参数资料
型号: LTC1434IGN
厂商: Linear Technology
文件页数: 10/20页
文件大小: 0K
描述: IC REG BUCK 3.3V/5V/ADJ 20SSOP
标准包装: 55
类型: 降压(降压)
输出类型: 两者兼有
输出数: 1
输出电压: 3.3V,5V,可调
输入电压: 3 V ~ 13.5 V
PWM 型: 电流模式
频率 - 开关: 最高 700kHz
电流 - 输出: 450mA
同步整流器:
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 20-SSOP(0.154",3.90mm 宽)
包装: 管件
供应商设备封装: 20-SSOP
LTC1433/LTC1434
APPLICATIO N S I N FOR M ATIO N
Efficiency Considerations
Since there are two separate pins for the drain of the small
and large P-channel switch, we could utilize two induc-
tors to further enhance the efficiency of the regulator over
the low load current range. Figure 4 shows the circuit
connection.(Also refer to the Typical Applications sec-
tion.)
Hence, the dual inductor configuration is good for the user
who requires as high an efficiency as possible at low load
while retaining constant frequency operation.
Output Voltage Programming
The LTC1433/LTC1434 family all have pin selectable out-
put voltage programming. The output voltage is selected
by the V PROG pin as follows:
BSW
LTC1433/
LTC1434
L1
D1
L2
V PROG = 0V
V PROG = V IN
V PROG = Open (DC)
V OUT = 3.3V
V OUT = 5V
V OUT = Adjustable
SSW
D2
1433/34 F04
Figure 4. Using Two Inductors for Higher Low Current Efficiency
To reduce core losses, the user can use a higher value
inductor on the small P-channel switch. Since this switch
only carries a small part of the overall current, the user can
still use a small physical size inductor without sacrificing
on copper losses. The Schottky diode can also be chosen
with a lower current rating. For the graph in Figure 5, a
Coilcraft DT1608C series inductor is used along with a
The LTC1433/LTC1434 family also has remote output
voltage sense capability. The top of the internal resistive
divider is internally connected to V OSENSE . For fixed output
voltage applications, the V OSENSE pin is connected to the
output voltage as shown in Figure 6 . When using an
external resistive divider, the V PROG pin is left open DC and
the V OSENSE pin is connected to the feedback resistors as
shown in Figure 7. To prevent stray pickup, a 100pF
capacitor is suggested across R1 located close to the
LTC1433/LTC1434.
MBRS0520LT3 Schottky diode on the SSW pin. As can be
seen from Figure 5, the average efficiency gain over the
region where the small P-channel is on is about 3%.
V PROG
LTC1433/ V OSENSE
LTC1434
GND: V OUT = 3.3V
V IN : V OUT = 5V
+
C OUT
V OUT
100
90
V OUT = 3.3V
C OSC = 47pF
V IN = 5V
SGND
1433/34 F06
Figure 6. LTC1433/LTC1434 Fixed Output Applications
80
70
V IN = 9V
V OUT
60
ONE 22 μ H INDUCTOR
V PROG
LTC1433/ V OSENSE
OPEN (DC)
R2
( )
V OUT = 1.19V 1 +
50
40
0.001
ON SSW AND BSW
100 μ H ON SSW
22 μ H ON BSW
0.01 0.1 1
LOAD CURRENT (A)
1433/34 ? F05
LTC1434
SGND
R2
R1
100pF
R1
1433/34 F07
Figure 5. Efficiency Comparison Between Single Inductor
and Dual Inductor
10
Figure 7. LTC1433/LTC1434 Adjustable Applications
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LTC1434IGN#PBF 功能描述:IC REG BUCK 3.3V/5V/ADJ 20SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压(升压) 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 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:SOT-23-5 细型,TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT
LTC1434IGN#TR 功能描述:IC REG BUCK 3.3V/5V/ADJ 20SSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压(升压) 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 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:SOT-23-5 细型,TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT
LTC1434IGN#TRPBF 功能描述:IC REG BUCK 3.3V/5V/ADJ 20SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压(升压) 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 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:SOT-23-5 细型,TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT
LTC1435ACG 功能描述:IC REG CTRLR BUCK PWM CM 16-SSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:4,500 系列:PowerWise® PWM 型:控制器 输出数:1 频率 - 最大:1MHz 占空比:95% 电源电压:2.8 V ~ 5.5 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 125°C 封装/外壳:6-WDFN 裸露焊盘 包装:带卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名称:LM1771SSDX
LTC1435ACG#PBF 功能描述:IC REG CTRLR BUCK PWM CM 16-SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,000 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:1MHz 占空比:50% 电源电压:9 V ~ 10 V 降压:无 升压:是 回扫:是 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 85°C 封装/外壳:8-TSSOP(0.173",4.40mm 宽) 包装:带卷 (TR)