- 您现在的位置：买卖IC网 > Sheet目录868 > LTM4608IV#PBF (Linear Technology)IC DC/DC UMODULE 8A 68-LGA
LTM4608
OPERATION
Current mode control provides cycle-by-cycle fast current
limit and thermal shutdown in an overcurrent condition.
Internal overvoltage and undervoltage comparators pull
the open-drain PGOOD output low if the output feedback
voltage exits a ±10% window around the regulation point.
Pulling the RUN pin below 1.3V forces the controller into
its shutdown state, by turning off both M1 and M2 at low
load current. The TRACK pin is used for programming the
output voltage ramp and voltage tracking during start-up.
See Applications Information.
The LTM4608 is internally compensated to be stable over
all operating conditions. Table 3 provides a guideline
for input and output capacitances for several operating
conditions. The Linear Technology μModule Power De-
sign Tool is provided for transient and stability analysis.
APPLICATIONS INFORMATION
The FB pin is used to program the output voltage with a
single external resistor to ground.
Multiphase operation can be easily employed with the
synchronization and phase mode controls. Up to 12 phases
can be cascaded to run simultaneously with respect to
each other by programming the PHMODE pin to different
levels. The LTM4608 has clock in and clock out for poly
phasing multiple devices or frequency synchronization.
High efficiency at light loads can be accomplished with
selectable Burst Mode operation using the MODE pin. These
light load features will accommodate battery operation.
Efficiency graphs are provided for light load operation in
the Typial Performance Characteristics.
Output voltage margining is supported, and can be pro-
gramed from ±5% to ±15% using the MGN and BSEL pins.
The PGOOD pin is disabled during margining.
The typical LTM4608 application circuit is shown in Fig-
ure 18. External component selection is primarily deter-
mined by the maximum load current and output voltage.
Refer to Table 3 for specific external capacitor requirements
for a particular application.
Table 2. R FB Resistor vs Output Voltage
V OUT 0.596V 1.2V 1.5V
R FB Open 10k 6.65k
Input Capacitors
1.8V
4.87k
2.5V
3.09k
3.3V
2.21k
V OUT
V IN
V IN toV OUT Step-DownRatios
There are restrictions in the maximum V IN to V OUT step-
down ratio that can be achieved for a given input voltage.
The LTM4608 is 100% duty cycle, but the V IN to V OUT
minimum dropout is a function of its load current. Please
refer to the curves in the Typical Performance Charac-
teristics section of this data sheet for more information.
Output Voltage Programming
The PWM controller has an internal 0.596V reference
voltage. As shown in the Block Diagram, a 10k/0.5%
internal feedback resistor connects V OUT and FB pins
together. The output voltage will default to 0.596V with
no feedback resistor. Adding a resistor R FB from FB pin
to GND programs the output voltage:
The LTM4608 module should be connected to a low AC
impedance DC source. Three 10μF ceramic capacitors
are included inside the module. Additional input capaci-
tors are only needed if a large load step is required up to
the 4A level. A 47μF to 100μF surface mount aluminum
electrolytic bulk capacitor can be used for more input bulk
capacitance. This bulk input capacitor is only needed if
the input source impedance is compromised by long in-
ductive leads, traces or not enough source capacitance.
If low impedance power planes are used, then this 47μF
capacitor is not needed.
For a buck converter, the switching duty-cycle can be
estimated as:
D =
V OUT = 0.596V ?
10
10k + R FB
R FB
4608fd
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
LTM4609IV#PBF
IC BUCK/BOOST SYNC ADJ 4A 141LGA
LTM4612IV#PBF
IC BUCK SYNC ADJ 5A 133LGA
LTM4613MPV#PBF
IC UMODULE DC/DC 8A 133-LGA
LTM4614IV#PBF
IC UMODULE DC/DC DUAL 4A 144LGA
LTM4615IV#PBF
IC SWIT REG BUCK 4A ADJ 144LGA
LTM4618IV#PBF
IC DC-DC UMODULE BUCK 6A 84-LGA
LTM4619IV#PBF
IC SWIT REG BUCK 4A ADJ 144LGA
LTM4627MPY#PBF
IC DC/DC UMODULE 15A 133-BGA
相关代理商/技术参数
LTM4608IV#PBF
制造商:Linear Technology 功能描述:IC SWITCH MODE DC/DC POWER SUPPLY LGA-68
LTM4608IVPBF
制造商:Linear Technology 功能描述:Conv DC-DC Single-OUT Step Down
LTM4608IV-PBF
制造商:LINER 制造商全称:Linear Technology 功能描述:Low VIN, 8A DC/DC μModuleTM with Tracking, Margining, and Frequency Synchronization
LTM4608V
制造商:LINER 制造商全称:Linear Technology 功能描述:Low VIN, 8A DC/DC μModuleTM with Tracking, Margining, and Frequency Synchronization
LTM4609
制造商:LINER 制造商全称:Linear Technology 功能描述:High Efficiency, Synchronous, 4-Switch Buck-Boost Controller
LTM4609_12
制造商:LINER 制造商全称:Linear Technology 功能描述:36VIN, 34VOUT High Efficiency Buck-Boost DC/DC
LTM4609EV
制造商:LINER 制造商全称:Linear Technology 功能描述:36VIN, 34VOUT High Effi ciency Buck-Boost DC/DC μModule
LTM4609EV#PBF
功能描述:IC UMODULE BUCK-BOOST 141-LGA RoHS:是 类别:电源 - 板载 >> DC DC Converters 系列:µModule® 设计资源:VI-200, VI-J00 Design Guide, Appl Manual 标准包装:1 系列:* 类型:隔离 输出数:1 电压 - 输入（最小）:66V 电压 - 输入（最大）:160V Voltage - Output 1:12V Voltage - Output 2:- Voltage - Output 3:- 电流 - 输出（最大）:* 电源（瓦） - 制造商系列:50W 电压 - 隔离:* 特点:* 安装类型:通孔 封装/外壳:9-FinMod 尺寸/尺寸:4.60" L x 1.86" W x 0.79" H（116.8mm x 47.2mm x 20.1mm） 包装:散装 工作温度:-25°C ~ 85°C 效率:* 电源（瓦特）- 最大:*