参数资料
型号: MAX5033DASA+T
厂商: Maxim Integrated Products
文件页数: 9/17页
文件大小: 0K
描述: IC REG BUCK ADJ 0.5A 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: 500mA
同步整流器:
工作温度: -40°C ~ 125°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
MAX5033
500mA, 76V, High-Efficiency, MAXPower
Step-Down DC-DC Converter
Detailed Description
The MAX5033 step-down DC-DC converter operates
from a 7.5V to 76V input voltage range. A unique volt-
age-mode control scheme with voltage feed-forward
and an internal switching DMOS FET provides high effi-
ciency over a wide input voltage range. This pulse-
width modulated converter operates at a fixed 125kHz
switching frequency. The device also features automat-
ic pulse-skipping mode to provide low quiescent cur-
rent and high efficiency at light loads. Under no load,
the MAX5033 consumes only 270μA, and in shutdown
mode, consumes only 10μA. The MAX5033 also fea-
tures undervoltage lockout, hiccup-mode output short-
circuit protection, and thermal shutdown.
Shutdown Mode
Drive ON/ OFF to ground to shut down the MAX5033.
Shutdown forces the internal power MOSFET off, turns
off all internal circuitry, and reduces the V IN supply cur-
rent to 10μA (typ). The ON/ OFF rising threshold is
1.69V (typ). Before any operation begins, the voltage at
ON/ OFF must exceed 1.69V (typ). The ON/ OFF input
has 100mV hysteresis.
Undervoltage Lockout (UVLO)
Use the ON/ OFF function to program the UVLO thresh-
old at the input. Connect a resistive voltage-divider
from V IN to GND with the center node to ON/ OFF as
shown in Figure 1. Calculate the threshold value by
using the following formula:
On startup, an internal low-side switch connects LX to
ground and charges the BST capacitor to VD. Once the
BST capacitor is charged, the internal low-side switch
is turned off and the BST capacitor voltage provides
the necessary enhancement voltage to turn on the
high-side switch.
Thermal-Overload Protection
The MAX5033 features integrated thermal-overload
protection. Thermal-overload protection limits total
power dissipation in the device, and protects the
device in the event of a fault condition. When the die
temperature exceeds +160°C, an internal thermal sen-
sor signals the shutdown logic, turning off the internal
power MOSFET and allowing the IC to cool. The ther-
mal sensor turns the internal power MOSFET back on
after the IC’s die temperature cools down to +140°C,
resulting in a pulsed output under continuous thermal-
overload conditions.
Applications Information
Setting the Output Voltage
The MAX5033A/B/C have preset output voltages of 3.3V,
5.0V, and 12V, respectively. Connect FB to the preset
output voltage (see the Typical Operating Circuit).
The MAX5033D offers an adjustable output voltage. Set
the output voltage with a resistive voltage-divider con-
nected from the circuit’s output to ground (Figure 1).
Connect the center node of the divider to FB. Choose
R4 less than 15k ? , then calculate R3 as follows:
V UVLO ( TH ) = ? 1 +
?
?
R1 ?
R 2 ? ?
× 1 . 85 V
R 3 =
(V OUT ? 1 . 22)
1 . 22
× R 4
The minimum recommended V UVLO(TH) is 6.5V, 7.5V,
and 13V for the output voltages of 3.3V, 5V, and 12V,
respectively. The recommended value for R2 is less
than 1M ? .
If the external UVLO threshold-setting divider is not used,
an internal undervoltage-lockout feature monitors the
supply voltage at V IN and allows operation to start when
V IN rises above 5.2V (typ). This feature can be used only
when V IN rise time is faster than 2ms. For slower V IN rise
time, use the resistive divider at ON/ OFF .
V IN
7.5V TO 76V
R1
R2
47 μ F
V IN
ON/OFF
MAX5033D
LX
BST
0.1 μ F
220 μ H
D1
50SQ100
R3
41.2k ?
V OUT
5V, 0.5A
C OUT
33 μ F
Boost High-Side Gate Drive (BST)
Connect a flying bootstrap capacitor between LX and
FB
BST to provide the gate-drive voltage to the high-side
n-channel DMOS switch. The capacitor is alternately
SGND
GND
VD
0.1 μ F
R4
13.3k ?
charged from the internally regulated output-voltage VD
and placed across the high-side DMOS driver. Use a
0.1μF, 16V ceramic capacitor located as close to the
device as possible.
Maxim Integrated
Figure 1. Adjustable Output Voltage
9
相关PDF资料
PDF描述
USV1A330MFD CAP ALUM 33UF 10V 20% RADIAL
RBM36DCBD CONN EDGECARD 72POS R/A .156 SLD
USV1A220MFD CAP ALUM 22UF 10V 20% RADIAL
MAX5035DUSA+T IC REG BUCK ADJ 1A 8SOIC
USV0J470MFD CAP ALUM 47UF 6.3V 20% RADIAL
相关代理商/技术参数
参数描述
MAX5033DEPA+ 制造商:Maxim Integrated Products 功能描述:- Rail/Tube
MAX5033DESA+ 制造商:Maxim Integrated Products 功能描述:- Rail/Tube
MAX5033DUPA 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
MAX5033DUPA+ 功能描述:直流/直流开关转换器 500mA 76V MAXPower Step-Down 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
MAX5033DUSA 功能描述:直流/直流开关转换器 500mA 76V MAXPower Step-Down 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