- 您现在的位置：买卖IC网 > PDF目录15243 > LTC1436AIGN-PLL (Linear Technology)IC REG CTRLR BUCK PWM CM 24-SSOP PDF资料下载
参数资料
| 型号： | LTC1436AIGN-PLL |
| 厂商： | Linear Technology |
| 文件页数： | 20/28页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 24-SSOP |
| 标准包装： | 55 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 138kHz |
| 占空比： | 99% |
| 电源电压： | 3.5 V ~ 30 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 ~ 85°C |
| 封装/外壳： | 24-SSOP（0.154"，3.90mm 宽） |
| 包装： | 管件 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页当前第20页第21页第22页第23页第24页第25页第26页第27页第28页
LTC1436A
LTC1436-PLL-A/LTC1437A
APPLICATIO N S I N FOR M ATIO N
1:N
SECONDARY WINDING
The minimum on-time for the LTC1436A/LTC1437A in a
properly configured application is less than 300ns but
+
V SEC
R6
LTC1436A
LTC1437A AUXDR
V OAUX
12V
increases at low ripple current amplitudes (see Figure 12).
If an application is expected to operate close to the
minimum on-time limit, an inductor value must be chosen
R5
SFB
AUXFB
AUXON
ON/OFF
+
10 μ F
that is low enough to provide sufficient ripple amplitude to
meet the minimum on-time requirement. To determine the
( )
V SEC = 1.19V 1 +
R6
R5
> 13V
1436 F11a
proper value, use the following procedure:
1. Calculate on-time at maximum supply, t ON(MIN) =
( )
V OAUX = 1.19V 1 +
V SEC
V OAUX
R6
R8
+
10 μ F
ON/OFF
AUXON
( )
V SEC = 1.19V 1 +
? I L ( MIN )
4. L MAX = t ON ( MIN ) ? ?
Figure 11a. 12V Output Auxiliary Regulator Using
Internal Feedback Resistors
1:N SECONDARY WINDING
LTC1436A
LTC1437A
AUXDR
+
SFB AUXFB
R5 R7
R6
R5
Figure 11b. 5V Output Auxiliary Regulator Using
External Feedback Resistors
R8
R7
1436 F11b
(1/f)(V OUT /V IN(MAX) ).
2. Use Figure 12 to obtain the peak-to-peak inductor ripple
current as a percentage of I MAX necessary to achieve
the calculated t ON(MIN) .
3. Ripple amplitude ? I L(MIN) = (% from Figure 12) (I MAX )
where I MAX = 0.1/R SENSE .
? V IN ( MAX ) – V OUT ?
? ?
Choose an inductor less than or equal to the calculated
L MAX to ensure proper operation.
400
V PULL-UP < 8.5V
350
ON/OFF
INPUT
AUXON
AUXFB
–
+
LTC1436A
LTC1437A
AUXDR
OUTPUT
300
RECOMMENDED
REGION FOR MIN
ON-TIME AND
MAX EFFICIENCY
1.19V REFERENCE
1436 F11c
250
Figure 11c. Auxiliary Comparator Configuration
Minimum On-Time Considerations
200
0
10 20 30 40 50 60 70
INDUCTOR RIPPLE CURRENT (% OF I MAX )
Minimum on-time, t ON(MIN) , is the smallest amount of
time that the LTC1436A/LTC1437A are capable of turning
the top MOSFET on and off again. It is determined by
internal timing delays and the gate charge required to turn
on the top MOSFET. Low duty cycle applications may
approach this minimum on-time limit. If the duty cycle
falls below what can be accommodated by the minimum
on-time, the LTC1436A/LTC1437A will begin to skip cycles.
The output voltage will continue to be regulated, but the
ripple current and ripple voltage will increase. Therefore
this limit should be avoided.
1435A F12
Figure 12. Minimum On-Time vs Inductor Ripple Current
Because of the sensitivity of the LTC1436A/LTC1437A
current comparator when operating close to the minimum
on-time limit, it is important to prevent stray magnetic flux
generated by the inductor from inducing noise on the
current sense resistor, which may occur when axial type
cores are used. By orienting the sense resistor on the
radial axis of the inductor (see Figure 13), this noise will be
minimized.
14367afb
20
相关PDF资料 |
PDF描述 |
|---|---|
| VE-J7H-EY-F4 | CONVERTER MOD DC/DC 52V 50W |
| VE-J7H-EY-F3 | CONVERTER MOD DC/DC 52V 50W |
| LTC1436AIGN#PBF | IC REG CTRLR BUCK PWM CM 24-SSOP |
| VE-J7H-EY-F2 | CONVERTER MOD DC/DC 52V 50W |
| VE-J74-EY-F4 | CONVERTER MOD DC/DC 48V 50W |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC1436AIGN-PLL#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 24-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: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 |
| LTC1436AIGN-PLL#TR | 功能描述:IC REG CTRLR BUCK PWM CM 24-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 |
| LTC1436AIGN-PLL#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 24-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: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 |
| LTC1436CGN | 功能描述:IC REG CTRLR BUCK PWM CM 24-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 |
| LTC1436CGN#PBF | 制造商:Linear Technology 功能描述:Step-Down Switching Regulators |
发布紧急采购，3分钟左右您将得到回复。