参数资料
型号: LT3430EFE-1#TR
厂商: LINEAR TECHNOLOGY CORP
元件分类: 稳压器
英文描述: 6.5 A SWITCHING REGULATOR, 120 kHz SWITCHING FREQ-MAX, PDSO16
封装: 4.40 MM, PLASTIC, TSSOP-16
文件页数: 17/28页
文件大小: 321K
代理商: LT3430EFE-1#TR
LT3430/LT3430-1
24
34301fa
DUAL OUTPUT SEPIC CONVERTER
The circuit in Figure 14 generates both positive and negative
5V outputs with a single piece of magnetics. The two induc-
tors shown are actually just two windings on a standard
Coiltronics inductor. The topology for the 5V output is a
standard buck converter. The – 5V topology would be a
simple yback winding coupled to the buck converter if
C4 were not present. C4 creates a SEPIC (single-ended
primary inductance converter) topology which improves
regulation and reduces ripple current in L1. Without C4,
the voltage swing on L1B compared to L1A would vary
due to relative loading and coupling losses. C4 provides a
low impedance path to maintain an equal voltage swing in
L1B, improving regulation. In a yback converter, during
switch on time, all the converter’s energy is stored in L1A
only, since no current ows in L1B. At switch off, energy
is transferred by magnetic coupling into L1B, powering
the –5V rail. C4 pulls L1B positive during switch on time,
causing current to ow, and energy to build in L1B and
C4. At switch off, the energy stored in both L1B and C4
supply the –5V rail. This reduces the current in L1A and
changes L1B current waveform from square to triangular.
For details on this circuit, including maximum output cur-
rents, see Design Note 100.
POSITIVE-TO-NEGATIVE CONVERTER
The circuit in Figure 15 is a positive-to-negative topology
using a grounded inductor. It differs from the standard
approach in the way the IC chip derives its feedback
signal because the LT3430/LT3430-1 accepts only posi-
tive feedback signals. The ground pin must be tied to the
regulated negative output. A resistor divider to the FB pin
then provides the proper feedback voltage for the chip.
The following equation can be used to calculate maximum
load current for the positive-to-negative converter:
I
VV
f L
VV
MAX
P
IN
OUT
IN
OUT
IN
OUT
IN
OUT
F
=
+
++
()(
)
()( )( )
()(
– .
)
(– .
)(
)
2
015
IP = Maximum rated switch current
VIN = Minimum input voltage
VOUT = Output voltage
VF = Catch diode forward voltage
0.15 = Switch voltage drop at 3A
Example: with VIN(MIN) = 5.5V, VOUT = 12V, L = 10H,
VF = 0.52V, IP = 3A: IMAX = 0.6A.
VOUT
5V
VOUT
–5V
* L1 IS A SINGLE CORE WITH TWO WINDINGS
COILTRONICS #CTX25-4A
IF LOAD CAN GO TO ZERO, AN OPTIONAL
PRELOAD OF 1k TO 5k MAY BE USED TO
IMPROVE LOAD REGULATION
D1, D3: 30BQ060
VIN
7.5V TO 60V
GND
3430 F14
C2
0.68
F
CF
220pF
D1
C1
100
F
10V TANT
C5
100
F
10V TANT
C3
4.7
F
100V
CERAMIC
C4
100
F
10V
TANT
D2
MMSD914TI
D3
L1A*
25
H
L1B*
R1
15.4k
R2
4.99k
+
RC
3.3k
CC
0.022
F
BOOST
VIN
LT3430
SHDN
SYNC
SW
FB
VC
GND
APPLICATIONS INFORMATION
Figure 14. Dual Output SEPIC Converter
相关PDF资料
PDF描述
LT3430IFE-1 6.5 A SWITCHING REGULATOR, 120 kHz SWITCHING FREQ-MAX, PDSO16
LT3430EFE-1 6.5 A SWITCHING REGULATOR, 120 kHz SWITCHING FREQ-MAX, PDSO16
LT3467AIDDB#PBF 2.5 A SWITCHING REGULATOR, 2700 kHz SWITCHING FREQ-MAX, PDSO8
LT3467AIDDB 2.5 A SWITCHING REGULATOR, 2700 kHz SWITCHING FREQ-MAX, PDSO8
LT3467IS6#TRM 2.5 A SWITCHING REGULATOR, 1600 kHz SWITCHING FREQ-MAX, PDSO6
相关代理商/技术参数
参数描述
LT3430EFEPBF 制造商:Linear Technology 功能描述:LT3430 adj 3A Buck SD dc-dc converter
LT3430IFE 功能描述:IC REG BUCK ADJ 3A 16TSSOP 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
LT3430IFE#PBF 功能描述:IC REG BUCK ADJ 3A 16TSSOP 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
LT3430IFE#PBF 制造商:Linear Technology 功能描述:DC/DC Converter IC
LT3430IFE#TR 功能描述:IC REG BUCK ADJ 3A 16TSSOP 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