- 您现在的位置：买卖IC网 > PDF目录1832 > LTC3812EFE-5#PBF (Linear Technology)IC REG CTRLR BUCK PWM CM 16TSSOP PDF资料下载
参数资料
| 型号： | LTC3812EFE-5#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 16/34页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 16TSSOP |
| 标准包装： | 95 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 1MHz |
| 占空比： | 93% |
| 电源电压： | 6.2 V ~ 60 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： | 16-TSSOP（0.173"，4.40mm）裸露焊盘 |
| 包装： | 管件 |
| 产品目录页面： | 1336 (CN2011-ZH PDF) |
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页第15页当前第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页第29页第30页第31页第32页第33页第34页
LTC3812-5
APPLICATIONS INFORMATION
drain current. C MILLER is the calculated capacitance using
the gate charge curve from the MOSFET data sheet and
the technique described above.
Both MOSFETs have I 2 R losses while the topside N-chan-
nel equation incudes an additional term for transition
losses, which peak at the highest input voltage. For high
input voltage low duty cycle applications that are typical
for the LTC3812-5, transition losses are the dominate
loss term and therefore using higher R DS(ON) device with
lower C MILLER usually provides the highest ef?ciency. The
synchronous MOSFET losses are greatest at high input
voltage when the top switch duty factor is low or during a
OPERATING FREQUENCY
The choice of operating frequency is a tradeoff between
ef?ciency and component size. Low frequency operation
improves ef?ciency by reducing MOSFET switching losses
but requires larger inductance and/or capacitance in order
to maintain low output ripple voltage.
The operating frequency of LTC3812-5 applications is
determined implicitly by the one-shot timer that controls
the on-time t ON of the top MOSFET switch. The on-time
is set by the current out of the I ON pin and the voltage at
the V ON pin according to:
short-circuit when the synchronous switch is on close to
100% of the period. Since there is no transition loss term
in the synchronous MOSFET, optimal ef?ciency is obtained
t ON =
2.4V
I ION
(76pF)
by minimizing R DS(ON) —by using larger MOSFETs or
paralleling multiple MOSFETS.
Multiple MOSFETs can be used in parallel to lower
R DS(ON) and meet the current and thermal requirements
if desired. The LTC3812-5 contains large low impedance
Tying a resistor R ON from V IN to the I ON pin yields an
on-time inversely proportional to V IN . For a step-down
converter, this results in approximately constant frequency
operation as the input supply varies:
drivers capable of driving large gate capacitances without
signi?cantly slowing transition times. In fact, when driv-
ing MOSFETs with very low gate charge, it is sometimes
f =
V OUT
2.4V ? R ON (76pF)
[ Hz]
helpful to slow down the drivers by adding small gate
resistors (10Ω or less) to reduce noise and EMI caused
by the fast transitions.
Figure 7 shows how R ON relates to switching frequency
for several common output voltages.
1000
V OUT = 12V
100
V OUT = 3.3V
V OUT = 5V
10
100
R ON (kΩ)
1000
38112 F07
Figure 7. Switching Frequency vs R ON
38125fc
16
相关PDF资料 |
PDF描述 |
|---|---|
| LTC3813EG#PBF | IC REG CTRLR BST PWM CM 28-SSOP |
| LTC3814EFE-5#PBF | IC REG CTRLR BST PWM CM 16-TSSOP |
| LTC3816IFE#TRPBF | IC CONTROLLER S-PHASE 38TSSOP |
| LTC3819EG#TRPBF | IC CNTRLR STEP DOWN 36-SSOP |
| LTC3822EGN-1#PBF | IC REG CTRLR BUCK PWM CM 16-SSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3812IFE-5#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 16TSSOP 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:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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:24-WQFN 裸露焊盘 包装:带卷 (TR) |
| LTC3812IFE-5#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 16TSSOP 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:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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:24-WQFN 裸露焊盘 包装:带卷 (TR) |
| LTC3813EG#PBF | 功能描述:IC REG CTRLR BST 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:- 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 |
| LTC3813EG#TRPBF | 功能描述:IC REG CTRLR BST 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:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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:24-WQFN 裸露焊盘 包装:带卷 (TR) |
| LTC3813IG#PBF | 功能描述:IC REG CTRLR BST 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 |
发布紧急采购，3分钟左右您将得到回复。