- 您现在的位置：买卖IC网 > PDF目录1829 > LTC3442EDE#TRPBF (Linear Technology)IC REG BUCK BOOST SYNC ADJ 12DFN PDF资料下载
参数资料
| 型号： | LTC3442EDE#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 9/20页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK BOOST SYNC ADJ 12DFN |
| 标准包装： | 2,500 |
| 类型： | 降压（降压），升压（升压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 2.4 V ~ 5.25 V |
| 输入电压： | 2.4 V ~ 5.5 V |
| PWM 型： | Burst Mode? |
| 频率 - 开关： | 300kHz ~ 2MHz |
| 电流 - 输出： | 1.2A |
| 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： | 12-WFDFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 12-DFN（4x3） |
LTC3442
OPERATION
Reverse Current Limit
During fixed frequency operation, the LTC3442 operates
in forced continuous conduction mode. The reverse cur-
rent limit amplifier monitors the inductor current from
the output through switch D. Once the negative inductor
current exceeds 500mA typical, the IC will shut off switch?D.
Four-Switch Control
Figure 1 shows a simplified diagram of how the four in-
ternal switches are connected to the inductor, V IN , V OUT
and GND. Figure 2 shows the regions of operation for the
LTC3442 as a function of the internal control voltage, V CI .
Depending on the control voltage, the IC will operate in
either buck, buck/boost or boost mode. The V CI voltage
is a level shifted voltage from the output of the error amp
(V C ) (see Figure 5). The four power switches are properly
phased so the transfer between operating modes is con-
tinuous, smooth and transparent to the user. When V IN
approaches V OUT the buck/boost region is reached where
the conduction time of the four switch region is typically
150ns. Referring to Figures 1 and 2, the various regions
of operation will now be described.
Buck Region (V IN > V OUT )
Switch D is always on and switch C is always off during
this mode. When the internal control voltage, V CI , is
above voltage V1, output A begins to switch. During the
off-time of switch A, synchronous switch B turns on for
the remainder of the time. Switches A and B will alternate
similar to a typical synchronous buck regulator. As the
control voltage increases, the duty cycle of switch A
increases until the maximum duty cycle of the converter
in buck mode reaches DMAX_BUCK, given by:
DMAX_BUCK = 100 – D4 SW %
where D4 SW = duty cycle % of the four switch range.
D4 SW = (150ns ? f ) ? 100 %
where f = operating frequency, Hz.
V IN
9
V OUT
8
Beyond this point the “four switch,” or buck/boost region
is reached.
88%
D MAX
BOOST
PMOS A PMOS D
SW1 SW2
4 6
NMOS B NMOS C
3442 F01
Figure 1. Simplified Diagram of Output Switches
V4 ( ≈2.05V)
Buck/Boost or Four Switch (V IN ~ V OUT )
When the internal control voltage, V CI , is above voltage
V2, switch pair AD remain on for duty cycle DMAX_BUCK,
and the switch pair AC begins to phase in. As switch pair
AC phases in, switch pair BD phases out accordingly.
When the V CI voltage 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
D4 SW . The input voltage, V IN , where the four switch region
begins is given by:
BOOST REGION
PWM AB SWITCHES BUCK REGION
V IN =
D MIN
BOOST
D MAX
BUCK
0%
DUTY
CYCLE
A ON, B OFF
PWM CD SWITCHES
D ON, C OFF
FOUR SWITCH PWM BUCK/BOOST REGION
3442 F02
V3 ( ≈1.65V)
V2 ( ≈1.55V)
V1 ( ≈0.9V)
INTERNAL
CONTROL
VOLTAGE, V CI
V OUT
1 – (150ns ? f)
The point at which the four switch region ends is given by:
V IN = V OUT (1 – D) = V OUT (1 – 150ns ? f) V
Figure 2. Switch Control vs Internal Control Voltage, V CI
3442fb
For more information www.linear.com/LTC3442
9
相关PDF资料 |
PDF描述 |
|---|---|
| LTC3443EDE#TRPBF | IC REG BUCK BOOST SYNC ADJ 12DFN |
| LTC3444EDD#TRPBF | IC DC/DC CONV WCDMA 8-DFN |
| LTC3447EDD#TRPBF | IC REG BUCK SYNC ADJ 0.6A 10DFN |
| LTC3448EMS8E#TRPBF | IC REG BUCK SYNC ADJ 0.6A 8MSOP |
| LTC3450EUD#TRPBF | IC CONV PS TRIPLE TFT/LCD 16QFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3443 | 制造商:LINER 制造商全称:Linear Technology 功能描述:High Current Micropower 600kHz Synchronous Buck-Boost DC/DC Converter |
| LTC3443EDE | 功能描述:IC REG BUCK BOOST SYNC ADJ 12DFN 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: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 |
| LTC3443EDE#PBF | 功能描述:IC REG BUCK BOOST SYNC ADJ 12DFN 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 |
| LTC3443EDE#TR | 功能描述:IC REG BUCK BOOST SYNC ADJ 12DFN 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: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 |
| LTC3443EDE#TRPBF | 功能描述:IC REG BUCK BOOST SYNC ADJ 12DFN 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 |
发布紧急采购，3分钟左右您将得到回复。