参数资料
型号: LTC3610IWP#TRPBF
厂商: Linear Technology
文件页数: 15/24页
文件大小: 0K
描述: IC REG BUCK SYNC ADJ 12A 64QFN
标准包装: 2,000
类型: 降压(降压)
输出类型: 可调式
输出数: 1
输出电压: 0.6 V ~ 24 V
输入电压: 4 V ~ 24 V
PWM 型: 电流模式
电流 - 输出: 12A
同步整流器:
工作温度: -40°C ~ 125°C
安装类型: 表面贴装
封装/外壳: 64-VFQFN 裸露焊盘
包装: 带卷 (TR)
供应商设备封装: 64-QFN(9x9)
LTC3610
APPLICATIONS INFORMATION
When the voltage on RUN/SS reaches 1.5V, the LTC3610
begins operating with a clamp on I TH of approximately
0.9V. As the RUN/SS voltage rises to 3V, the clamp on I TH
is raised until its full 2.4V range is available. This takes an
additional 1.3s/μF, during which the load current is folded
back until the output reaches 75% of its final value.
3.3V OR 5V
D1
V IN
RUN/SS
R SS *
C SS
INTV CC
R SS *
D2*
2N7002
RUN/SS
C SS
After the controller has been started and given adequate
time to charge up the output capacitor, C SS is used as a
short-circuit timer. After the RUN/SS pin charges above 4V,
if the output voltage falls below 75% of its regulated value,
then a short-circuit fault is assumed. A 1.8μA current then
begins discharging C SS . If the fault condition persists until
the RUN/SS pin drops to 3.5V, then the controller turns
off both power MOSFETs, shutting down the converter
permanently. The RUN/SS pin must be actively pulled
down to ground in order to restart operation.
The overcurrent protection timer requires that the soft-start
timing capacitor, C SS , be made large enough to guarantee
that the output is in regulation by the time C SS has reached
the 4V threshold. In general, this will depend upon the
size of the output capacitance, output voltage and load
current characteristic. A minimum soft-start capacitor
can be estimated from:
C SS > C OUT V OUT R SENSE (10 –4 [F/V s])
Generally 0.1μF is more than sufficient.
Overcurrent latchoff operation is not always needed or de-
sired. Load current is already limited during a short-circuit
by the current foldback circuitry and latchoff operation can
prove annoying during troubleshooting. The feature can
be overridden by adding a pull-up current greater than
5μA to the RUN/SS pin. The additional current prevents
the discharge of C SS during a fault and also shortens the
soft-start period. Using a resistor to V IN as shown in Fig-
ure 5a is simple, but slightly increases shutdown current.
Connecting a resistor to INTV CC as shown in Figure 5b
eliminates the additional shutdown current, but requires
a diode to isolate C SS . Any pull-up network must be able
to pull RUN/SS above the 4.2V maximum threshold of the
latchoff circuit and overcome the 4μA maximum discharge
current.
3610 F05
*OPTIONAL TO OVERRIDE
OVERCURRENT LATCHOFF
(5a) (5b)
Figure 5. RUN/SS Pin Interfacing with Latchoff Defeated
Efficiency Considerations
The percent efficiency of a switching regulator is equal to
the output power divided by the input power times 100%.
It is often useful to analyze individual losses to determine
what is limiting the efficiency and which change would
produce the most improvement. Although all dissipative
elements in the circuit produce losses, four main sources
account for most of the losses in LTC3610 circuits:
1. DC I 2 R losses. These arise from the resistance of the
internal resistance of the MOSFETs, inductor and PC
board traces and cause the efficiency to drop at high
output currents. In continuous mode the average output
current flows through L, but is chopped between the top
and bottom MOSFETs. The DC I 2 R loss for one MOSFET
can simply be determined by [R DS(ON) + R L ] ? I O .
2. Transition loss. This loss arises from the brief amount
of time the top MOSFET spends in the saturated re-
gion during switch node transitions. It depends upon
the input voltage, load current, driver strength and
MOSFET capacitance, among other factors. The loss
is significant at input voltages above 20V and can be
estimated from:
Transition Loss ? (1.7A –1 ) V IN2 I OUT C RSS f
3. INTV CC current. This is the sum of the MOSFET driver
and control currents. This loss can be reduced by sup-
plying INTV CC current through the EXTV CC pin from a
high efficiency source, such as an output derived boost
network or alternate supply if available.
3610ff
  
相关PDF资料
PDF描述
V375B8E200B CONVERTER MOD DC/DC 8V 200W
LTC3613EWKH#TRPBF IC REG BUCK SYNC ADJ 15A 56QFN
LTC3611EWP#TRPBF IC REG BUCK SYNC ADJ 10A 64QFN
V375B5E200BG3 CONVERTER MOD DC/DC 5V 200W
V375B5E200B2 CONVERTER MOD DC/DC 5V 200W
相关代理商/技术参数
参数描述
LTC3611EWP#PBF 功能描述:IC REG BUCK SYNC ADJ 10A 64QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:250 系列:- 类型:降压(降压) 输出类型:固定 输出数:1 输出电压:1.2V 输入电压:2.05 V ~ 6 V PWM 型:电压模式 频率 - 开关:2MHz 电流 - 输出:500mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:6-UFDFN 包装:带卷 (TR) 供应商设备封装:6-SON(1.45x1) 产品目录页面:1032 (CN2011-ZH PDF) 其它名称:296-25628-2
LTC3611EWP#TRPBF 功能描述:IC REG BUCK SYNC ADJ 10A 64QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压(升压) 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-5 细型,TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT
LTC3611IWP#PBF 功能描述:IC REG BUCK SYNC ADJ 10A 64QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压(升压) 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-5 细型,TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT
LTC3611IWP#TRPBF 功能描述:IC REG BUCK SYNC ADJ 10A 64QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压(升压) 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-5 细型,TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT
LTC3612EFE#PBF 功能描述:IC REG BUCK SYNC ADJ 3A 20TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压(升压) 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-5 细型,TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT