- 您现在的位置：买卖IC网 > PDF目录16307 > LTC3559EUD#PBF (Linear Technology)IC USB CHARGER 16-QFN PDF资料下载
参数资料
| 型号： | LTC3559EUD#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 18/24页 |
| 文件大小： | 0K |
| 描述： | IC USB CHARGER 16-QFN |
| 标准包装： | 121 |
| 功能： | 充电管理 |
| 电池化学： | 锂离子（Li-Ion）、锂聚合物（Li-Pol） |
| 电源电压： | 4.3 V ~ 5.5 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 16-WFQFN 裸露焊盘 |
| 供应商设备封装： | 16-QFN-EP（3x3） |
| 包装： | 管件 |
| 产品目录页面： | 1341 (CN2011-ZH PDF) |
LTC3559/LTC3559-1
APPLICATIONS INFORMATION
Average, rather than instantaneous, battery current may be
of interest to the user. For example, if a switching power
supply operating in low-current mode is connected in
parallel with the battery, the average current being pulled
out of the BAT pin is typically of more interest than the
instantaneous current pulses. In such a case, a simple RC
?lter can be used on the PROG pin to measure the average
battery current as shown in Figure 6. A 10k resistor has
been added between the PROG pin and the ?lter capacitor
to ensure stability.
LTC3559/
the current from building up in the cable too fast thus
dampening out any resonant overshoot.
Buck Switching Regulator General Information
The LTC3559/LTC3559-1 contain two 2.25MHz constant-
frequency current mode switching regulators that provide
up to 400mA each. Both switchers can be programmed
for a minimum output voltage of 0.8V and can be used
to power a microcontroller core, microcontroller I/O,
memory or other logic circuitry. Both regulators support
100% duty cycle operation (dropout mode) when the
input voltage drops very close to the output voltage and
LTC3559-1
PROG
GND
10k
R PROG
C FILTER
CHARGE
CURRENT
MONITOR
CIRCUITRY
are also capable of operating in Burst Mode operation for
highest ef?ciencies at light loads (Burst Mode operation
is pin selectable). The switching regulators also include
3559 F06
Figure 6. Isolated Capacitive Load on PROG Pin and Filtering
USB Inrush Limiting
When a USB cable is plugged into a portable product,
the inductance of the cable and the high-Q ceramic input
capacitor form an L-C resonant circuit. If there is not
much impedance in the cable, it is possible for the voltage
at the input of the product to reach as high as twice the
USB voltage (~10V) before it settles out. In fact, due to
the high voltage coef?cient of many ceramic capacitors
(a nonlinearity), the voltage may even exceed twice the
USB voltage. To prevent excessive voltage from damaging
the LTC3559/LTC3559-1 during a hot insertion, the soft
connect circuit in Figure 7 can be employed.
In the circuit of Figure 7, capacitor C1 holds MP1 off when
the cable is ?rst connected. Eventually C1 begins to charge
up to the USB voltage applying increasing gate support
to MP1. The long time constant of R1 and C1 prevents
MP1
soft-start to limit inrush current when powering on, short
circuit current protection, and switch node slew limiting
circuitry to reduce radiated EMI.
A single MODE pin sets both regulators in Burst Mode
operation or pulse skip operating mode while each regula-
tor is enabled individually through their respective enable
pins EN1 and EN2. The buck regulators input supply (PV IN )
should be connected to the battery pin (BAT). This allows
the undervoltage lockout circuit on the BAT pin to disable
the buck regulators when the BAT voltage drops below
2.45V. Do not drive the buck switching regulators from
a voltage other than BAT. A 2.2μF decoupling capacitor
from the PV IN pin to GND is recommended.
Buck Switching Regulator
Output Voltage Programming
Both switching regulators can be programmed for output
voltages greater than 0.8V. The output voltage for each
buck switching regulator is programmed using a resistor
divider from the switching regulator output connected to
the feedback pins (FB1 and FB2) such that:
C1
Si2333
V CC
V OUT = 0.8(1 + R1/R2)
5V USB
INPUT
USB CABLE
100nF
R1
C2
10μF
LTC3559/
LTC3559-1
Typical values for R1 are in the range of 40k to 1M. The
capacitor C FB cancels the pole created by feedback re-
40k
Figure 7. USB Soft Connect Circuit
GND
3559 F07
sistors and the input capacitance of the FB pin and also
helps to improve transient response for output voltages
much greater than 0.8V. A variety of capacitor sizes can
be used for C FB but a value of 10pF is recommended for
3559fb
18
相关PDF资料 |
PDF描述 |
|---|---|
| CM453232-3R9KL | INDUCTOR CHIP 3.9UH 10% 1812 SMD |
| VE-J1N-EZ-F4 | CONVERTER MOD DC/DC 18.5V 25W |
| CM453232-2R7KL | INDUCTOR CHIP 2.7UH 10% 1812 SMD |
| CM453232-1R8KL | INDUCTOR CHIP 1.8UH 10% 1812 SMD |
| CM453232-1R2KL | INDUCTOR CHIP 1.2UH 10% 1812 SMD |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3559EUD-TRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Linear USB Battery Charger with Dual Buck Regulators |
| LTC3560 | 制造商:LINER 制造商全称:Linear Technology 功能描述:2.25MHz, 800mA Synchronous Step-Down Regulator in ThinSOT |
| LTC3560E | 制造商:LINER 制造商全称:Linear Technology 功能描述:2.25MHz, 800mA Synchronous Step-Down Regulator in ThinSOT |
| LTC3560ES6 | 制造商:LINER 制造商全称:Linear Technology 功能描述:2.25MHz, 800mA Synchronous Step-Down Regulator in ThinSOT |
| LTC3560ES6#PBF | 制造商:Linear Technology 功能描述:2.1 A SWITCHING REGULATOR, 2700 kHz SWITCHING FREQ-MAX, PDSO6 |
发布紧急采购，3分钟左右您将得到回复。