- 您现在的位置：买卖IC网 > PDF目录13476 > MAX667CPA+ (Maxim Integrated Products)IC REG LDO 5V/ADJ .25A 8-DIP PDF资料下载
参数资料
| 型号： | MAX667CPA+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 5/9页 |
| 文件大小： | 0K |
| 描述： | IC REG LDO 5V/ADJ .25A 8-DIP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 50 |
| 稳压器拓扑结构： | 正，固定式或可调式 |
| 输出电压： | 5V，1.3 V ~ 16 V |
| 输入电压： | 3.5 V ~ 16.5 V |
| 电压 - 压降（标准）： | 0.15V @ 250mA |
| 稳压器数量： | 1 |
| 电流 - 输出： | 250mA（最小） |
| 工作温度： | 0°C ~ 70°C |
| 安装类型： | 通孔 |
| 封装/外壳： | 8-DIP（0.300"，7.62mm） |
| 供应商设备封装： | 8-PDIP |
| 包装： | 管件 |
| 产品目录页面： | 1409 (CN2011-ZH PDF) |
+5V/Programmable Low-Dropout
Voltage Regulator
Output-Voltage Selection
If SET is connected to a resistive voltage divider (Figure
3), the output voltage is set by the equation:
V OUT = V SET x (R1 + R2) / R1,
where V SET = 1.22V
To simplify resistor selection:
R2 = R1 x (V OUT / V SET - 1)
Since the input bias current at SET has a maximum
value of 10nA, relatively large values can be used for
R1 and R2 with no loss of accuracy. 1M Ω is a typical
value for R1. The V SET tolerance is less than ±25mV.
This allows the output to be preset without trim pots,
using only fixed resistors in most cases. However, when
resistor values greater than 1M Ω are used, pay special
attention to printed circuit board leakage that can intro-
duce error at the SET input.
Shutdown (Standby) Mode
SHDN puts the device into standby mode to conserve
power. When this pin is held low, the IC operates nor-
mally. If it is driven above 1.5V, the chip shuts down.
Quiescent current of the MAX667 is then reduced to
less than 1μA, and OUT turns off.
Note that the voltage for SHDN must never be more
than 0.3V higher than V IN .
Low-Battery Function
The MAX667 contains circuitry for low-battery detec-
tion. If the voltage at LBI falls below the regulator’s
internal reference (1.22V), LBO, an open-drain output,
sinks current to GND. The threshold can be set to any
level above the reference voltage by connecting a
resistive divider to LBI based on the equation:
R3 = R4 x (V BATT / V LBI - 1)
where V BATT is the desired threshold of the low-battery
detector, and R3 and R4 are the LBI input divider
resistors.
Since LBI input current is no more than 10nA, high val-
ues for R3 and R4 minimize loading. If V OUT is 5V, a
5.5V low-battery threshold can be set using 8.2M Ω for
R3 and 2.4M Ω for R4. When resistor values greater
than 1M Ω are used, pay special attention to PC board
leakage that can introduce error at the LBI input.
Dropout Detector
The minimum input-output differential, or dropout volt-
age, determines the regulator’s lowest usable input
voltage. In battery-operated systems, this determines
the useful end-of-life battery voltage. The MAX667 fea-
tures very low dropout voltage (see Electrical
Characteristics ). In addition, the MAX667 has a dropout
detector output, DD, that changes as the dropout volt-
age approaches its limit. DD is an open collector of a
PNP transistor. The dropout voltage and the dropout
detector both depend on the output current and tem-
perature. When the input voltage is more than 300mV
above the output voltage, the dropout detector will not
conduct. As the differential decreases below 300mV,
the DD source current increases abruptly. This current
signals a warning that regulation is about to be lost.
Connecting a resistor (typically 100k Ω ) from DD to
ground develops a voltage that can be monitored by
analog circuits or changed to digital levels by a com-
parator. LBI may be used for this purpose.
__________Applications Information
Output Capacitor
As with all PNP output regulators, an output capacitor
(C1, Figure 2) is required to maintain stability. 10μF is
recommended. To ensure stability, the output-capacitor
ESR must be sufficiently high. Figure 4 shows the mini-
mum required output-capacitor ESR for a given temper-
ature. Alternatively, a resistor may be added in series
with the output capacitor (Figure 5); the sum of the out-
5
4
3
2
1
When the voltage at LBI is below the internal threshold,
LBO sinks current to GND. A pull-up resistor of 10k Ω or
0
-60 -40 -20
0
20
40 60
80 100 120
more connected to OUT can be used with this pin when
driving CMOS circuits. Any pull-up resistor connected
to LBO should not be returned to a voltage source
greater than V OUT . When LBI is above the threshold or
the MAX667 is in SHDN mode, the LBO output is off.
TEMPERATURE ( ?C )
Figure 4. Minimum Required Output-Capacitor ESR vs.
Temperature
_______________________________________________________________________________________
5
相关PDF资料 |
PDF描述 |
|---|---|
| ESC44DRXS | CONN EDGECARD 88POS DIP .100 SLD |
| ABB20DHLT | CONN EDGECARD 40POS .050 DIP SLD |
| MAX6772TASD4+T | IC REG LINEAR 3.3V/ADJ 8-TDFN |
| ACB06DHAS | CONN EDGECARD 12POS R/A .050 DIP |
| EMC26DRXS | CONN EDGECARD 52POS DIP .100 SLD |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX667CPA+ | 功能描述:低压差稳压器 - LDO 5V Programmable Voltage Regulator RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压（最大值）:307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20 |
| MAX667CSA | 功能描述:低压差稳压器 - LDO 5V Programmable Voltage Regulator RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压（最大值）:307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20 |
| MAX667CSA+ | 功能描述:低压差稳压器 - LDO 5V Programmable Voltage Regulator RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压（最大值）:307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20 |
| MAX667CSA+T | 功能描述:低压差稳压器 - LDO 5V Programmable Voltage Regulator RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压（最大值）:307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20 |
| MAX667CSA-T | 功能描述:低压差稳压器 - LDO 5V Programmable Voltage Regulator RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压（最大值）:307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20 |
发布紧急采购，3分钟左右您将得到回复。