參數(shù)資料
型號(hào)： LTC1702IGN
廠商： LINEAR TECHNOLOGY CORP
元件分類： 穩(wěn)壓器
英文描述： Dual 550kHz Synchronous 2-Phase Switching Regulator Controller
中文描述： 5 A DUAL SWITCHING CONTROLLER, 750 kHz SWITCHING FREQ-MAX, PDSO24
封裝： 0.150 INCH, PLASTIC, SSOP-24
文件頁(yè)數(shù)： 27/36頁(yè)
文件大?。?/td> 350K
代理商： LTC1702IGN
27
LTC1702
2-Step Efficiency Calculation
Calculating the efficiency of a 2-step converter system
involves some subtleties. Simply multiplying the effi-
ciency of the primary 5V or 3.3V supply by the efficiency
of the 1.8V or 1.5V supply underestimates the actual
efficiency, since a significant fraction of the total power is
drawn from the 3.3V and 5V rails in a typical system. The
correct way to calculate system efficiency is to calculate
the power lost in each stage of the converter, and divide the
total output power from all outputs by the sum of the
output power plus the power lost:
Efficiency
TotalOutputPower
TotalOutputPower
TotalPowerLost
+
=
(
)
100%
In our example 2-step system, the total output power is:
Total output power =
15W + 16.5W + 1.25W + 3.6W + 15W = 51.35W
corresponding to 5V, 3.3V, 2.5V, 1.8V and 1.5V output
voltages.
Assuming the LTC1702 provides 90% efficiency at each
output, the additional load on the 5V and 3.3V supplies is:
1.5V: 15W/90% = 16.6W/3.3V = 5A from 3.3V
1.8V: 3.6W/90% = 4W/5V = 0.8A from 5V
2.5V: 1.25W/75% = 1.66W/3.3V = 0.5A from 3.3V
If the 5V and 3.3V supplies are each 94% efficient, the
power lost in each supply is:
1.5V: 16.6W – 15W = 1.6W
1.8V: 4W – 3.6W = 0.4W
2.5V: 1.66W – 1.25W = 0.4W
3.3V: 17.55W – 16.5W = 1W
5V:
16W – 15W = 1W
Total loss = 4.4W
Total system efficiency =
51.35W/(51.35W + 4.4W) = 92.1%
APPLICATIO
S I
N
FOR
ATIO
U
W
U
Maximizing High Load Current Efficiency
Efficiency at high load currents (when the LTC1702 is
operating in continuous mode) is primarily controlled by
the resistance of the components in the power path
(QT, QB, L
EXT
) and power lost in the gate drive circuits due
to MOSFET gate charge. Maximizing efficiency in this
region of operation is as simple as minimizing these
terms.
The behavior of the load over time affects the efficiency
strategy. Parasitic resistances in the MOSFETs and the
inductor set the maximum output current the circuit can
supply without burning up. A typical efficiency curve
(Figure 15) shows that peak efficiency occurs near 30% of
this maximum current. If the load current will vary around
the efficiency peak and will spend relatively little time at the
maximum load, choosing components so that the average
load is at the efficiency peak is a good idea. This puts the
maximum load well beyond the efficiency peak, but usually
gives the greatest system efficiency over time, which
translates to the longest run time in a battery-powered
system. If the load is expected to be relatively constant at
the maximum level, the components should be chosen so
that this load lands at the peak efficiency point, well below
the maximum possible output of the converter.
Figure 15. Typical LTC1702 Efficiency Curves
LOAD CURRENT (A)
0
70
E
80
90
100
5
10
1702 G01
15
V
IN
= 5V
V
OUT
= 3.3V
V
OUT
= 2.5V
V
OUT
= 1.6V
相關(guān)PDF資料
PDF描述
LTC1706-85 VID Voltage Programmer for Intel VRM 8.5
LTC1706EMS-85 VID Voltage Programmer for Intel VRM 8.5
LTC1706CS8-19 VID Voltage Programmer
LTC1706C-19 Circular Connector; Body Material:Aluminum; Series:PT06; No. of Contacts:18; Connector Shell Size:14; Connecting Termination:Crimp; Circular Shell Style:Straight Plug; Circular Contact Gender:Pin; Insert Arrangement:14-18
LTC1706-19 VID Voltage Programmer
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC1702IGN#PBF 功能描述:IC REG CTRLR BUCK PWM VM 24-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:PolyPhase® 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX
LTC1702IGN#TR 功能描述:IC REG CTRLR BUCK PWM VM 24-SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:PolyPhase® 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX
LTC1702IGN#TRPBF 功能描述:IC REG CTRLR BUCK PWM VM 24-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:PolyPhase® 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX
LTC1703CG 功能描述:IC REG SW DUAL SYNC VID 28SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 標(biāo)準(zhǔn)包裝:43 系列:- 應(yīng)用:控制器，Intel VR11 輸入電壓:5 V ~ 12 V 輸出數(shù):1 輸出電壓:0.5 V ~ 1.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:48-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:48-QFN（7x7） 包裝:管件
LTC1703CG#PBF 功能描述:IC REG SW DUAL SYNC VID 28SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 標(biāo)準(zhǔn)包裝:2,000 系列:- 應(yīng)用:控制器，DSP 輸入電壓:4.5 V ~ 25 V 輸出數(shù):2 輸出電壓:最低可調(diào)至 1.2V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:30-TFSOP（0.173"，4.40mm 寬） 供應(yīng)商設(shè)備封裝:30-TSSOP 包裝:帶卷 (TR)
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*