rating
greater than the highest expected output current. Use a
rectifier with a voltage rating greater than the maximum
expected input voltage, V IN . Use a low forward-voltage
Schottky rectifier for proper operation and high efficien-
cy. Avoid higher than necessary reverse-voltage
where :
? V ESR
? ? I L ?
I × D (1 ? D)
? V Q × f SW
(V IN ? V OUT ) × V OUT
V IN × f SW × L
,
Schottky rectifiers that have higher forward-voltage
drops. Use a Schottky rectifier with forward-voltage
Table 1. Diode Selection
D =
V OUT
V IN
V IN (V)
7.5 to 36
7.5 to 56
7.5 to 76
DIODE PART NUMBER
15MQ040N
B240A
B240
MBRS240, MBRS1540
30BQ060
B360A
CMSH3-60
MBRD360, MBR3060
50SQ100, 50SQ80
MBRM5100
MANUFACTURER
IR
Diodes, Inc.
Central Semiconductor
ON Semiconductor
IR
Diodes, Inc.
Central Semiconductor
ON Semiconductor
IR
Diodes, Inc.
I OUT is the maximum output current of the converter
and f SW is the oscillator switching frequency (125kHz).
For example, at V IN = 48V, V OUT = 3.3V, the ESR and
input capacitance are calculated for the input peak-to-
peak ripple of 100mV or less yielding an ESR and
capacitance value of 80m ? and 51μF, respectively.
Low-ESR, ceramic, multilayer chip capacitors are recom-
mended for size-optimized application. For ceramic
capacitors, assume the contribution from ESR and capaci-
tor discharge is equal to 10% and 90%, respectively.
The input capacitor must handle the RMS ripple current
without significant rise in temperature. The maximum
capacitor RMS current occurs at about 50% duty cycle.
Maxim Integrated
11
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MAX5035EASA/V+ 功能描述:直流/直流开关转换器 MA1A 76V High-Efficiency MAXPower Step-Down DC-DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX5035EASA/V+T 功能描述:直流/直流开关转换器 NULL RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX5035EASA+ 功能描述:直流/直流开关转换器 1A 76V High-Efficiency MAXPower Step-Down DC-DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX5035EASA+T 功能描述:直流/直流开关转换器 1A 76V High-Efficiency MAXPower Step-Down DC-DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX5035EUPA+ 功能描述:直流/直流开关转换器 RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT