参数资料
| 型号： | LT1683EG#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 11/26页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR PWM CM 20-SSOP |
| 标准包装： | 66 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 250kHz |
| 占空比： | 46% |
| 电源电压： | 4 V ~ 20 V |
| 降压： | 无 |
| 升压： | 是 |
| 回扫： | 是 |
| 反相： | 是 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 125°C |
| 封装/外壳： | 20-SSOP（0.209"，5.30mm 宽） |
| 包装： | 管件 |
| 产品目录页面： | 1328 (CN2011-ZH PDF) |
LT1683
OPERATION
The voltage slew rate is thus inversely proportional to both
the value of capacitor and R VSL .
The current slew feedback loop consists of the voltage
across the external sense resistor, which is internally ampli-
fied and differentiated. The derivative is limited to a value set
by R CSL . The current slew rate is thus inversely proportional
to both the value of sense resistor and R CSL.
The two control loops are combined internally so that a
smooth transition from current slew control to voltage
slew control is obtained. When turning on, the driver cur-
rent will slew before voltage. When turning off, voltage
will slew before current. In general it is desirable to have
R VSL and R CSL of similar value.
Internal Regulator
Most of the control circuitry operates from an internal
2.4V low dropout regulator that is powered from V IN . The
internal low dropout design allows V IN to vary from 2.7V
to 20V with stable operation of the controller. When SHDN
< 1.3V the internal regulator is completely disabled.
5V Regulator
A 5V regulator is provided for powering external circuitry.
This regulator draws current from V IN and requires V IN
to be greater than 6.5V to be in regulation. It can sink or
source 10mA. The output is current limited to prevent
against destruction from accidental short circuits.
Safety and Protection Features
There are several safety and protection features on the
chip. The first is overcurrent limit. Normally the gate
drivers will go low when the output of the internal sense
amplifier exceeds the voltage on the V C pin. The V C pin is
clamped such that maximum output current is attained
when the CS pin voltage is 0.1V. At that level the outputs
will be immediately turned off (no slew). The effect of
this control is that the output voltage will foldback with
overcurrent.
In addition, if the CS voltage exceeds 0.22V, the V C and
SS pins will be discharged to ground also, resetting the
soft-start function. Thus if a short is present this will allow
for faster MOSFET turnoff and less MOSFET stress.
If the voltage on the FB pin exceeds regulation by ap-
proximately 0.22V, the outputs will immediately go low.
The implication is that there is an overvoltage fault.
The voltage on GCL determines two features. The first
is the maximum gate drive voltage. This will protect the
MOSFET gate from overvoltage.
With GCL tied to a Zener or an external voltage source
then the maximum gate driver voltage is approximately
V GCL – 0.2V. If GCL is tied to V IN , then the maximum
gate voltage is determined by V IN and is approximately
V IN – 1.6V. There is an internal 19V Zener on the GCL
pin that prevents the gate driver pin from exceeding ap-
proximately 19V.
In addition, the GCL voltage determines undervoltage
lockout of the gate drives. This feature disables the gate
drivers if V IN is too low to provide adequate voltage to
turn on the MOSFETs. This is helpful during start-up to
ensure the MOSFETs have sufficient gate drive to saturate.
If GCL is tied to a voltage source or Zener less than 6.8V,
the gate drivers will not turn on until V IN exceeds GCL
voltage by 0.8V. For V GCL above 6.5V, the gate drives are
ensured to be off for V IN < 7.3V and they will be turned
on by V GCL + 0.8V.
If GCL is tied to V IN , the gate drivers are always enabled
(undervoltage lockout is disabled).
When driving a push-pull transformer, it is important to
make sure that both drivers are not on at the same time.
Even though runaway cannot occur under such cross
conduction with this chip because current slew is regu-
lated, increased current would be possible. This chip has
opposite gate lockout whereby when one MOSFET is on
the other MOSFET cannot be turned on until the gate of
the first drops below 1V. This ensures that cross conduc-
tion will not occur.
The gate drives have current limits for the drive currents.
If the sink or source current is greater than 300mA then
the current will be limited.
The V5 regulator also has internal current limiting that will
only guarantee ±10mA output current.
1683fd
11
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相关代理商/技术参数 |
参数描述 |
|---|---|
| LT1683IG | 功能描述:IC REG CTRLR PWM CM 20-SSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:4,500 系列:PowerWise® PWM 型:控制器 输出数:1 频率 - 最大:1MHz 占空比:95% 电源电压:2.8 V ~ 5.5 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 125°C 封装/外壳:6-WDFN 裸露焊盘 包装:带卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名称:LM1771SSDX |
| LT1683IG#PBF | 功能描述:IC REG CTRLR PWM CM 20-SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:4,500 系列:PowerWise® PWM 型:控制器 输出数:1 频率 - 最大:1MHz 占空比:95% 电源电压:2.8 V ~ 5.5 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 125°C 封装/外壳:6-WDFN 裸露焊盘 包装:带卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名称:LM1771SSDX |
| LT1683IG#TR | 功能描述:IC REG CTRLR PWM CM 20-SSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:4,500 系列:PowerWise® PWM 型:控制器 输出数:1 频率 - 最大:1MHz 占空比:95% 电源电压:2.8 V ~ 5.5 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 125°C 封装/外壳:6-WDFN 裸露焊盘 包装:带卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名称:LM1771SSDX |
| LT1683IG#TRPBF | 功能描述:IC REG CTRLR PWM CM 20-SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:4,500 系列:PowerWise® PWM 型:控制器 输出数:1 频率 - 最大:1MHz 占空比:95% 电源电压:2.8 V ~ 5.5 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 125°C 封装/外壳:6-WDFN 裸露焊盘 包装:带卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名称:LM1771SSDX |
| LT1684 | 制造商:LINER 制造商全称:Linear Technology 功能描述:Micropower Ring Tone Generator |
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