参数资料
型号: LTC3858EUH#TRPBF
厂商: Linear Technology
文件页数: 1/38页
文件大小: 0K
描述: IC REG CTRLR BUCK PWM CM 32-QFN
标准包装: 2,500
PWM 型: 电流模式
输出数: 2
频率 - 最大: 850kHz
占空比: 99.4%
电源电压: 4 V ~ 38 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 125°C
封装/外壳: 32-WFQFN 裸露焊盘
包装: 带卷 (TR)
LTC3858
Low I Q , Dual
2-Phase Synchronous
Step-Down Controller
FEATURES
DESCRIPTION
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Low Operating I Q : 170μA (One Channel On)
Wide Output Voltage Range: 0.8V ≤ V OUT ≤ 24V
Wide V IN Range: 4V to 38V
R SENSE or DCR Current Sensing
Out-of-Phase Controllers Reduce Required Input
Capacitance and Power Supply Induced Noise
OPTI-LOOP ? Compensation Minimizes C OUT
Phase-Lockable Frequency (75kHz-850kHz)
Programmable Fixed Frequency (50kHz-900kHz)
Selectable Continuous, Pulse-Skipping or
Burst Mode ? Operation at Light Loads
Very Low Dropout Operation: 99% Duty Cycle
Adjustable Output Voltage Soft-Start
Power Good Output Voltage Monitor
Output Overvoltage Protection
Output Latch-Off Protection During Short Circuit
Low Shutdown I Q : 8μA
Internal LDO Powers Gate Drive from V IN or EXTV CC
No Current Foldback During Start-Up
Small 5mm × 5mm QFN Package
The LTC ? 3858 is a high performance dual step-down
switching regulator controller that drives all N-channel
synchronous power MOSFET stages. A constant frequency
current mode architecture allows a phase-lockable fre-
quency of up to 850kHz. Power loss and noise due to the
input capacitor ESR are minimized by operating the two
controller outputs out of phase.
The 170μA no-load quiescent current extends operating
life in battery-powered systems. OPTI-LOOP compensa-
tion allows the transient response to be optimized over
a wide range of output capacitance and ESR values. The
LTC3858 features a precision 0.8V reference and a power
good output indicator. A wide 4V to 38V input supply range
encompasses a wide range of intermediate bus voltages
and battery chemistries.
Independent soft-start pins for each controller ramp the
output voltages during start-up. The output latch-off feature
protects the circuit in short-circuit conditions.
For a leaded 28-lead SSOP package with a ?xed current
APPLICATIONS
limit and one PGOOD output, without phase modulation
or a clock output, see the LTC3858-1 data sheet.
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Automotive Systems
Battery Operated Digital Devices
Distributed DC Power Systems
L , LT, LTC, LTM, Burst Mode, OPTI-LOOP, μModule, PolyPhase, Linear Technology and the Linear
logo are registered trademarks and No R SENSE and UltraFast are trademarks of Linear Technology
Corporation. All other trademarks are the property of their respective owners. Protected by U.S.
Patents, including 5481178, 5705919, 5929620, 6100678, 6144194, 6177787, 6304066, 6580258.
TYPICAL APPLICATION
High Ef?ciency Dual 8.5V/3.3V Step-Down Converter
4.7μF
22μF
50V
V IN
9V TO 38V
Ef?ciency and Power Loss
vs Load Current
V IN
INTV CC
100
10000
3.3μH
0.1μF
TG1
BOOST1
SW1
TG2
BOOST2
SW2
0.1μF
7.2μH
90
80
70
EFFICIENCY
1000
BG1
SENSE1 +
LTC3858
BG2
PGND
SENSE2 +
60
50
40
POWER LOSS
100
10
0.007Ω
0.01Ω
30
V OUT1
3.3V
5A
62.5k
150μF
680pF
SENSE1 –
V FB1
I TH1
SS1
SGND
SENSE2 –
V FB2
I TH2
SS2
680pF
20k
193k
V OUT2
8.5V
3.5A
150μF
20
10
0
0.0001
0.001
V IN = 12V
V OUT = 3.3V
FIGURE 12 CIRCUIT
0.01 0.1 1 10
1
0.1
20k
15k
0.1μF
0.1μF
15k
OUTPUT CURRENT (A)
3858 TA01b
3858 TA01
3858fc
1
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相关代理商/技术参数
参数描述
LTC3858IGN-1#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:- 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
LTC3858IGN-1#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:- 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
LTC3858IUFD-1#PBF 功能描述:IC REG CTRLR BUCK PWM CM 28-QFN 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
LTC3858IUFD-1#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 28-QFN 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
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