参数资料
型号: LTC3729LEUH-6#PBF
厂商: Linear Technology
文件页数: 16/28页
文件大小: 0K
描述: IC REG CTRLR BUCK PWM CM 32-QFN
标准包装: 73
系列: PolyPhase®
PWM 型: 电流模式
输出数: 1
频率 - 最大: 620kHz
占空比: 99.5%
电源电压: 4 V ~ 30 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: 32-WFQFN 裸露焊盘
包装: 管件
LTC3729L-6
APPLICATIO S I FOR ATIO
INTV CC Regulator
An internal P-channel low dropout regulator produces 5V
at the INTV CC pin from the V IN supply pin. The INTV CC
regulator powers the drivers and internal circuitry of the
LTC3729L-6. The INTV CC pin regulator can supply up to
50mA peak and must be bypassed to power ground with
a minimum of 4.7 μ F tantalum or electrolytic capacitor. An
additional 1 μ F ceramic capacitor placed very close to the
IC is recommended due to the extremely high instanta-
neous currents required by the MOSFET gate drivers.
High input voltage applications in which large MOSFETs
are being driven at high frequencies may cause the maxi-
mum junction temperature rating for the LTC3729L-6 to
be exceeded. The supply current is dominated by the gate
charge supply current, in addition to the current drawn
from the differential amplifier output. The gate charge is
dependent on operating frequency as discussed in the
Efficiency Considerations section. The supply current can
either be supplied by the internal 5V regulator or via the
EXTV CC pin. When the voltage applied to the EXTV CC pin
is less than 4.7V, all of the INTV CC load current is supplied
by the internal 5V linear regulator. Power dissipation for
the IC is higher in this case by (I IN )(V IN – INTV CC ) and
efficiency is lowered. The junction temperature can be
estimated by using the equations given in Note 1 of the
Electrical Characteristics. For example, the LTC3729L-6
V IN current is thermally limited to less than 54mA from a
30V supply:
T J = 70 ° C + (54mA)(30V)(34 ° C/W) = 125 ° C
Use of the EXTV CC pin reduces the junction temperature
to:
T J = 70 ° C + (54mA)(5V)(34 ° C/W) = 79.2 ° C
The input supply current should be measured while the
controller is operating in continuous mode at maximum
V IN and the power dissipation calculated in order to pre-
vent the maximum junction temperature from being ex-
ceeded.
EXTV CC Connection
The LTC3729L-6 contains an internal P-channel MOSFET
switch connected between the EXTV CC and INTV CC pins.
When the voltage applied to EXTV CC rises above 4.7V, the
16
internal regulator is turned off and the switch closes,
connecting the EXTV CC pin to the INTV CC pin thereby
supplying internal and MOSFET gate driving power. The
switch remains closed as long as the voltage applied to
EXTV CC remains above 4.5V. This allows the MOSFET
driver and control power to be derived from the output
during normal operation (4.7V < V EXTVCC < 7V) and from
the internal regulator when the output is out of regulation
(start-up, short-circuit). Do not apply greater than 7V to
the EXTV CC pin and ensure that EXTV CC < V IN + 0.3V when
using the application circuits shown. If an external voltage
source is applied to the EXTV CC pin when the V IN supply is
not present, a diode can be placed in series with the
LTC3729L-6’s V IN pin and a Schottky diode between the
EXTV CC and the V IN pin, to prevent current from backfeeding
V IN .
Significant efficiency gains can be realized by powering
INTV CC from the output, since the V IN current resulting
from the driver and control currents will be scaled by the
ratio: (Duty Factor)/(Efficiency). For 5V regulators this
means connecting the EXTV CC pin directly to V OUT . How-
ever, for 3.3V and other lower voltage regulators, addi-
tional circuitry is required to derive INTV CC power from the
output.
The following list summarizes the four possible connec-
tions for EXTV CC:
1. EXTV CC left open (or grounded). This will cause INTV CC
to be powered from the internal 5V regulator resulting in
a significant efficiency penalty at high input voltages.
2. EXTV CC connected directly to V OUT . This is the normal
connection for a 5V regulator and provides the highest
efficiency.
3. EXTV CC connected to an external supply. If an external
supply is available in the 5V to 7V range, it may be used to
power EXTV CC providing it is compatible with the MOSFET
gate drive requirements. V IN must be greater than or equal
to the voltage applied to the EXTV CC pin.
4. EXTV CC connected to an output-derived boost network.
For 3.3V and other low voltage regulators, efficiency gains
can still be realized by connecting EXTV CC to an output-
derived voltage which has been boosted to greater than
4.7V but less than 7V. This can be done with either the
sn3729l6 3729l6fs
相关PDF资料
PDF描述
H2ABT-10106-A4-ND JUMPER-H1502TR/A2015A/H1500TR 6"
LTC1628IUH#TRPBF IC REG CTRLR BUCK PWM CM 32-QFN
H2AAT-10104-Y4-ND JUMPER-H1502TR/A2015Y/H1502TR 4"
LTC1628IUH#TR IC REG CTRLR BUCK PWM CM 32-QFN
H2AAT-10104-W4-ND JUMPER-H1502TR/A2015W/H1502TR 4"
相关代理商/技术参数
参数描述
LTC3730CG 功能描述:IC SW REG CTRLR SYNC BUCK 36SSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器,Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN(7x7) 包装:管件
LTC3730CG#PBF 功能描述:IC SW REG CTRLR SYNC BUCK 36SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器,Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN(7x7) 包装:管件
LTC3730CG#TR 功能描述:IC CTRLR BUCK POLYPHASE 36-SSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器,Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN(7x7) 包装:管件
LTC3730CG#TRPBF 功能描述:IC SW REG CTRLR SYNC BUCK 36SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器,Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN(7x7) 包装:管件
LTC3731CG 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:PolyPhase® 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