参数资料
型号: LTC3728IUH#PBF
厂商: Linear Technology
文件页数: 1/36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: 2
频率 - 最大: 590kHz
占空比: 99%
电源电压: 3.5 V ~ 36 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
LTC3728
Dual, 550kHz, 2-Phase
Synchronous Step-Down
Switching Regulator
FEATURES
DESCRIPTION
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Dual, 180° Phased Controllers Reduce Required
Input Capacitance and Power Supply Induced Noise
OPTI-LOOP ? Compensation Minimizes C OUT
±1% Output Voltage Accuracy
Power Good Output Voltage Indicator
Phase-Lockable Fixed Frequency 250kHz to 550kHz
Dual N-Channel MOSFET Synchronous Drive
Wide V IN Range: 3.5V to 36V Operation
Very Low Dropout Operation: 99% Duty Cycle
Adjustable Soft-Start Current Ramping
Foldback Output Current Limiting
Latched Short-Circuit Shutdown with Defeat Option
Output Overvoltage Protection
Remote Output Voltage Sense
Low Shutdown I Q : 20μA
5V and 3.3V Regulators
3 Selectable Operating Modes: Constant-Frequency,
Burst Mode ? Operation and PWM
Available in 32-Pin 5mm × 5mm QFN and
The LTC ? 3728 is a dual high performance step-down
switching regulator controller that drives all N-channel
synchronous power MOSFET stages. A constant-frequency
current mode architecture allows phase-lockable frequency
of up to 550kHz. Power loss and noise due to the ESR of
the input capacitors are minimized by operating the two
controller output stages out of phase.
OPTI-LOOP compensation allows the transient response to
be optimized over a wide range of output capacitance and
ESR values. The precision 0.8V reference and power good
output indicator are compatible with future microprocessor
generations, and a wide 3.5V to 30V (36V maximum) input
supply range encompasses all battery chemistries.
A RUN/SS pin for each controller provides both soft-
start and optional timed, short-circuit shutdown. Current
foldback limits MOSFET dissipation during short-circuit
conditions when overcurrent latchoff is disabled. Output
overvoltage protection circuitry latches on the bottom
28-Pin SSOP Packages
APPLICATIONS
n Notebook and Palmtop Computers
MOSFET until V OUT returns to normal. The FCB mode
pin can select among Burst Mode, constant-frequency
mode and continuous inductor current mode or regulate
a secondary winding. The LTC3728 includes a power good
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Telecom Systems
Portable Instruments
Battery-Operated Digital Devices
DC Power Distribution Systems
output pin that indicates when both outputs are within
7.5% of their designed set point.
L , LT, LTC, LTM, Linear Technology, the Linear logo, Burst Mode and OPTI-LOOP are
registered trademarks of Linear Technology Corporation. All other trademarks are the property
of their respective owners. Protected by U.S. Patents including 5481178, 5929620, 6177787,
6144194, 6100678, 5408150, 6580258, 5705919.
TYPICAL APPLICATION
M1
4.7 μ F
+
D3
V IN PGOOD INTV CC
D4
1 μ F
M2
C IN
22 μ F
50V
V IN
5.2V TO 28V
TG1
TG2
L1
3.2 μ H
C B1 , 0.1 μ F
BOOST1
SW1
LTC3728
BOOST2
SW2
C B2 , 0.1 μ F
L2
3.2 μ H
BG1
BG2
f IN
500kHz
PLLIN
SENSE1 +
PGND
SENSE2 +
R SENSE1
0.01 Ω
1000pF
SENSE1 –
SENSE2 –
1000pF
R SENSE2
0.01 Ω
V OUT1
5V
5A
+
R2
C OUT1 105k
47 μ F 1%
6V
SP
R1
20k
1%
C C1
220pF
R C1
15k
V OSENSE1 V OSENSE2
I TH1 I TH2
RUN/SS1 SGND RUN/SS2
C SS1 C SS2
0.1 μ F 0.1 μ F
C C2
220pF
R C2
15k
R3
20k
1%
R4
63.4k
1%
C OUT
56 μ F
6V
SP
+
V OUT2
3.3V
5A
M1, M2: FDS6982S
Figure 1. High Ef?ciency Dual 5V/3.3V Step-Down Converter
3728 F01
3728fg
1
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相关代理商/技术参数
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LTC3728LCGN#PBF 功能描述:IC REG CTRLR BUCK PWM CM 28-SSOP RoHS:是 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
LTC3728LCGN#TR 功能描述:IC REG CTRLR BUCK PWM CM 28-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
LTC3728LCGN#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 28-SSOP RoHS:是 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
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