参数资料
型号: LTC3612IUDC#PBF
厂商: Linear Technology
文件页数: 14/30页
文件大小: 0K
描述: IC REG BUCK SYNC ADJ 3A 20QFN
标准包装: 91
类型: 降压(降压)
输出类型: 可调式
输出数: 1
输出电压: 0.6 V ~ 5.5 V
输入电压: 2.25 V ~ 5.5 V
PWM 型: 电流模式,混合
频率 - 开关: 300kHz ~ 4MHz
电流 - 输出: 3A
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: 20-WFQFN 裸露焊盘
包装: 管件
供应商设备封装: 20-QFN(3x4)
LTC3612
OPERATION
If the output voltage drops below 50% of its nominal value,
the clamp voltage at ITH pin is lowered causing the maxi-
mum peak inductor current to decrease gradually with the
output voltage. When the output voltage reaches 0V the
clamp voltage at the ITH pin drops to 40% of the clamp
voltage during normal operation. The short-circuit peak
inductor current is determined by the minimum on-time
of the LTC3612, the input voltage and the inductor value.
This foldback behavior helps in limiting the peak inductor
APPLICATIONS INFORMATION
The basic LTC3612 application circuit is shown in Figure 1.
Operating Frequency
current when the output is shorted to ground. It is disabled
during internal or external soft-start and tracking up/down
operation (see the Applications Information section).
A secondary limit is also imposed on the valley inductor
current. If the inductor current measured through the
bottom MOSFET increases beyond 6A typical, the top
power MOSFET will be held off and switching cycles will
be skipped until the inductor current is reduced.
ramp current that is used to charge and discharge an
internal timing capacitor within the oscillator and can be
calculated by using the following equation:
Selection of the operating frequency is a trade-off between
efficiency and component size. High frequency operation
allows the use of smaller inductor and capacitor values.
R T =
3.82 ?10 11 Hz
f OSC ( Hz )
? – 16k ?
Operation at lower frequencies improves efficiency by
reducing internal gate charge losses but requires larger
inductance values and/or capacitance to maintain low
output ripple voltage.
The operating frequency of the LTC3612 is determined
by an external resistor that is connected between the RT/
SYNC pin and ground. The value of the resistor sets the
Although frequencies as high as 4MHz are possible, the
minimum on-time of the LTC3612 imposes a minimum
limit on the operating duty cycle. The minimum on-time
is typically 60ns; therefore, the minimum duty cycle is
equal to 100 ? 60ns ? f OSC (Hz)%.
Tying the RT/SYNC pin to SV IN sets the default internal
operating frequency to 2.25MHz ±20%.
V IN
2.25V TO 5.5V
R SS
2M
C SS
22nF
R C
15k
C C
470pF
R T
130k
C C1
10pF
(OPT)
SV IN PV IN
RUN PV IN_DRV
TRACK/SS DDR
RT/SYNC
LTC3612 SW
PGOOD SGND
ITH PGND
MODE V FB
R2
196k
C IN1
22μF
L1
470nH
R1
392k
3612 F01
C IN2
22μF
C OUT1
47μF
V OUT
1.8V
C OUT2 3A
22μF
Figure 1. 1.8V, 3A Step-Down Regulator
3612fb
14
For more information www.linear.com/LTC3612
相关PDF资料
PDF描述
RBC13DRAS-S734 CONN EDGECARD 26POS .100 R/A EXT
MAX6795TPYD3+ IC REG LIN W/SPR VSR 20-TQFN
RSC05DRAI-S734 CONN EDGECARD 10POS .100 R/A PCB
MAX6795TPZD4+ IC REG LIN W/SPR VSR 20-TQFN
RMC05DRAI-S734 CONN EDGECARD 10POS .100 R/A PCB
相关代理商/技术参数
参数描述
LTC3613EWKH#PBF 功能描述:IC REG BUCK SYNC ADJ 15A 56-QFN 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
LTC3613EWKH#TRPBF 功能描述:IC REG BUCK SYNC ADJ 15A 56QFN 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
LTC3613IWKH#PBF 功能描述:IC REG BUCK SYNC ADJ 15A 56QFN 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
LTC3613IWKH#TRPBF 功能描述:IC REG BUCK SYNC ADJ 15A 56QFN 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
LTC3614EUDD#PBF 功能描述:IC REG BUCK SYNC ADJ 4A 24QFN 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