- 您现在的位置：买卖IC网 > PDF目录44988 > LTC1929IG-PG (LINEAR TECHNOLOGY CORP) 3 A DUAL SWITCHING CONTROLLER, 310 kHz SWITCHING FREQ-MAX, PDSO28 PDF资料下载
参数资料
| 型号： | LTC1929IG-PG |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 稳压器 |
| 英文描述： | 3 A DUAL SWITCHING CONTROLLER, 310 kHz SWITCHING FREQ-MAX, PDSO28 |
| 封装： | 0.209 INCH, PLASTIC, SSOP-28 |
| 文件页数： | 15/28页 |
| 文件大小： | 310K |
| 代理商： | LTC1929IG-PG |
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页当前第15页第16页第17页第18页第19页第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
22
LTC1929/LTC1929-PG
Design Example
As a design example, assume VIN=5V(nominal),VIN = 5.5V
(max), VOUT = 1.8V, IMAX = 20A, TA = 70°C and f = 300kHz.
The inductance value is chosen first based on a 30% ripple
current assumption. The highest value of ripple current
occurs at the maximum input voltage. Tie the FREQSET pin
to the INTVCC pin for 300kHz operation. The minimum
inductance for 30% ripple current is:
L
V
fI
V
kHz
A
V
H
OUT
IN
≥
()
≥ ()( )( )
≥
1
18
300
30
10
1
18
55
135
.
%
.
A 1.5
H inductor will produce 27% ripple current. The
peak inductor current will be the maximum DC value plus
one half the ripple current, or 11.4A. The minimum on-
time occurs at maximum VIN:
t
V
Vf
V
kHz
s
ON MIN
OUT
IN
() == ()(
)
=
18
5 5
300
11
.
The RSENSE resistors value can be calculated by using the
maximum current sense voltage specification with some
accomodation for tolerances:
R
mV
A
SENSE =≈
50
11 4
0 004
.
The power dissipation on the topside MOSFET can be
easily estimated. Using a Siliconix Si4420DY for example;
RDS(ON) = 0.013, CRSS = 300pF. At maximum input
voltage with TJ(estimated) = 110°C at an elevated ambient
temperature:
P
V
CC
VA
pF
kHz
W
MAIN =
() +() ° °
()
[]
+
() ( )( )
() =
18
55
10
1
0 005 110
25
0 013
1 7 5 5
10
300
0 65
2
.
..
.
The worst-case power disipated by the synchronous
MOSFET under normal operating conditions at elevated
ambient temperature and estimated 50
°C junction tem-
perature rise is:
P
VV
V
A
W
SYNC =
() ( )
()
=
55
18
55
10
1 48 0 013
129
2
..
.
..
.
A short-circuit to ground will result in a folded back current
of about:
I
mV
ns
V
H
A
SC =
+
()
=
25
0 004
1
2
200
5 5
15
66
.
The worst-case power disipated by the synchronous
MOSFET under short-circuit conditions at elevated ambi-
ent temperature and estimated 50
°C junction temperature
rise is:
P
VV
V
A
mW
SYNC =
() ( )
()
=
55
18
55
66
148 0 013
564
2
..
.
..
.
which is less than half of the normal, full-load dissipation.
Incidentally, since the load no longer dissipates power in
the shorted condition, total system power dissipation is
decreased by over 99%.
The duty factor for this application is:
DF
V
O
IN
==
=
18
5
036
.
Using Figure 4, the RMS ripple current will be:
IINRMS = (20A)(0.23) = 4.6ARMS
An input capacitor(s) with a 4.6ARMS ripple current rating
is required.
The output capacitor ripple current is calculated by using
the inductor ripple already calculated for each inductor
and multiplying by the factor obtained from Figure 3
along with the calculated duty factor. The output ripple in
APPLICATIO S I FOR ATIO
WU
U
相关PDF资料 |
PDF描述 |
|---|---|
| LTC203MJ/883B | QUAD 1-CHANNEL, SGL POLE SGL THROW SWITCH, CDIP16 |
| LTC202MJ/883B | QUAD 1-CHANNEL, SGL POLE SGL THROW SWITCH, CDIP16 |
| LTC201AMJ/883B | QUAD 1-CHANNEL, SGL POLE SGL THROW SWITCH, CDIP16 |
| LTC2904IDDB8 | 2-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 |
| LTC2905IDDB8#PBF | 2-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC1929IG-PG#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 28-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 |
| LTC1929IG-PG#TR | 功能描述:IC REG CTRLR BUCK PWM CM 28-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 |
| LTC1929IG-PG#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 28-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 |
| LTC1949ES8 | 制造商:Linear Technology 功能描述: |
| LTC1955EUH | 功能描述:IC INTERFACE DL SMART CARD 32QFN RoHS:否 类别:集成电路 (IC) >> 接口 - 控制器 系列:- 标准包装:2,450 系列:- 控制器类型:SPI 总线至 I²C 总线桥接 接口:I²C，串行，SPI 电源电压:2.4 V ~ 3.6 V 电流 - 电源:11mA 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:24-VFQFN 裸露焊盘 供应商设备封装:24-HVQFN（4x4） 包装:托盘 配用:568-3511-ND - DEMO BOARD SPI TO I2C 其它名称:935286452157SC18IS600IBSSC18IS600IBS-ND |
发布紧急采购，3分钟左右您将得到回复。