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参数资料
| 型号： | MAX1626ESA |
| 厂商： | MAXIM INTEGRATED PRODUCTS INC |
| 元件分类： | 稳压器 |
| 英文描述： | 5V/3.3V or Adjustable, 100% Duty-Cycle, High-Efficiency, Step-Down DC-DC Controllers |
| 中文描述： | 0.05 A SWITCHING CONTROLLER, 300 kHz SWITCHING FREQ-MAX, PDSO8 |
| 封装： | 0.150 INCH, MS-012A, SOIC-8 |
| 文件页数： | 8/16页 |
| 文件大小： | 185K |
| 代理商： | MAX1626ESA |
M
EX T Drive V oltage Range
EXT swings from V+ to GND and provides the gate
drive for an external P-channel power MOSFET. A high-
er supply voltage increases the gate drive to the
MOSFET and reduces on-resistance (R
DS(ON)
). See
External Switching Transistorsection.
Quiesc ent Current
The device’s typical quiescent current is 70μA.
However, actual applications draw additional current to
supply MOSFET switching currents, OUT pin current, or
external feedback resistors (if used), and both the diode
and capacitor leakage currents. For example, in the cir-
cuit of Figure 1, with V+ at 7V and V
OUT
at 5V, typical
no-load supply current for the entire circuit is 84μA.
When designing a circuit for high-temperature opera-
tion, select a Schottky diode with low reverse leakage.
S hutdown Mode
When SHDN is high, the device enters shutdown mode.
In this mode, the feedback and control circuit, reference,
and internal biasing circuitry are turned off. EXT goes
high, turning off the external MOSFET. The shutdown
supply current drops to less than 1μA. SHDN is a logic-
level input. Connect SHDN to GND for normal operation.
Referenc e
The 1.3V reference is suitable for driving external loads,
such as an analog-to-digital converter. It has a guaran-
teed 10mV maximum load regulation while sourcing load
currents up to 100μA. The reference is turned off during
shutdown. Bypass the reference with 0.1μF for normal
operation. Place the bypass capacitor within 0.2 inches
(5mm) of REF, with a direct trace to GND (Figure 7).
S oft-S tart
Soft-start reduces stress and transient voltage slumps
on the power source. When the output voltage is near
ground, the minimum off-time is lengthened to limit peak
switching current. This compensates for reduced nega-
tive inductor current slope due to low output voltages.
________________Design Information
S etting the Output V oltage
The MAX1626’s output voltage can be selected to 3.3V
or 5V under logic control by using the
3
/5 pin. The
3
/5
pin requires less than 0.5V to ensure a 3.3V output, or
more than (V+ - 0.5)V to guarantee a 5V output. The
voltage sense pin (OUT) must be connected to the out-
put for the MAX1626.
The MAX1627’s output voltage is set using two resis-
tors, R2 and R3 (Figure 5), which form a voltage divider
between the output and GND. R2 is given by:
where V
REF
= 1.3V. Since the input bias current at FB
has a maximum value of 50nA, large values (10k
to
200k
) can be used for R3 with no significant accuracy
loss. For 1% error, the current through R2 should be at
R2 = R3 x
V
V
OUT
REF
1
5V /3.3V or Adjustable, 100% Duty-Cyc le,
High-Effic ienc y, S tep-Down DC-DC Controllers
8
_______________________________________________________________________________________
10
μ
s/div
CIRCUIT OF FIGURE 1, V+ = 8V, V
OUT
= 5V, LOAD = 100mA
A: MOSFET DRAIN, 5V/div
B: OUT, 50mV/div, 5V DC OFFSET
C: INDUCTOR CURRENT, 1A/div
B
0A
C
A
Figure 3. Discontinuous-Conduction Mode, Light-Load-Current
Waveform
10
μ
s/div
CIRCUIT OF FIGURE 1, V+ = 8V, V
OUT
= 5V, LOAD = 1.5A
A: MOSFET DRAIN, 5V/div
B: OUT, 50mV/div, 5V DC OFFSET
C: INDUCTOR CURRENT, 1A/div
B
0A
C
A
Figure 4. Continuous-Conduction Mode, Heavy-Load-Current
Waveform
相关PDF资料 |
PDF描述 |
|---|---|
| MAX1627ESA | 5V/3.3V or Adjustable, 100% Duty-Cycle, High-Efficiency, Step-Down DC-DC Controllers |
| MAX1626-MAX1627 | 5V/3.3V or Adjustable, 100% Duty-Cycle, High-Efficiency, Step-Down DC-DC Controllers |
| MAX1630 | Multi-Output, Low-Noise Power-Supply Controllers for Notebook Computers |
| MAX1631 | Multi-Output, Low-Noise Power-Supply Controllers for Notebook Computers |
| MAX1631CAI | Multi-Output, Low-Noise Power-Supply Controllers for Notebook Computers |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1626ESA+ | 功能描述:DC/DC 开关控制器 5/3.3V or Adjustable 100% Duty Cycle RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| MAX1626ESA+T | 功能描述:DC/DC 开关控制器 5/3.3V or Adjustable 100% Duty Cycle RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| MAX1626ESA-T | 功能描述:DC/DC 开关控制器 5/3.3V or Adjustable 100% Duty Cycle RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| MAX1626EVKIT | 功能描述:DC/DC 开关控制器 3V/3.3V 100% Duty-Cycle High-Efficiency Step-Down DC-DC Controller RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| MAX1626EVKIT-SO | 功能描述:DC/DC 开关控制器 Evaluation Kit for the MAX1626 MAX1627 RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
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