- 您现在的位置：买卖IC网 > PDF目录20364 > MAX5079EUD+ (Maxim Integrated)IC CNTRL ORING MOSFET 14TSSOP PDF资料下载
参数资料
| 型号： | MAX5079EUD+ |
| 厂商： | Maxim Integrated |
| 文件页数： | 12/18页 |
| 文件大小： | 0K |
| 描述： | IC CNTRL ORING MOSFET 14TSSOP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 96 |
| 应用： | 基站网络线路卡，服务器 |
| FET 型： | N 沟道 |
| 输出数： | 1 |
| 内部开关： | 无 |
| 延迟时间 - 开启： | 10µs |
| 延迟时间 - 关闭： | 70ns |
| 电源电压： | 2.75 V ~ 13.2 V |
| 电流 - 电源： | 4mA |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 14-TSSOP（0.173"，4.40mm 宽） |
| 供应商设备封装： | 14-TSSOP |
| 包装： | 管件 |
ORing MOSFET Controller with
Ultra-Fast 200ns Turn-Off
5) PS1, PS2, PS3 are present and PS1 goes open.
PS1’s output capacitors discharge and V OUT1 drops
below V BUS . The MAX5079 (U1) senses a negative
potential from V OUT1 to V BUS . Depending upon how
fast PS1’s output capacitor discharges, N1 is turned off
due to the crossing of the fast- or slow-comparator
reverse voltage threshold. N1’s gate is discharged with
a 2A sink current into GATE (U1), turning off N1 and
isolating PS1 from the BUS. The load-sharing circuit of
PS2 and PS3 will increase PS2 and PS3’s load current
until the total BUS current requirement is satisfied.
6) PS1, PS2, PS3 are present and providing BUS
current. PS1 loses its feedback signal and goes
into an overvoltage condition.
V BUS increases and PS1 is loaded heavily. The current
share circuit forces V OUT2 and V OUT3 higher and they
will eventually saturate at their current-sharing voltage
range. Now only PS1 has a positive voltage at IN (U1)
with respect to BUS. All OVI inputs will sense the over-
voltage, but only OVP (U1) will be asserted and latched
low. GATE (U1) is pulled to PGND and remains low as
long as V OVI ≥ 0.6V. When V OVI drops below 0.6V, OVP
remains low, however, U1 tries to turn on N1 unless
V OUT1 is actively kept below the undervoltage lockout.
Use OVP (U1) to either drive the cathode of an opto-
coupler to shutdown PS1 from the primary, or fire an
SCR connected between IN (U1) and PGND.
Internal and External
Undervoltage Lockout
The internal undervoltage lockout monitors V IN and
V AUXIN and keeps the MAX5079 off until either voltage
reaches 2.75V. Once powered and V IN and/or V AUXIN
increase above 2.75V, the external UVLO is monitored.
The external undervoltage lockout feature monitors the
UVLO input and keeps the MAX5079 off (GATE shorted
to PGND) until V UVLO is greater than 0.66V. Connect a
resistive divider from IN to UVLO to GND or from
AUXIN to UVLO to GND to set the external undervolt-
age lockout threshold. We advise setting the external
UVLO ≥ 2.75V when AUXIN is not present.
Charge Pump
The MAX5079 has an internal charge pump that pumps
the gate-drive voltage (V GATE ) high enough to fully
enhance the n-channel ORing MOSFET. The charge
pump is divided into two stages, a voltage doubler run-
ning at 70kHz using an external charge-pump capaci-
tor (C EXT ), and a voltage tripler running at 1MHz using
an internal capacitor.
Connect an external capacitor (C EXT ) between C+ and
C-. C EXT is charged from the higher of V IN or V AUXIN .
When the rising V IN becomes greater then V BUS (V UVLO
> 0.66V), C EXT is discharged through GATE into the
external MOSFET ’s gate capacitance. The charge-
pump output is controlled by an internal regulator. The
charge-pump output at GATE sources typically 2mA.
This provides enough current drive to turn on a typical
ORing MOSFET in less than 10μs. When (V GATE - V IN )
reaches the target value (depending on V IN ) the charge
pump is switched off (see the Electrical Characteristics
table). Choose C EXT equal to 10 times the ORing
MOSFET gate capacitance. Too low of a capacitance
will delay the turn-on of the ORing MOSFET, while too
high of a capacitance can cause excessive ripple at
V IN . Bypass IN to GND with a 1μF ceramic capacitor to
avoid ripple at IN caused by the charge-pump switch-
ing. A clamp is placed internally between GATE and IN
to prevent (V GATE - V IN ) from exceeding 11V. When V IN
is less than 5V, the charge pump (tripler) will increase
V GATE to 3x’s V IN to further reduce the R DSON of the
ORing MOSFET. The internal charge-pump booster
(voltage tripler) section is operational only when V IN and
V AUXIN are low and is turned off when V IN exceeds 5V.
When an additional supply is connected to AUXIN and
(V AUXIN - V IN ) > 5V, both charge pumps are completely
disabled. In this case, the charging of the ORing gate
comes entirely from V AUXIN . In this case, the charge-
pump flying capacitor can be eliminated and C+, C-
can be left floating.
GATE Drive and Gate Pulldown
The MAX5079’s charge pump provides bias to charge
the ORing MOSFET gate above IN (the MOSFET ’s
source). GATE source current and the turn-on speed
depends upon the value of C EXT (connected between
C+ and C-). Typically GATE can source up to 2mA with
C EXT = 0.1μF. This enables V GATE to rise to over 2V
above V IN in less than 10μs for an ORing MOSFET gate
capacitance of up to 10nF. With V IN < 5V, 12V MOSFETs
can be used for better R DSON characteristics. The
MAX5079 automatically selects the gate-drive voltage for
12
______________________________________________________________________________________
相关PDF资料 |
PDF描述 |
|---|---|
| MAX5944ESE+ | IC FW CURR LIMITER DUAL 16-SOIC |
| EMC05DRTI | CONN EDGECARD 10POS .100 EXTEND |
| MAX8585EUA+ | IC CNTRLR ORING MOSFET 8-MSOP |
| MLG0603S11NJ | INDUCTOR MULTILAYER 11NH 0201 |
| ESC08DRTH | CONN EDGECARD 16POS DIP .100 SLD |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX5079EUD+ | 功能描述:功率驱动器IC ORing MOSFET Controller RoHS:否 制造商:Micrel 产品:MOSFET Gate Drivers 类型:Low Cost High or Low Side MOSFET Driver 上升时间: 下降时间: 电源电压-最大:30 V 电源电压-最小:2.75 V 电源电流: 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Tube |
| MAX5079EUD+T | 功能描述:功率驱动器IC ORing MOSFET Controller RoHS:否 制造商:Micrel 产品:MOSFET Gate Drivers 类型:Low Cost High or Low Side MOSFET Driver 上升时间: 下降时间: 电源电压-最大:30 V 电源电压-最小:2.75 V 电源电流: 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Tube |
| MAX5079EUD+TG48 | 制造商:Maxim Integrated Products 功能描述:ORING MOSFET CONTROLLER WITH ULTRA-FAST 200NS TURN-OFF - Tape and Reel |
| MAX5079EUD-T | 功能描述:功率驱动器IC RoHS:否 制造商:Micrel 产品:MOSFET Gate Drivers 类型:Low Cost High or Low Side MOSFET Driver 上升时间: 下降时间: 电源电压-最大:30 V 电源电压-最小:2.75 V 电源电流: 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Tube |
| MAX5079EVKIT | 功能描述:电源管理IC开发工具 MAX5079 Eval Kit 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 |
发布紧急采购，3分钟左右您将得到回复。