参数资料
型号: LT1737IS#TRPBF
厂商: Linear Technology
文件页数: 21/28页
文件大小: 0K
描述: IC REG CTRLR FLYBK ISO CM 16SOIC
标准包装: 2,500
PWM 型: 电流模式
输出数: 1
频率 - 最大: 125kHz
占空比: 90%
电源电压: 4.1 V ~ 20 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 125°C
封装/外壳: 16-SOIC(0.154",3.90mm 宽)
包装: 带卷 (TR)
LT1737
TYPICAL APPLICATIO S
BASIC APPLICATION WITH
3-WINDING TRANSFORMER
Figure 8 shows a compact, low power application of the
LT1737. Transformer T1 is an off-the-shelf VERSA-PAC TM ,
#VP1-0190, produced by Coiltronics. As manufactured, it
consists of six ideally identical independent windings. In
this application, two windings are stacked in series on the
primary side and three are placed in parallel on the
secondary side. This arrangement provides a 2:1 primary-
to-secondary turns ratio while maximizing overall effi-
ciency. The remaining primary side winding provides a
ground-referred version of the flyback voltage waveform
for the purpose of feedback.
The design accepts an input voltage in the range of 8V to
25V and outputs an isolated 5V. To prevent overvoltage on
the LT1737 and the gate of MOSFET M1, an LT1121 low
dropout linear regulator is employed (U2). Resistor di-
vider R11/R12 sets the output of U2 at nominally 8.25V. (A
few hundred millivolts of dropout will therefore be seen at
the very bottom of the input supply range.) The positive
going drive potential at the LT1737 GATE pin is typically 2V
or so below its V CC supply pin, so a logic level MOSFET has
been specified for M1.
Capacitor C6 sets the switching frequency at approxi-
mately 200kHz. Optimal load compensation for the
transformer and secondary circuit components is set by
resistor R8. Resistor R10 provides a guaranteed mini-
mum load of about 20mA to maintain rough output voltage
regulation. The soft-start and UVLO features are unused
as shown.
VERSA-PAC is a trademark of Coiltronics, Inc.
6
T1
COILTRONICS
V IN
3
?
VP1-0190
D1
8 1 330 μ F
OUT
INP
35V
U2
LT1121
5%
C3
5%
2
R5
R6
R7
R8
47pF 0.1 μ F
5%
5%
5%
5%
NPO Z5U
R13
51 ?
5%
500mA
+
C2
10V
? 7 ? 8 ? 9
1 μ H
+
C8
OPTIONAL OUTPUT FILTER
R3
12.7k
1%
R4
3.92k
1%
8
7
C5
1nF
25V
X7R
+ C1
D2
R11 1N5250
24k
3 2
GND ADJ
R12 D3
20k 1 μ F MBR0540
25V
Z5U
9 10 15
3V OUT UVLO V CC
16
FB GATE
LT1737
V C I SENSE
OSCAP SFST t ON ENDLY MINENAB R OCMP R CMPC SGND PGND
6 3 14 13 12 4 5 11 1
C6 C7
51k 51k 51k 4.3k
50V 25V
1737 F08
R9
68 ?
5%
C4
470pF
50V
X7R
R2
5.1 ?
5%
C9
1nF
25V
X7R
1
4
2
5
?
?
MBRD330
10 11 12
IRLL014 10V
R1
0.2 ?
0.5W
IRC TYPE LR 2010
L1
R10
68 μ F 240 ?
5%
M1 33 μ F
V OUT
5V
V OUT
5V
500mA
C1: SANYO ALUMINUM ELECTROLYTIC (35CV331GX)
C2: SANYO POSCAP (10TPC68M)
C8: SANYO POSCAP (10TPA33M)
L1: COILCRAFT DO1608C-102 1 μ H, 0.05 ? INDUCTOR
M1: INT’L RECTIFIER IRLL014 60V, 0.2 ? LOGIC LEVEL N-CH MOSFET
U2: LINEAR TECHNOLOGY MICROPOWER LDO REGULATOR
D1: MOTOROLA 30V, 3A SCHOTTKY RECTIFIER
D2: 20V, 500mW ZENER DIODE
D3: MOTOROLA 40V, 0.5A SCHOTTKY RECTIFIER
Figure 8. 8V-25V to Isolated 5V Converter
1737fa
21
相关PDF资料
PDF描述
ASC06DRYN-S93 CONN EDGECARD 12POS DIP .100 SLD
MIC2198YML IC REG CTRLR BUCK PWM CM 12-MLF
SRP1235-R33M INDUCTOR 330NH 36.5A SMD
LTC3832-1ES8#TRPBF IC REG CTRLR BUCK PWM VM 8-SOIC
LTC3832-1ES8#TR IC REG CTRLR BUCK PWM VM 8-SOIC
相关代理商/技术参数
参数描述
LT1738 制造商:LINER 制造商全称:Linear Technology 功能描述:Slew Rate Controlled Ultralow Noise DC/DC Controller
LT1738EG 功能描述:IC REG CTRLR PWM CM 20-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:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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:24-WQFN 裸露焊盘 包装:带卷 (TR)
LT1738EG#PBF 功能描述:IC REG CTRLR PWM CM 20-SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 特色产品:LM3753/54 Scalable 2-Phase Synchronous Buck Controllers 标准包装:1 系列:PowerWise® PWM 型:电压模式 输出数:1 频率 - 最大:1MHz 占空比:81% 电源电压:4.5 V ~ 18 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:-5°C ~ 125°C 封装/外壳:32-WFQFN 裸露焊盘 包装:Digi-Reel® 产品目录页面:1303 (CN2011-ZH PDF) 其它名称:LM3754SQDKR
LT1738EG#TR 功能描述:IC REG CTRLR PWM CM 20-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:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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:24-WQFN 裸露焊盘 包装:带卷 (TR)
LT1738EG#TRPBF 功能描述:IC REG CTRLR PWM CM 20-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:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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:24-WQFN 裸露焊盘 包装:带卷 (TR)