Micrel, Inc.
MIC2310
July 2008
25
M9999-070108-A
Shorted C
PRIMARY
Detector Asserts HW_FLT at
Start-up
In order to protect the system from the result of the
installation of a shorted or excessively large C
PRIMARY
capacitor on the PCB, the controller incorporates a
shorted C
PRIMARY
detection scheme. A shorted
CPRIMARY pin or an excessively large C
PRIMARY
capacitor will impact the primary OC detection time,
t
POC.
The operation of the shorted C
PRIMARY
detection
scheme at start-up is described in Figure 12. Prior to
power-up, the CPRIMARY pin is discharged to 0V. As
the applied V
CC
supply and the internal V
REG
voltage
rise, a 3mA current source is applied to the
CPRIMARY pin to charge C
PRIMARY
to V
REG
. When the
internal V
REG
voltage is above the controllers
V
VREG(UVLOH)
threshold voltage, the t
POR
timer is
initiated. For the case of a reasonable C
PRIMARY
capacitor value, one which keeps the primary OC
response time, t
POC
, less than 0.5s, C
PRIMARY
charges
above V
PRIH
before the POR timer terminates and
normal operation commences. However, if the
CPRIMARY pin is shorted to GND or C
PRIMARY
is too
large, as in this timing diagram, the POR timer
terminates before C
PRIMARY
charges above V
PRIH
and a
shorted C
PRIMARY
is detected. When a C
PRIMARY
short is
detected, the GATE drive circuit and the DISCH
output are not affected, however, the HW_FLT digital
output is asserted. To repair the damaged C
PRIMARY
capacitor and reset the HW_FLT digital output, the
service processor instructs the main supply to turn off
the V
CC
supply voltage to the controller such that V
REG
falls below the controllers V
VREG(UVLOL)
threshold
voltage.
V
CC
& V
REG
ENABLE
GATE
V
OUT
I
LOAD
PWRGD
CPRIMARY
HW_FLT
DISCH
V
VREG(UVLOL)
V
VREG(UVLOH)
V
VREG(UVLOH)
V
GSPGH
V
PGH
V
GSPGH
tPOR
VPRIH
CPRIMARY TOO LARGE
VPRIH
t
POR
SMALLER CPRIMARY
V
PGL
Figure 12. Shorted C
PRIMARY
Detector Asserts HW_FLT at Start-up
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
MIC2341-2YTQ
IC HOT PLUG CTLR DUAL PCI 48TQFP
MIC2569YQS TR
IC POWER SWITCH CABLECARD 16QSOP
MIC2583R-MBQS TR
IC CTRLR HOT SWAP 200MV 16-QSOP
MIC2585-2MBTS TR
IC CTRLR HOT SWAP DUAL 24-TSSOP
MIC2586R-2BM TR
IC CTRLR/SEQ HOT SWAP 14-SOIC
MIC2587R-2BM TR
IC CTRLR HOT SWAP POS HV 8-SOIC
MIC2590B-5BTQ TR
IC PCI HOT PLUG CTLR DUAL 48TQFP
MIC2591B-2BTQ TR
IC PCI HOT PLUG CTLR DUAL 48TQFP
相关代理商/技术参数
MIC23150-4YMT EV
功能描述:电源管理IC开发工具 2.0A 4MHz HyperLight Load Buck Regulator - Evaluation Board
RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
MIC23150-4YMT TR
功能描述:直流/直流开关调节器 2.0A 4MHz HyperLight Load Buck Regulator
RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
MIC23150-4YMT-TR
功能描述:Buck Switching Regulator IC Positive Fixed 1.2V 1 Output 2A 8-VFDFN Exposed Pad, 8-MLF? 制造商:microchip technology 系列:HyperLight Load? 包装:剪切带（CT） 零件状态:有效 功能:降压 输出配置:正 拓扑:降压 输出类型:固定 输出数:1 电压 - 输入（最小值）:2.7V 电压 - 输入（最大值）:5.5V 电压 - 输出（最小值/固定）:1.2V 电压 - 输出（最大值）:- 电流 - 输出:2A 频率 - 开关:4MHz 同步整流器:是 工作温度:-40°C ~ 125°C （TJ） 安装类型:表面贴装 封装/外壳:8-VFDFN 裸露焊盘，8-MLF? 供应商器件封装:8-MLF?（2x2） 标准包装:1
MIC23150-55YMT TR
功能描述:直流/直流开关调节器 2.0A 4MHz HyperLight Load Buck Regulator
RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
MIC23150-55YMT-TR
功能描述:Buck Switching Regulator IC Positive Fixed 1.35V 1 Output 2A 8-UFDFN 制造商:microchip technology 系列:HyperLight Load? 包装:剪切带（CT） 零件状态:停产 功能:降压 输出配置:正 拓扑:降压 输出类型:固定 输出数:1 电压 - 输入（最小值）:2.7V 电压 - 输入（最大值）:5.5V 电压 - 输出（最小值/固定）:1.35V 电压 - 输出（最大值）:- 电流 - 输出:2A 频率 - 开关:4MHz 同步整流器:是 工作温度:-40°C ~ 125°C （TJ） 安装类型:表面贴装 封装/外壳:8-UFDFN 供应商器件封装:8-TDFN（2x2） 标准包装:1
MIC23150-CYMT EV
功能描述:电源管理IC开发工具 2.0A 4MHz HyperLight Load Buck Regulator - Evaluation Board
RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
MIC23150-CYMT TR
功能描述:直流/直流开关调节器 1.5A 4MHz HyperLight Load Buck Regulator
RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
MIC23150-CYMT-TR
功能描述:Buck Switching Regulator IC Positive Fixed 1V 1 Output 2A 8-VFDFN Exposed Pad, 8-MLF? 制造商:microchip technology 系列:HyperLight Load? 包装:剪切带（CT） 零件状态:停产 功能:降压 输出配置:正 拓扑:降压 输出类型:固定 输出数:1 电压 - 输入（最小值）:2.7V 电压 - 输入（最大值）:5.5V 电压 - 输出（最小值/固定）:1V 电压 - 输出（最大值）:- 电流 - 输出:2A 频率 - 开关:4MHz 同步整流器:是 工作温度:-40°C ~ 125°C （TJ） 安装类型:表面贴装 封装/外壳:8-VFDFN 裸露焊盘，8-MLF? 供应商器件封装:8-MLF?（2x2） 标准包装:1