- 您现在的位置：买卖IC网 > PDF目录1823 > LT1943EFE#TRPBF (Linear Technology)IC REG SW QUAD TFT LCD 28-TSSOP PDF资料下载
参数资料
| 型号： | LT1943EFE#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 17/20页 |
| 文件大小： | 0K |
| 描述： | IC REG SW QUAD TFT LCD 28-TSSOP |
| 标准包装： | 2,000 |
| 应用： | 转换器，TFT，LCD |
| 输入电压： | 4.5 V ~ 22 V |
| 输出数： | 4 |
| 输出电压： | 1.25 V ~ 40 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-SOIC（0.173"，4.40mm 宽）裸露焊盘 |
| 供应商设备封装： | 28-TSSOP 裸露焊盘 |
| 包装： | 带卷 (TR) |
LT1943
OPERATIO
should be 5 ? of resistance between the V ON pin and its
connection to the load, as shown on Figure 3. The resis-
tance will damp resonant tank circuit created by the output
short. As the transient on the V ON pin during a short-circuit
condition will be highly dependent on the layout and the
type of short, be sure to test the short condition and
examine the voltage at the V ON pin to check that it does not
swing below ground.
V ON
and inverting regulators, the switched currents flow through
the power switch, the switching diode, and the tank
capacitor. The loop formed by the components in the
switched current path should be as small as possible.
Place these components, along with the inductor and
output capacitor, on the same side of the circuit board, and
connect them on that layer. Place a local, unbroken ground
plane below these components, and tie this ground plane
to system ground at one location, ideally at the ground
terminal of the output capacitor C2. Additionally, keep the
R1
5 ?
TO LOAD
SW and BOOST nodes as small as possible.
C1
0.47 μ F
R1 IS ONLY NECESSARY
IF LOAD MAY HAVE TRANSIENT
SHORT CONDITION. OTHERWISE,
CONNECT V ON PIN DIRECTLY TO LOAD
1943 F03
Thermal Considerations
The PCB must provide heat sinking to keep the LT1943
cool. The exposed pad on the bottom of the package must
Figure 3. Transient Short Protection for V ON Pin
Printed Circuit Board Layout
For proper operation and minimum EMI, care must be
taken during printed circuit board (PCB) layout. Figure 4
shows the high-current paths in the step down regulator
circuit. Note that in the step-down regulators, large,
switched currents flow in the power switch, the catch
diode, and the input capacitor. In the step-up regulators,
large, switched currents flow through the power switch,
the switching diode, and the output capacitor. In SEPIC
be soldered to a ground plane. This ground should be tied
to other copper layers below with thermal vias; these
layers will spread the heat dissipated by the LT1943. Place
additional vias near the catch diodes. Adding more copper
to the top and bottom layers and tying this copper to the
internal planes with vias can reduce thermal resistance
further. With these steps, the thermal resistance from die
(or junction) to ambient can be reduced to θ JA = 25 ° C or
less. With 100LFPM airflow, this resistance can fall by
another 25%. Further increases in airflow will lead to lower
thermal resistance.
V IN
GND
SW
(a)
V IN
GND
SW
(b)
V SW
V IN
SW
L1
I C1
C1
GND
D1
C2
1943 F04
(c)
Figure 4. Subtracting the Current when the Switch is ON (a) From the Current when the Switch is OFF (b) Reveals the Path of
the High Frequency Switching Current (c) Keep this Loop Small. The Voltage on the SW and BOOST Nodes will also be
Switched; Keep these Nodes as Small as Possible. Finally, Make Sure the Circuit is Shielded with a Local Ground Plane
1943fa
17
相关PDF资料 |
PDF描述 |
|---|---|
| LT1944-1EMS#TR | IC REG BST ADJ 0.1A/175MA 10MSOP |
| LT1945IMS#TRPBF | IC REG MULTI CONFIG ADJ 10MSOP |
| LT1946EMS8E#TRPBF | IC REG BOOST 1.5A 8MSOP |
| LT1947EMSE#TRPBF | IC REG TFT-LCD ADJ 10-MSOP |
| LT1949IS8#TRPBF | IC REG BOOST ADJ 1A 8SOIC |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LT1944 | 制造商:LINER 制造商全称:Linear Technology 功能描述:Quad DCDC Converter for Triple Outputs TFT Supply Plus LED Driver |
| LT1944-1 | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Micropower Step-Up DC/DC Converter |
| LT1944-1EMS | 功能描述:IC REG BST ADJ 0.1A/175MA 10MSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:升压（升压） 输出类型:可调式 输出数:1 输出电压:1.24 V ~ 30 V 输入电压:1.5 V ~ 12 V PWM 型:电流模式，混合 频率 - 开关:600kHz 电流 - 输出:500mA 同步整流器:无 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) 供应商设备封装:8-SOIC |
| LT1944-1EMS#PBF | 功能描述:IC REG BST ADJ 0.1A/175MA 10MSOP 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 |
| LT1944-1EMS#TR | 功能描述:IC REG BST ADJ 0.1A/175MA 10MSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:升压（升压） 输出类型:可调式 输出数:1 输出电压:1.24 V ~ 30 V 输入电压:1.5 V ~ 12 V PWM 型:电流模式，混合 频率 - 开关:600kHz 电流 - 输出:500mA 同步整流器:无 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) 供应商设备封装:8-SOIC |
发布紧急采购，3分钟左右您将得到回复。