参数资料
型号: LT3510IFE#TRPBF
厂商: Linear Technology
文件页数: 12/30页
文件大小: 0K
描述: IC REG BUCK ADJ 2A DL 20TSSOP
标准包装: 2,500
类型: 降压(降压)
输出类型: 可调式
输出数: 2
输出电压: 0.8 V ~ 23.8 V
输入电压: 3.1 V ~ 25 V
PWM 型: 电流模式
频率 - 开关: 250kHz ~ 1.5MHz
电流 - 输出: 2A
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: 20-TSSOP(0.173",4.40mm 宽)裸露焊盘
包装: 带卷 (TR)
供应商设备封装: 20-TSSOP-EP
LT3510
APPLICATIONS INFORMATION
Choosing the Output Voltage
1600
190
R1 = R2 ? ? OUT – 1 ?
Theoutputvoltageisprogrammedwitharesistordivider
between the output and the FB pin. Choose the 1% resis-
tors according to:
? V ?
? 0.8V ?
R2 should be 10k or less to avoid bias current errors. Refer-
1400
1200
1000
800
600
400
200
FREQUENCY
PHASE
185
180
175
170
165
160
155
ence designators refer to the Block Diagram in Figure 1.
100
0
20
40
60 80 100
120
140
150
Choosing the Switching Frequency
RESISTANCE (kΩ)
3510 F02
Max Frequency =
3.3 + 0.6 1
The LT3510 switching frequency is set by resistor R3 in
Figure 1. The R T /SYNC pin is internally regulated at 0.975V.
Setting resistor R3 sets the current in the R T /SYNC pin
which determines the oscillator frequency as illustrated
in Figure 2.
The switching frequency is typically set as high as pos-
sible to reduce overall solution size. The LT3510 employs
techniques to enhance dropout at high frequencies but
ef?ciency and maximum input voltage decrease due to
switching losses and minimum switch on times. The
maximum recommended frequency can be approximated
by the equation:
Figure 2. Frequency and Phase vs R T /SYNC Resistance
The following example along with the data in Table 1
illustrates the tradeoffs of switch frequency selection.
Example.
V IN = 25V, V OUT = 3.3V, I OUT = 2.5A,
Temperature = 0°C to 85°C
t ON(MIN) = 200ns (85°C from the Typical Performance
Characteristics graph), V D = 0.6V, V SW = 0.4V (85°C)
? ~ 750 kHz
25 – 0.4 + 0.6 200e-9
V OUT + V D 1
V IN – V SW + V D t ON(MIN)
Frequency (Hz)=
?
R T /SYNC ~ 42k (Figure 2)
Input Voltage Range
where V D is the forward voltage drop of the catch diode (D1
Figure 2), V SW is the voltage drop of the internal switch,
and t ON(MIN) in the minimum on time of the switch, all at
maximum load current.
Once the switching frequency has been determined, the
input voltage range of the regulator can be determined.
The minimum input voltage is determined by either the
LT3510’s minimum operating voltage of ~2.8V, or by its
Table 1. Ef?ciency and Size Comparisons for Different R RT/SYNC Values. 3.3V
Output
FREQUENCY R T /SYNC
EFFICIENCY
V VIN1/2 = 12V V IN(MAX)?
L* C* L + C AREA
1.2MHz 20.5k 79.0% 16 1.5μH 22μF 63mm 2
1.0MHz 26.7k 80.9% 18 2.2μH 47μF 66mm 2
750kHz 38.3k 81.2% 22 3.3μH 47μF 66mm 2
500kHz 61.9k 82.0% 24 4.7μH 47μF 66mm 2
250kHz 133k 83.9% 24 10μH 100μF 172mm 2
? V
IN(MAX) is de?ned as the highest input voltage that maintains constant output voltage ripple.
*Inductor and capacitor values chosen for stability and constant ripple current.
3510fe
12
相关PDF资料
PDF描述
LT3511MPMS#PBF IC REG FLYBK ISO ADJ .24A 16MSOP
LT3512MPMS#TRPBF IC REG FLYBK ISO ADJ .42A 16MSOP
LT3513IUHF#PBF IC REG 5-OUT FOR TFT-LCD 38QFN
LT3571IUD#TRPBF IC REG BOOST ADJ 0.47A 16QFN
LT3573IMSE#TRPBF IC REG FLYBACK ISO ADJ 16MSOP
相关代理商/技术参数
参数描述
LT3511 制造商:LINER 制造商全称:Linear Technology 功能描述:Monolithic High Voltage Isolated Flyback Converter No External Start-Up Resistor
LT3511EMS#PBF 功能描述:IC REG FLYBACK ISOLATD 16-MSOP 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
LT3511EMS#TRPBF 功能描述:IC REG FLYBK ISO ADJ .24A 16MSOP 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
LT3511HMS#PBF 功能描述:IC REG FLYBK ISO ADJ .24A 16MSOP RoHS:是 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
LT3511HMS#TRPBF 功能描述:IC REG FLYBK ISO ADJ .24A 16MSOP RoHS:是 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