参数资料
型号: LTC3806EDE
厂商: Linear Technology
文件页数: 8/20页
文件大小: 0K
描述: IC REG CTRLR FLYBACK PWM 12-DFN
标准包装: 91
PWM 型: 电流模式
输出数: 1
频率 - 最大: 290kHz
占空比: 94%
电源电压: 10 V ~ 75 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 85°C
封装/外壳: 12-WFDFN 裸露焊盘
包装: 管件
LTC3806
OPERATIO
Main Control Loop
The LTC3806 is a constant frequency, current mode
flyback converter controller. A secondary-side gate driver
capable of driving several MOSFET synchronous rectifiers
is provided. To insure best cross regulation, DC/DC con-
verters using this controller operate in forced continuous
conduction (current is always flowing in either the primary
or secondary winding(s) of the transformer.)
For circuit operation, please refer to the Block Diagram of
the IC and Figure 1. In normal operation, the primary-side
power MOSFET is turned on when the oscillator sets the
PWM latch and is turned off when the current comparator
C1 resets the latch. V OUT1 is divided down and compared
to an internal 1.230V reference by error amplifier EA,
which outputs an error signal at the I TH pin. The voltage of
the I TH pin sets the current comparator C1 input threshold.
When the load current on either output increases, a fall in
the FB voltage relative to the reference voltage causes the
I TH pin to rise increasing the primary-side peak current
thereby maintaining regulation. Regulation of V OUT2 is
indirect, occurring via transformer action.
The RUN pin and undervoltage comparators control
whether the IC is enabled or is in a low current state. With
the RUN pin below 1.139V, the chip is off and the input
supply current is typically only 50 μ A. If the RUN pin is
above 1.230V, most internal circuitry remains off until V IN
exceeds the undervoltage comparator UV2 threshold. This
reduces start-up current to approximately 80 μ A allowing
smaller values for C1 and larger values for R1 to be used.
The undervoltage comparator UV1 keeps G1 and G2 low
until INTV CC voltage is > 4.7V to insure that gate drivers
will switch the external power MOSFETs properly.
Prior to normal operation, soft-start pin SS is low clamp-
ing the output of the V-to-I converter to a low value causing
current comparator C1 to trip at a low threshold. Once
operation begins, the SS pin ramps up causing the clamp
voltage to rise as well. This allows progressively higher
trip points on comparator C1 and progressively higher
peak currents to be supplied to the primary of the trans-
former. Soft-start is completed when the voltage on the SS
pin exceeds the voltage on the I TH pin.
The nominal operating frequency of the LTC3806 is 250kHz.
Since forced continuous operation is used, the noise
spectrum over all operating conditions is well controlled
with virtually all noise occurring at the operating frequency
and its harmonics.
3806fb
8
相关PDF资料
PDF描述
LTC3812IFE-5#TRPBF IC REG CTRLR BUCK PWM CM 16TSSOP
LTC3806EDE#PBF IC REG CTRLR FLYBACK PWM 12-DFN
LTC1266CS#TRPBF IC REG CTRLR BST PWM CM 16-SOIC
VE-JWD-EY-F3 CONVERTER MOD DC/DC 85V 50W
LTC1266CS#TR IC REG CTRLR BST PWM CM 16-SOIC
相关代理商/技术参数
参数描述
LTC3806EDE#PBF 功能描述:IC REG CTRLR FLYBACK PWM 12-DFN 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:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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:24-WQFN 裸露焊盘 包装:带卷 (TR)
LTC3806EDE#TR 功能描述:IC REG CTRLR FLYBACK PWM 12-DFN 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:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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:24-WQFN 裸露焊盘 包装:带卷 (TR)
LTC3806EDE#TRPBF 功能描述:IC REG CTRLR FLYBACK PWM 12-DFN 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:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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:24-WQFN 裸露焊盘 包装:带卷 (TR)
LTC3808EDE 制造商:Linear Technology 功能描述:DC DC Cntrlr Single-OUT Sync Step Down 2.75V to 9.8V Input 14-Pin DFN EP
LTC3808EDE#PBF 功能描述:IC REG CTRLR BUCK PWM CM 14-DFN 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:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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:24-WQFN 裸露焊盘 包装:带卷 (TR)