参数资料
型号: MCP1650DM-LED2
厂商: Microchip Technology
文件页数: 14/28页
文件大小: 0K
描述: BOARD DEMO FOR MCP1650 WHITE LED
标准包装: 1
电流 - 输出 / 通道: 15mA
输出及类型: 1,非隔离
输出电压: 32.4V
特点: 可调光
输入电压: 2.7 ~ 4.5V
已供物品:
已用 IC / 零件: MCP1650
MCP1650/51/52/53
4.7
FB Pin
4.11
Low Battery Detect
The output voltage is fed back through a resistor divider
to the FB pin. It is then compared to an internal 1.22V
reference. When the divided-down output is below the
internal reference, the internal oscillator is gated on
and the EXT pin pulses the external N-channel
MOSFET on and off to transfer energy from the source
to the load at 750 kHz. This will cause the output volt-
age to rise until it is above the 1.22V threshold, thereby
gating the internal oscillator off. Hysteresis is provided
within the comparator and is typically 12 mV. The rate
at which the oscillator is gated on and off is determined
by the input voltage, load current, hysteresis voltage
and inductance. The output ripple voltage will vary
depending on the input voltage, load current,
hysteresis voltage and inductance.
The Low-Battery Detect (MCP1651 and MCP1653
only) feature can be used to determine when the LBI
input voltage has fallen below a predetermined
threshold. The low-battery detect comparator
continuously monitors the voltage on the LBI pin. When
the voltage on the LBI pin is above the 1.22V + 123 mV
hysteresis, the LBO pin will be high-impedance (open-
drain). When in the high-impedance state, the leakage
current into the LBO pin is typically less than 0.1 μA. As
the voltage on the LBI pin decreases and is lower than
the 1.22V typical threshold, the LBO pin will transition
to a low state and is capable of sinking up to 10 mA.
123 mV of hysteresis is provided to prevent chattering
of the LBO pin as a result of battery input impedance
and boost input current.
4.8
PWM Latch
4.12
Power Good Output
The gated oscillator is self-latched to prevent double
and sporadic pulsing. The reset into the latch is asyn-
chronous and can terminate the pulse during the on-
time of the duty cycle. The reset can be accomplished
by the feedback voltage comparator or the current limit
comparator.
4.9 Peak Inductor Current
The external switch peak current is sensed on the CS
The Power Good Output feature (MCP1652 and
MCP1653 only) monitors the divided-down voltage
feedback into the FB pin. When the output voltage falls
more than 15% (typical) below the regulated set point,
the power good (PG) output pin will transition from a
high-impedance state (open-drain) to a low state
capable of sinking 10 mA. If the output voltage rises
more than 15% (typical) above the regulated set point,
the PG output pin will transition from high to low.
pin across an optional external current sense resistor.
If the CS pin falls more than 122 mV (typical) below
4.13
Device Protection
V IN , the current limit comparator is set and the pulse is
terminated. This prevents the current from getting too
high and damaging the N-channel MOSFET. In the
event of a short circuit, the switch current will be low
due to the current limit. However, there is a DC path
from the input through the inductor and external diode.
This is true for all boost-derived topologies and addi-
tional protection circuitry is necessary to prevent
catastrophic damage.
4.13.1 OVERCURRENT LIMIT
The Current Sense (CS) input pin is used to sense the
peak input current of the boost converter. This can be
used to limit how high the peak inductor current can
reach. The current sense feature is optional and can be
bypassed by connecting the V IN input pin to the CS
input pin. Because of the path from input through the
boost inductor and boost diode to output, the boost
topology cannot support a short circuit without
4.10
EXT Output Driver
additional circuitry. This is typical of all boost regulators.
The EXT output pin is designed to directly drive
external N-channel MOSFETs and is capable of
sourcing 400 mA (typical) and sinking 800 mA (typical)
for fast on and off transitions. The top side of the EXT
driver is connected directly to V IN , while the low side of
the driver is tied to GND, providing rail-to-rail drive
capability. Design flexibility is added by connecting an
external resistor in series with the N-channel MOSFET
to control the speed of the turn on and off. By slowing
the transition speed down, there will be less high-
frequency noise. Speeding the transition up produces
higher efficiency.
DS21876A-page 14
? 2004 Microchip Technology Inc.
相关PDF资料
PDF描述
T95S334K035CZAL CAP TANT 0.33UF 35V 10% 1507
T95S225M020CZAL CAP TANT 2.2UF 20V 20% 1507
T95S225M016CZAL CAP TANT 2.2UF 16V 20% 1507
T95S225K020CZAL CAP TANT 2.2UF 20V 10% 1507
T95S225K016CZAL CAP TANT 2.2UF 16V 10% 1507
相关代理商/技术参数
参数描述
MCP1650EV 功能描述:开发板和工具包 - PIC / DSPIC MCP1650 Boost Contr Eval Board RoHS:否 制造商:Microchip Technology 产品:Starter Kits 工具用于评估:chipKIT 核心:Uno32 接口类型: 工作电源电压:
MCP1650R-E/MS 功能描述:直流/直流开关转换器 UVLO 2V RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MCP1650R-E/MS 制造商:Microchip Technology Inc 功能描述:Controller IC
MCP1650REMS 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:750 kHz Boost Controller
MCP1650REUN 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:750 kHz Boost Controller