参数资料
| 型号： | MAX8758ETG+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 12/20页 |
| 文件大小： | 0K |
| 描述： | IC REG STEP UP 24-TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 应用： | 转换器，TFT，LCD |
| 输入电压： | 1.8 V ~ 5.5 V |
| 输出数： | 1 |
| 输出电压： | 5V |
| 工作温度： | 0°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 24-WFQFN 裸露焊盘 |
| 供应商设备封装： | 24-TQFN-EP（4x4） |
| 包装： | 带卷 (TR) |
Step-Up Regulator with Switch Control
and Operational Amplifier for TFT LCD
Table 2. Component Suppliers
SUPPLIER
Fairchild Semiconductor
Sumida
TDK
Toshiba
PHONE
408-822-2000
847-545-6700
847-803-6100
949-455-2000
FAX
408-822-2102
847-545-6720
847-390-4405
949-859-3963
WEBSITE
www.fairchildsemi.com
www.sumida.com
www.component.tdk.com
www.toshiba.com/taec
The internal n-channel power MOSFET reduces the
number of external components. The supply rail of the
internal gate driver is bootstrapped to the internal linear
regulator output to improve the efficiency at low-input
voltages. The external-capacitor, soft-start function
effectively controls inrush currents. The output voltage
can be set from V IN to 13V with an external resistive
voltage-divider.
CLOCK
LOGIC AND
DRIVER
ILIM
COMPARATOR
LX
PGND
PWM Control Block
Figure 3 is the block diagram of the step-up regulator.
The regulator controls the output voltage and the power
SLOPE COMP
SOFT-
START
I LIMIT
SS
delivered to the output by modulating the duty cycle (D)
of the internal power MOSFET in each switching cycle.
The duty cycle of the MOSFET is approximated by:
OSCILLATOR
PWM
COMPARATOR
∑
CURRENT
SENSE
D ≈
V OUT ? V IN
V OUT
FAULT
COMPARATOR
TO FAULT LOGIC
1.0V
ERROR AMP
FB
where V OUT is the output voltage of the step-up regulator.
On the rising edge of the internal oscillator clock, the
controller sets a flip-flop, turning on the n-channel
MOSFET and applying the input voltage across the
inductor. The current through the inductor ramps up lin-
early, storing energy in its magnetic field. A transcon-
ductance error amplifier compares the FB voltage with
a 1.24V (typ) reference voltage. The error amplifier
changes the COMP voltage by charging or discharging
the COMP capacitor. The COMP voltage is compared
with a ramp, which is the sum of the current-sense sig-
nal and a slope compensation signal. Once the ramp
signal exceeds the COMP voltage, the controller resets
the flip-flop and turns off the MOSFET. Since the induc-
tor current is continuous, a transverse potential devel-
ops across the inductor that turns on the Schottky
diode (D1 in Figure 1). The voltage across the inductor
then becomes the difference between the output volt-
age and the input voltage. This discharge condition
forces the current through the inductor to ramp down,
transferring the energy stored in the magnetic field to
the output capacitor and the load. The MOSFET
remains off for the rest of the clock cycle.
1.24V
COMP
FREQ
Figure 3. Step-Up Regulator Block Diagram
Bootstrapping and Soft-Start
The MAX8758 features bootstrapping operation. In nor-
mal operation, the internal linear regulator supplies
power to the internal circuitry. The input of the linear
regulator (OUT) should be directly connected to the
output of the step-up regulator. The step-up regulator is
enabled when the input voltage at OUT is above 1.75V,
SHDN is high, and the fault latch is not set.
After being enabled, the regulator starts open-loop
switching to generate the supply voltage for the linear
regulator with a controlled duty cycle. The internal ref-
erence block turns on when the LDO voltage exceeds
2.7V (typ). When the reference voltage reaches regula-
tion, the PWM controller and the current-limit circuit are
enabled and the step-up regulator enters soft-start.
12
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX8758ETJ | 功能描述:LCD 驱动器 Step-Up Regulator RoHS:否 制造商:Maxim Integrated 数位数量:4.5 片段数量:30 最大时钟频率:19 KHz 工作电源电压:3 V to 3.6 V 最大工作温度:+ 85 C 最小工作温度:- 20 C 封装 / 箱体:PDIP-40 封装:Tube |
| MAX8758EVKIT | 功能描述:电源管理IC开发工具 MAX8758 Eval Kit RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
| MAX8759AETI+ | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX8759ETI+ | 功能描述:显示驱动器和控制器 SMBus CCFL Backlight Controller RoHS:否 制造商:Panasonic Electronic Components 工作电源电压:2.7 V to 5.5 V 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:QFN-44 封装:Reel |
| MAX8759ETI+T | 功能描述:显示驱动器和控制器 SMBus CCFL Backlight Controller RoHS:否 制造商:Panasonic Electronic Components 工作电源电压:2.7 V to 5.5 V 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:QFN-44 封装:Reel |
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