参数资料
| 型号： | LTC3561EDD#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 12/16页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC ADJ 1A 8DFN |
| 标准包装： | 2,500 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 0.8 V ~ 5 V |
| 输入电压： | 2.63 V ~ 5.5 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 最高 4MHz |
| 电流 - 输出： | 1A |
| 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： | 8-WFDFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 8-DFN-EP（3x3） |
LTC3561
APPLICATIO S I FOR ATIO
For cost reasons, a ceramic capacitor will be used. C OUT
selection is then based on load step droop instead of ESR
requirements. For a 5% output droop:
graphically in the layout diagram of Figure 5. Check
the following in your layout:
1. Does the capacitor C IN connect to the power V IN (Pin 5)
C OUT ≈ 2 . 5
1 A
1 MHz ? ( 5 % ? 2 . 5 V )
= 20 μ F
and power GND (Pin 4) as close as possible? This
capacitor provides the AC current to the internal power
MOSFETs and their drivers.
The closest standard value is 22 μ F. Since the output
impedance of a Li-Ion battery is very low, C IN is typically
10 μ F. In noisy environments, decoupling SV IN from PV IN
with an R6/C8 filter of 1 ? /0.1 μ F may help, but is typically
not needed.
The output voltage can now be programmed by choosing
the values of R1 and R2. To maintain high efficiency, the
current in these resistors should be kept small. Choosing
2 μ A with the 0.8V feedback voltage makes R1~400k. A
close standard 1% resistor is 412k and R2 is then 887k.
The compensation should be optimized for these compo-
nents by examining the load step response but a good
place to start for the LTC3561 is with a 13k ? and 1000pF
filter. The output capacitor may need to be increased
depending on the actual undershoot during a load step.
The circuit in Figure 6 shows the complete schematic for
this design example.
Board Layout Considerations
When laying out the printed circuit board, the follow-
ing checklist should be used to ensure proper oper-
ation of the LTC3561. These items are also illustrated
C IN
V IN
2. Are the C OUT and L1 closely connected? The (–) plate of
C OUT returns current to PGND and the (–) plate of C IN .
3. The resistor divider, R1 and R2, must be connected
between the (+) plate of C OUT and a ground line termi-
nated near SGND (Pin 2). The feedback signal V FB
should be routed away from noisy components and
traces, such as the SW line (Pin 3), and its trace should
be minimized.
4. Keep sensitive components away from the SW pin. The
input capacitor C IN , the compensation capacitor C C and
C ITH and all the resistors R1, R2, R T , and R C should be
routed away from the SW trace and the inductor L1.
5. A ground plane is preferred, but if not available, keep the
signal and power grounds segregated with small signal
components returning to the SGND pin at one point
which is then connected to the PGND pin.
6. Flood all unused areas on all layers with copper.
Flooding with copper will reduce the temperature rise of
power components. These copper areas should be
connected to one of the input supplies: PV IN , PGND,
SV IN or SGND.
PV IN
PGND
L1
C OUT
SV IN
V FB
LTC3561
SW
SGND
V OUT
C4
I TH
SHDN/R T
R2
R1
R3
R T
C3
3561 F06
BOLD LINES INDICATE HIGH CURRENT PATHS
Figure 5. LTC3561 Layout Diagram (See Board Layout Checklist)
3561f
12
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| LTC3562 | 制造商:LINER 制造商全称:Linear Technology 功能描述:I2C Quad Synchronous Step-Down DC/DC Regulator 2 × 600mA, 2 × 400mA |
| LTC3562EUD#PBF | 功能描述:IC REG BUCK SYNC ADJ QUAD 20QFN 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:2,500 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V，1.5V，1.8V，2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽）裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘 |
| LTC3562EUD#TRPBF | 功能描述:IC REG BUCK SYNC ADJ QUAD 20QFN 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:2,500 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V，1.5V，1.8V，2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽）裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘 |
| LTC3562EUD-PBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:I2C Quad Synchronous Step-Down DC/DC Regulator 2 × 600mA, 2 × 400mA |
| LTC3562EUD-TRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:I2C Quad Synchronous Step-Down DC/DC Regulator 2 × 600mA, 2 × 400mA |
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