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参数资料
| 型号： | MAX1729EUB |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 7/12页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK BST ADJ 2.5MA 10UMAX |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 50 |
| 类型： | 降压（降压），升压（升压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 2.5 V ~ 16 V |
| 输入电压： | 2.7 V ~ 5.5 V |
| 电流 - 输出： | 2.5mA |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 10-TFSOP，10-MSOP（0.118"，3.00mm 宽） |
| 包装： | 管件 |
| 供应商设备封装： | 10-µMAX |
ECB and LCD Display Bias Supply with Accurate
Output Voltage and Temperature Compensation
equal to the reference voltage at room temperature. TC
is capable of sinking or sourcing 50μA. This output is
IN
LX
used to compensate for ECB color or LCD contrast
TC
TEMPERATURE
SENSOR
BOOST
CONVERTER
PS
variations caused by changes in temperature. It may
be read with an ADC and used to modify an external
PWM control signal or, in external feedback mode,
summed directly into the feedback-resistor network.
REF
FB
VOLTAGE
REFERENCE
MAX1729
LDO
LINEAR
REGULATOR
FEEDBACK
CONTROL
OUT
Control Signal
An externally generated PWM control signal on CTLIN
controls V OUT in internal feedback mode and influ-
ences V OUT in external feedback mode. In either mode,
if CTLIN is held low for longer than 1.24ms, the
MAX1729 enters shutdown mode, decreasing the sup-
ply current below 2μA. Shutdown mode limits the mini-
122mV
mum duty cycle and frequency that may be used to
keep the device active. CTLIN frequencies between
2kHz and 12kHz are recommended.
Internal Feedback Mode
SHUTDOWN
CONTROL
V REF
In internal feedback mode, the signal at CTLIN is inverse-
ly buffered, level-shifted, and output at COMP through a
resistor. Internal resistance (33k ? typical) and C6 then fil-
CTLIN
GND
ter the signal before it is used by the internal feedback
network to set V OUT . If temperature compensation is
used, the temperature sensor output voltage is read by
an ADC and used to adjust the duty cycle of the PWM
GND
COMP
control signal. See the Designing for Internal Feedback
Mode section for more information.
NOTE: SWITCH STATES SHOWN FOR INTERNAL FEEDBACK MODE.
Figure 1. Internal Block Diagram
inductor current to ramp down and V PS to increase. If, at
the end of t OFF , V PS - V OUT is still too low, then another
t ON is initiated immediately. Otherwise, the boost con-
verter remains idle in a low-quiescent-current state until
V PS - V OUT drops again and the error comparator initi-
ates another cycle.
Linear Regulator
The PNP low-dropout linear regulator of the MAX1729
regulates the boost-converter output to the desired out-
put voltage. The boost converter’s regulation circuitry
holds the linear regulator’s input voltage (V PS ) approxi-
mately 0.6V above the output voltage to keep the regu-
lator out of dropout, thereby enhancing ripple rejection.
The linear regulator incorporates short-circuit protec-
tion, which limits the output current to approximately
6mA.
Temperature Sensor Output
The MAX1729 generates a temperature sensor voltage
(V TC ) that varies at 16.5mV/°C (typ) and is nominally
External Feedback Mode
In external feedback mode, the output voltage of the
MAX1729 is controlled by the duty cycle of the PWM
control signal and an external resistor network, as
shown in Figure 3. In this mode, the signal at CTLIN is
inverted, level-shifted, and presented directly to COMP.
R3, R4, and C6 filter the signal, before it is summed into
the feedback node.
Design Procedure
Designing for Internal Feedback Mode
For a 3kHz PWM control signal use a 1μF low-leakage
ceramic capacitor for C6. For applications requiring a
higher-frequency PWM control signal, reduce the value
of C6 to between 1μF and 0.22μF for frequencies
between 3kHz and 12kHz. Higher C6 values reduce
output ripple. In Figure 2, V OUT is governed by the fol-
lowing equation:
V OUT = V OUT(MIN) + Duty Cycle ? Gain
where V OUT(MIN) is 2.45V and Gain is nominally
13.95V/100%, as listed in the Electrical Characteristics.
_______________________________________________________________________________________
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1729EUB-T | 功能描述:直流/直流开关转换器 ECB & LCD Display Bias Supply 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 |
| MAX172ACNG | 功能描述:模数转换器 - ADC Integrated Circuits (ICs) RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
| MAX172ACNG+ | 功能描述:模数转换器 - ADC 12-Bit 100ksps 5.25V- Precision ADC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
| MAX172ACWG | 功能描述:模数转换器 - ADC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
| MAX172ACWG+ | 功能描述:模数转换器 - ADC 12-Bit 100ksps 5.25V- Precision ADC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
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