- 您现在的位置：买卖IC网 > PDF目录16185 > NCP346SN1EVB (ON Semiconductor)EVAL BOARD FOR NCP346SN1 PDF资料下载
参数资料
| 型号： | NCP346SN1EVB |
| 厂商： | ON Semiconductor |
| 文件页数： | 7/15页 |
| 文件大小： | 0K |
| 描述： | EVAL BOARD FOR NCP346SN1 |
| 产品变化通告： | Product Obsolescence 21/Jan/2010 |
| 设计资源： | NCP346SN1 Demo Brd BOM NCP346SN1EVB Gerber Files NCP346SN1 Demo Brd Schematic |
| 标准包装： | 1 |
| 主要目的： | 过压防护 |
| 嵌入式： | 否 |
| 已用 IC / 零件： | NCP346 |
| 已供物品： | 板 |
| 其它名称： | NCP346SN1EVBOS |
NCP346
Normal Operation
which equates to:
Figure 1 illustrates a typical configuration. The external
adapter provides power to the protection system so the
circuitry is only active when the adapter is connected. The
OVP monitors the voltage from the charger and if the
voltage exceeds the overvoltage threshold, V th , the OUT
VCC + Vx(1 ) R1 R2 ) R1 Rin)
So, as R in approaches infinity:
VCC + Vx(1 ) R1 R2)
(eq. 2)
(eq. 3)
(VCC, IN) + VCC * (R1 (R1 ) (R2 Rin)))
R1 (R1 ) (R2 Rin)) t 0.5
signal drives the gate of the MOSFET to within 1.0 V of
V CC , thus turning off the FET and disconnecting the source
from the load. The nominal time it takes to drive the gate to
this state is 400 nsec (1.0 m sec maximum for gate
capacitance of < 12 nF). The CNTRL input can be used to
interrupt charging and allow the microcontroller to measure
the cell voltage under a normal condition to get a more
accurate measure of the battery voltage. Once the
overvoltage is removed, the NCP346 will turn on the
MOSFET. The turn on circuitry is designed to turn on the
MOSFET more gradually to limit the in?rush current. This
characteristic is a function of the threshold of the MOSFET
and will vary depending on the device characteristics such
as the gate capacitance.
There are two events that will cause the OVP to drive the
gate of the FET to a HIGH state.
? Voltage on IN Rises Above the Overvoltage Detection
Threshold
? CNTRL Input is Driven to a Logic HIGH
Adjusting the Overvoltage Detection Point with
External Resistors
The separate IN and V CC pins allow the user to adjust the
overvoltage threshold, V th , upwards by adding a resistor
divider with the tap at the IN pin. However, R in does play a
significant role in the calculation since it is several
10’s of k W . The following equation shows the effects of R in .
This shows that R in shifts the V th detection point in
accordance to the ratio of R 1 / R in . However, if R 1 << R in ,
this shift can be minimized. The following steps show this
procedure.
Designing around the Maximum Voltage Rating
Requirements, V(V CC , IN)
The NCP346’s maximum breakdown voltage between
pins V CC and IN is 15 V. Therefore, care must be taken that
the design does not exceed this voltage. Normally, the
designer shorts V CC to IN, V(V CC , IN) is shorted to 0 V, so
there is no issue. However, one must take care when
adjusting the overvoltage threshold.
In Figure 4, the R1 resistor of the voltage divider divides
the V(V CC , IN) voltage to a given voltage threshold equal to:
(eq. 4)
V(V CC , IN) worst case equals 15 V, and V CC worst case
equals 30 V, therefore, one must ensure that:
(eq. 5)
Where 0.5 = V(V CC , IN)max/V CCmax
Therefore, the NCP346 should only be adjusted to
maximum overvoltage thresholds which are less than 15 V.
If greater thresholds are desired than can be accommodated
by the NCP346, ON Semiconductor offers the NCP345
which can withstand those voltages.
VCC + Vx(1 ) R1 (R2
V CC
R 1
I N
R 2
Rin))
R in
(eq. 1)
GND
Figure 4. Voltage divider input to adjust overvoltage
detection point
http://onsemi.com
7
相关PDF资料 |
PDF描述 |
|---|---|
| 383LX103M080A082 | CAP ALUM 10000UF 80V 20% SNAP |
| 383LX152M250A062 | CAP ALUM 1500UF 250V 20% SNAP |
| ESM15DSEP-S243 | CONN EDGECARD 30POS .156 EYELET |
| M3TMK-1606R | IDC CABLE - MSD16K/MC16M/MCG16K |
| 380LX561M400A052 | CAP ALUM 560UF 400V 20% SNAP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| NCP346SN1T1G | 功能描述:监控电路 4.45V Overvoltage Supervisor RoHS:否 制造商:STMicroelectronics 监测电压数: 监测电压: 欠电压阈值: 过电压阈值: 输出类型:Active Low, Open Drain 人工复位:Resettable 监视器:No Watchdog 电池备用开关:No Backup 上电复位延迟（典型值）:10 s 电源电压-最大:5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:UDFN-6 封装:Reel |
| NCP346SN2T1G | 功能描述:监控电路 5.5V Overvoltage Supervisor RoHS:否 制造商:STMicroelectronics 监测电压数: 监测电压: 欠电压阈值: 过电压阈值: 输出类型:Active Low, Open Drain 人工复位:Resettable 监视器:No Watchdog 电池备用开关:No Backup 上电复位延迟（典型值）:10 s 电源电压-最大:5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:UDFN-6 封装:Reel |
| NCP347AE AV51D WAF | 制造商:ON Semiconductor 功能描述: |
| NCP347AI BB58A WAF | 制造商:ON Semiconductor 功能描述: |
| NCP347MTAETBG | 功能描述:电池管理 OVER VLTG PROTECTION RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel |
发布紧急采购，3分钟左右您将得到回复。