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参数资料
| 型号： | LTC3533EDE |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 稳压器 |
| 英文描述： | 7 A SWITCHING REGULATOR, 2000 kHz SWITCHING FREQ-MAX, PDSO14 |
| 封装： | 4 X 3 MM, 0.75 MM HEIGHT, PLASTIC, MO-229WGED-3, DFN-14 |
| 文件页数： | 16/16页 |
| 文件大小： | 313K |
| 代理商： | LTC3533EDE |
LTC3533
9
3533f
OPERATION
D4SW = (150ns f) 100 %
where f = operating frequency, Hz.
Beyond this point the “four switch,” or buck/boost region
is reached.
Buck/Boost or Four Switch (VIN ~ VOUT)
When the control voltage, VC, is above voltage V2, switch
pair AD remain on for duty cycle DMAX_BUCK, and switch
pair AC begins to phase in. As switch pair AC phases in,
switch pair BD phases out accordingly. When VC reaches
the edge of the buck/boost range, at voltage V3, the AC
switch pair completely phase out the BD pair, and the boost
phase begins at duty cycle D4SW. The input voltage, VIN,
where the four switch region begins is given by:
VIN = VOUT(1 – D) = VOUT(1 – 150ns f) V
The point at which the four switch region ends is given
by:
V
ns f
V
IN
OUT
=
1
150
( )
where f = operating frequency, Hz.
Boost Region (VIN < VOUT)
Switch A is always on and switch B is always off during
this mode. When the control voltage, VC, is above volt-
age V3, switch pair CD will alternately switch to provide
a boosted output voltage. This operation is typical to a
synchronous boost regulator. The maximum duty cycle
of the converter is limited to 90% typical and is reached
when VC is above V4.
BURST MODE OPERATION
Burst Mode operation reduces the LTC3533’s quiescent
current consumption at light loads and improves overall
conversion efciency, increasing battery life. During Burst
Mode operation the LTC3533 delivers energy to the out-
put until it is regulated and then goes into a sleep mode
where the outputs are off and the quiescent current drops
to 40A. In this mode the output ripple has a variable
frequency component that depends upon load current,
and will typically be about 2% peak-to-peak. Burst Mode
operation ripple can be reduced slightly by using more
output capacitance. Another method of reducing Burst
Mode operation ripple is to place a small feed-forward
capacitor across the upper resistor in the VOUT feedback
divider network (as in Type III compensation).
During the period where the device is delivering energy
to the output, the peak switch current will rise to 450mA
typical and the inductor current will terminate at zero cur-
rent for each cycle. In this mode, the typical maximum
average output currents are given by:
IMAX(BURST)BUCK ≈ 225mA; VOUT < VIN
IMAX(BURST)BOOST ≈ 225mA (VIN/VOUT); VOUT > VIN
IMAX(BURST)BUCK-BOOST ≈ 350mA; VOUT ≈ VIN, since the
input and output are connected together for most of the
cycle.
The efciency below 1mA becomes dominated primarily
by the quiescent current. The Burst Mode operation ef-
ciency is given by:
Efficiency
I
AI
LOAD
+
η
40
where
η is typically 90% during Burst Mode operation
Programmable Automatic Burst Mode Operation
Burst Mode operation can be automatic or digitally con-
trolled with a single pin. In automatic mode, the LTC3533
enters Burst Mode operation at the programmed threshold
and returns to xed frequency operation when the load
demand increases. The load current at which the mode
transition occurs is programmed using a single external
resistor from BURST to ground, according to the follow-
ing equations:
Enter Burst Mode Operation I
R
BURST
:
=
17
E
Exit Burst Mode Operation I
R
BURST
:
=
19
Where RBURST is in kΩ and IBURST is the load transition
current in Amps. Do not use values of RBURST greater
than 1M
Ω.
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相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3533EDE#PBF | 功能描述:IC REG BUCK BOOST SYNC ADJ 14DFN 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 |
| LTC3533EDE#PBF | 制造商:Linear Technology 功能描述:DC/DC Converter IC |
| LTC3533EDE#TRPBF | 功能描述:IC REG BUCK BOOST SYNC ADJ 14DFN 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 |
| LTC3533EDEPBF | 制造商:Linear Technology 功能描述:2A 1.8-5.5V Synch Buck-Boost DC/DC DFN14 |
| LTC3534 | 制造商:LINER 制造商全称:Linear Technology 功能描述:40V, 2A Synchronous Buck-Boost DC/DC |
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