参数资料
型号: LT1766EGN
厂商: Linear Technology
文件页数: 25/30页
文件大小: 0K
描述: IC REG BUCK ADJ 1.5A 16SSOP
标准包装: 100
类型: 降压(降压)
输出类型: 可调式
输出数: 1
输出电压: 1.2 V ~ 54 V
输入电压: 5.5 V ~ 60 V
PWM 型: 电流模式
频率 - 开关: 200kHz
电流 - 输出: 1.5A
同步整流器:
工作温度: -40°C ~ 125°C
安装类型: 表面贴装
封装/外壳: 16-SSOP(0.154",3.90mm 宽)
包装: 管件
供应商设备封装: 16-SSOP
LT1766/LT1766-5
APPLICATIONS INFORMATION
RiseTime =
( )( 4 R C SS )( V OUT )
V BE
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
( )( ) 9 – ( 5 ) = 5 ms
47 ? 10 15 ? 10
Using the values shown in Figure 10,
3
Rise Time =
0 . 7
The ramp is linear and rise times in the order of 100ms are
possible. Since the circuit is voltage controlled, the ramp
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.
D2
1N4148W
INPUT
C2
40V
L1
0.33μF
47μH
+
D1
2.2μF
50V
CER
V C
SYNC GND
C F
15nF
220pF Q1
47k
V IN
SW
V IN
FB
CER
+
IF LOAD CAN GO TO ZERO, AN OPTIONAL
rate is unaffected by load characteristics and maximum
output current is unchanged. Variants of this circuit can
be used for sequencing multiple regulator outputs.
D2
1N4148W
OUTPUT
5V
1A
BOOST BIAS
V IN SW
C3
C1
LT1766 100μF R1
15.4k
SHDN FB
R2
4.99k
C SS
R3
R C 2k
2.2k
1766 F13
C C R4
0.022μF
C2
0.33μF
BOOST
7.5V
TO 60V
LT1766
SHDN
C3
2.2μF SYNC
100V
GND V C
R C C F
2.2k 220pF
C C
0.022μF
GND
C4
100μF
10V
TANT
* L1 IS A SINGLE CORE WITH TWO WINDINGS
COILTRONICS #CTX50-3A
?
PRELOAD OF 1k TO 5k MAY BE USED TO
IMPROVE LOAD REGULATION
D1, D3: 10MQ060N
L1A*
50μH
R1
15.4k
R2
4.99k
D1
C5
L1B* 100μF
10V
TANT
D3
+
+
V OUT1
5V
(SEE DN100
FOR MAX I OUT )
C1
100μF
10V
TANT
V OUT2
1766 F14 –5V ?
? I P – 2 ( V ? ( V OUT IN – 0 . 3 )
+ V
? OUT IN )( f )( L ) ?
+ V – 0 . 3 )( V
+ V
Figure 13. Buck Converter with Adjustable Soft-Start
DUAL OUTPUT SEPIC CONVERTER
The circuit in Figure 14 generates both positive and nega-
tive 5V outputs with a single piece of magnetics. The two
inductors shown are actually just two windings on a stan-
dard 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
Figure 14. Dual Output SEPIC Converter
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 LT1766 accepts only positive 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:
? ( V IN )( V OUT ) ?
)( V
I MAX =
( V OUT IN OUT F )
only, since no current ?ows in L1B. At switch off, energy
1766fc
25
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LT1766EGN#PBF 功能描述:IC REG BUCK ADJ 1.5A 16SSOP 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
LT1766EGN#TR 功能描述:IC REG BUCK ADJ 1.5A 16SSOP 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
LT1766EGN#TRPBF 功能描述:IC REG BUCK ADJ 1.5A 16SSOP 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
LT1766EGN-5 功能描述:IC REG BUCK 5V 1.5A 16SSOP 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
LT1766EGN-5#PBF 功能描述:IC REG BUCK 5V 1.5A 16SSOP 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