参数资料
| 型号： | NCV8612BMNR2G |
| 厂商： | ON Semiconductor |
| 文件页数： | 10/26页 |
| 文件大小： | 0K |
| 描述： | IC REG LDO 5V/3.3V/ADJ 20DFN |
| 标准包装： | 2,500 |
| 稳压器拓扑结构： | 正，固定式和可调式 |
| 输出电压： | 5V，3.3V，可调式 |
| 输入电压： | 7 V ~ 18 V |
| 稳压器数量： | 3 |
| 电流 - 输出： | 120mA，80mA，400mA |
| 电流 - 限制（最小）： | 180mA，120mA，500mA |
| 工作温度： | -40°C ~ 150°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 20-VFDFN 裸露焊盘 |
| 供应商设备封装： | 20-QFN（6x5） |
| 包装： | 带卷 (TR) |
NCV8612B
CIRCUIT DESCRIPTION
Auto Switchover Circuitry
The auto switchover circuit is designed to insure
continuous operation of the device, automatically switching
the input voltage from the ASO_RAIL input, to the VIN ? B
input, to the VIN ? H input depending on conditions. The
primary input voltage pin is ASO_RAIL, which is driven
from the 8 V supply. When this voltage is present it will drive
the output voltages. Regardless of whether the 8 V supply is
available, the reference and core functions of the device will
be driven by the higher of VIN ? B and VIN ? H. The
switchover control circuitry will be powered solely by the
8 V supply, via VIN ? A.
When the 8 V supply is not present, the gates of the 2
P ? FET switches will be pulled to ground, turning the
switches on. In this condition, the VIN ? B and VIN ? H
voltages will be diode or ’ed, with the higher voltage
powering the chip. The VIN ? H voltage will be one diode
lower than the VIN ? B voltage, thereby forcing the VIN ? B
voltage to be dominant supply.
In the event that both the 8 V supply and the VIN ? B supply
are not present, the VIN ? H supply will be powering the
device. The VIN ? H supply is then fed from a recommended
1000 m F cap. The duration of VIN ? H supply is dependent on
output current. It is intended as protection against temporary
loss of battery conditions.
In the event of a double battery, or prolonged high voltage
condition on the battery line, a bleed transistor has been
included on the VIN ? H line. With the large hold ? up cap on
VIN ? H, the voltage on that pin has the potential to remain
in an elevated position for an extended period of time. The
main result of this condition would be an
Overvoltage Shutdown of the device. In order to avoid this
condition, a transistor that is connected to the
Overvoltage Shutdown signal is tied to the VIN ? H line. This
transistor will become active in a high voltage event,
allowing the hold ? up cap to discharge the excess voltage in
a timely manner.
In the Block Diagram, Figure 1, C ASO_RAIL is listed as a
1 m F capacitor. It is required for proper operation of the
device that C ASO_RAIL is no larger than 1 m F.
During a switchover event, a timer in the output stages
prepares the regulator in anticipation of change in input
voltage. The event results in a hitch in the output waveforms,
I OUT = 120 mA
C OUT = 47 m F
Figure 3. V OUTX Response to ASO Switchover Event
VIN ? B/VIN ? H Minimum Operating Voltage
The internal reference and core functions are powered by
either the VIN ? B or VIN ? H supply. The higher of the two
voltages will dominate and power the reference. This
provides quick circuit response on start ? up, as well as a
stable reference voltage. Since the VIN ? B voltage will come
up much more quickly than the VIN ? H voltage, initially, the
VIN ? B voltage will be running the reference. In the case of
any transient drops on VIN ? B, the VIN ? H supply, with its
large hold ? up capacitor, will then be the dominant voltage,
and will be powering the reference.
For proper operation of the device, VIN ? B or VIN ? H
must be at least 4.5 V. Below that voltage the reference will
not operate properly, leading to incorrect functioning by the
device. VIN ? B or VIN ? H must be greater than 4.5 V
regardless of the voltage on the VIN ? A pin.
Enable Function
The NCV8612B is equipped with an Enable input. By
keeping the Enable voltage below 0.8 V, the three outputs
will be held low. By increasing the Enable pin voltage above
2.0 V, the three outputs will be enabled to their regulated
output voltage.
Internal Soft ? Start
The NCV8612B is equipped with an internal soft ? start
function. This function is included to limit inrush currents
as can be seen in Figure 3.
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相关代理商/技术参数 |
参数描述 |
|---|---|
| NCV8612MNR2G | 功能描述:低压差稳压器 - LDO MULTIPLE OUTPUT LDO 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 |
| NCV8613 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Ultra-Low Iq Automotive System Power Supply IC Power Saving Triple-Output Linear Regulator |
| NCV8613B | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Ultra-Low Iq Automotive System Power Supply IC Power Saving Triple-Output Linear Regulator |
| NCV8613BMNR2G | 功能描述:线性稳压器 - 标准 ANA MULTIPLE OUTPUT LDO RoHS:否 制造商:STMicroelectronics 输出类型: 极性: 输出电压:1.8 V 输出电流:150 mA 负载调节: 最大输入电压:5.5 V 线路调整率: 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:SOT-323-5L |
| NCV8613MNR2G | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Ultra-Low Iq Automotive System Power Supply IC Power Saving Triple-Output Linear Regulator |
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