- 您现在的位置：买卖IC网 > PDF目录1825 > LT3640IFE#TRPBF (Linear Technology)IC REG BUCK FIX/ADJ DL 28TSSOP PDF资料下载
参数资料
| 型号： | LT3640IFE#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 13/24页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK FIX/ADJ DL 28TSSOP |
| 标准包装： | 2,000 |
| 类型： | 降压（降压） |
| 输出类型： | 两者兼有 |
| 输出数： | 2 |
| 输出电压： | 1.8V，3.3V，可调 |
| 输入电压： | 2.5 V ~ 35 V |
| PWM 型： | 电流模式，混合 |
| 频率 - 开关： | 500kHz ~ 2MHz |
| 电流 - 输出： | 1.1A，1.3A |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-SOIC（0.173"，4.40mm 宽）裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 28-TSSOP 裸露焊盘 |
LT3640
APPLICATIONS INFORMATION
V IN ( MAX ) = ? OUT 1
? ? ? V D CE
? V + V D ?
V IN 2 ( MAX ) ≈
V OUT 1 + V D
f S
V IN 2 ( MIN ) ≈
? ? 1 – OUT 1
( V OUT 1 + V D ) ? V + V D ?
? ?
? I L 1 =
? I L
I L ( PEAK ) = I OUT ( MAX ) +
ThemaximumV IN shouldnotexceedtheabsolutemaxi-
mum rating. For fixed frequency operation, the maximum
V IN is:
+ V
? DC MIN
Note that the high voltage buck will still regulate at an input
voltage that exceeds V IN(MAX) (up to 35V). However, the
switching frequency will be lowered to satisfy the equa-
tion (Figure 1).
Once the input voltage reaches 36.5V, an internal overvoltage
lockout (OVLO) circuit is triggered to disable switching ac-
tion (Figure 2). Without switching, the LT3640 can sustain
V IN voltage transients up to 55V for one second.
V IN2 Voltage Range
The low voltage synchronous channel operates from
the V IN2 pin. The V IN2 pin can be connected to either an
independent voltage supply or the high voltage channel
output for a two-stage power regulator.
In either configuration, if the high voltage channel is over-
loaded and pulled out of regulation, the low voltage channel
will be disabled. The SS2 pin will be discharged as well.
The minimum V IN2 voltage to regulate output voltage is:
V OUT 2
DC MAX
Where DC MAX is the maximum duty cycle (refer to
the Switching Frequency section). If V IN2 is below the
SW1
10V/DIV
I L1
0.5A/DIV
calculated minimum voltage, the output will fall out of
regulation.
The maximum V IN2 for fixed frequency operation is:
V OUT 2
DC MIN
Where DC MIN is the minimum duty cycle (refer to the Switch-
ing Frequency section). For voltage that exceeds V IN2(MAX)
(up to 5.5V), the low voltage channel exhi-bits pulse-skip-
ping behavior, and the output ripple will increase.
Inductor Selection
Inductor selection involves inductance, saturation current,
series resistance (DCR) and magnetic loss.
The inductance for the high voltage channel is:
L 1 = 1 . 7 ?
where V OUT1 is high voltage channel output voltage, V D
is the forward voltage drop of the catch diode, and f S is
the switching frequency. For example, 3.3μH is a reason-
able inductance for a 3.3V output with 2MHz switching
frequency.
Once the inductance is selected, the inductor current ripple
and peak current can be calculated:
I L 1 ? f S ? V IN
2
I L1
2A/DIV
200ns/DIV
10μs/DIV
3640 F01
V IN = 30V R T SET = 2MHz
V OUT1 = 3.3V/0.2A
Figure 1. Lower Switching Frequency Occurs in High
Voltage Channel When Required On-Time Is Below 50ns
V IN
20V/DIV
55V PK , 40V, 15V
3640 F02
Figure 2. V IN Overvoltage Lockout
3640f
相关PDF资料 |
PDF描述 |
|---|---|
| LT3641HFE#TRPBF | IC REG BUCK SYNC ADJ DL 28TSSOP |
| LT3650IMSE-8.4#TRPBF | IC CHARGER LI-ION 8.4V 2A 12MSOP |
| LT3652EMSE#PBF | IC BATTERY CHARGER SOLAR 12MSOP |
| LT3653IDCB#TRPBF | IC REG BUCK ADJ 1.2A 8DFN |
| LT3663HMS8E-3.3#PBF | IC REG BUCK 3.3V 1.2A 8MSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LT3640IUFD | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Monolithic Buck Regulator with Power-On Reset and Watchdog Timer |
| LT3640IUFD#PBF | 功能描述:IC REG BUCK FIX/ADJ DL 28QFN 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 |
| LT3640IUFD#TRPBF | 功能描述:IC REG BUCK FIX/ADJ DL 28QFN 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 |
| LT3640IUFDPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Monolithic Buck Regulator with Power-On Reset and Watchdog Timer |
| LT3640IUFDTRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Monolithic Buck Regulator with Power-On Reset and Watchdog Timer |
发布紧急采购，3分钟左右您将得到回复。