- 您现在的位置：买卖IC网 > PDF目录15303 > LTC3778EF#TR (Linear Technology)IC REG CTRLR BUCK PWM CM 20TSSOP PDF资料下载
参数资料
| 型号： | LTC3778EF#TR |
| 厂商： | Linear Technology |
| 文件页数： | 18/24页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 20TSSOP |
| 标准包装： | 2,500 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 电源电压： | 4 V ~ 36 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： | 20-TSSOP（0.173"，4.40mm 宽） |
| 包装： | 带卷 (TR) |
| 其它名称： | LTC3778EFTR |
LTC3778
APPLICATIO S I FOR ATIO
C SS
0.1 μ F
R3
11k
R4
39k
1
2
R PG
100k 3
LTC3778
RUN/SS BOOST
VON TG
PGOOD SW
20
19
18
D B
CMDSH-3
C B
0.22 μ F
M1
Si4884
L1, 1.8 μ H
C IN
10 μ F
35V
× 3
V IN
5V TO 28V
V OUT
2.5V
10A
C C1
500pF
R C
20k
C C2
4
5
6
V RNG
I TH
FCB
SENSE +
SENSE –
PGND
17
16
15
M2
Si4874
D1
B340A
+
C OUT1-2
180 μ F
4V
× 2
C OUT3
22 μ F
6.3V
X7R
100pF
7
SGND
BG
14
C ON , 0.01 μ F
R1
8
I ON
DRV CC
13
C VCC
4.7 μ F
12.7k
R2
40.2k
R ON
400k
9
10
V FB
EXTV CC
INTV CC
V IN
12
11
R F
1 ?
C F
0.1 μ F
3778 F07
C IN : UNITED CHEMICON THCR60EIHI06ZT
C OUT1-2 : CORNELL DUBILIER ESRE181E04B
L1: SUMIDA CEP125-1R8MC-H
Figure 7. Design Example: 2.5V/10A at 250kHz
(
)
± 20 A ? ? 0 . 015 ? = ± 50 mV = 100 mV
Active Voltage Positioning
Active voltage positioning (also termed load “deregula-
tion” or droop) describes a technique where the output
voltage varies with load in a controlled manner. It is useful
in applications where rapid load steps are the main cause
of error in the output voltage. By positioning the output
voltage at or above the regulation point at zero load, and
below the regulation point at full load, one can use more
of the error budget for the load step. This allows one to
reduce the number of output capacitors by relaxing the
ESR requirement.
For example, in a 20A application, six 0.015 ? capacitors
are required in parallel to keep the output voltage within a
100mV tolerance:
? 1 ?
? 6 ?
Using active voltage positioning, the same specification
can be met with only three capacitors. In this case, the load
step will cause an output voltage change of:
By positioning the output voltage at the regulation point at
no load, it will drop 100mV below the regulation point after
the load step. However, when the load disappears or the
output is stepped from 20A to 0A, the 100mV is recovered.
This way, a total of 100mV change is observed on V OUT in
all conditions, whereas a total of ± 100mV or 200mV is
seen on V OUT without voltage positioning while using only
three output capacitors.
Implementing active voltage positioning requires setting a
precise gain between the sensed current and the output
voltage. Because of the variability of MOSFET on-resis-
tance, it is prudent to use a sense resistor with active
voltage positioning. In order to minimize power lost in this
resistor, a low value of 0.002 ? is chosen. The nominal
sense voltage will now be:
V SNS(NOM) = (0.002 ? )(20A) = 40mV
To maintain a reasonable current limit, the voltage on the
V RNG pin is reduced to 0.5V by connecting it to a resistor
divider from INTV CC , corresponding to a 50mV nominal
sense voltage.
Next, the gain of the LTC3778 error amplifier must be
( ) (
)
= 20 A ? ? 0 . 015 ? = 100 mV
? V OUT ( STEP )
18
? 1 ?
? 3 ?
determined. The change in I TH voltage for a corresponding
change in the output current is:
3778f
相关PDF资料 |
PDF描述 |
|---|---|
| VE-JW4-EY-F4 | CONVERTER MOD DC/DC 48V 50W |
| VI-JWB-EW-F1 | CONVERTER MOD DC/DC 95V 100W |
| H2BXT-10112-B8-ND | JUMPER-H1500TR/A3048B/X 12" |
| ESC19DREI-S93 | CONN EDGECARD 38POS .100 EYELET |
| TVX2G4R7MCD | CAP ALUM 4.7UF 400V 20% AXIAL |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3780EG | 制造商:Linear Technology 功能描述:DC DC Cntrlr Dual-OUT Synchronous Boost/Buck Controller 4V to 36V Input 24-Pin SSOP |
| LTC3780EG#PBF | 功能描述:IC REG CTRLR BST 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:- 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 |
| LTC3780EG#TR | 制造商:Linear Technology 功能描述:DC DC Cntrlr Dual-OUT Synchronous Boost/Buck Controller 4V to 36V Input 24-Pin SSOP T/R |
| LTC3780EG#TRPBF | 功能描述:IC REG CTRLR BST 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 |
| LTC3780EGPBF | 制造商:Linear Technology 功能描述:4-Switch Buck-Boost Controller SSOP24 |
发布紧急采购，3分钟左右您将得到回复。