参数资料
型号: LTC3812EFE-5#PBF
厂商: Linear Technology
文件页数: 12/34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:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
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)
LTC3812-5
OPERATION
level to initiate another cycle. In this mode, frequency is
proportional to load current at light loads.
Pulse-skipping mode operation is disabled by comparator F
when the FCB pin is brought below 0.8V, forcing continuous
synchronous operation. Forced continuous mode is less
ef?cient due to resistive losses, but has the advantage of
better transient response at low currents, approximately
constant frequency operation, and the ability to maintain
regulation when sinking current.
Fault Monitoring/Protection
Constant on-time current mode architecture provides ac-
curate cycle-by-cycle current limit protection—a feature
that is very important for protecting the high voltage power
gates quickly. This minimizes transition losses and allows
paralleling MOSFETs for higher current applications. A
60V ?oating high side driver drives the topside MOSFET
and a low side driver drives the bottom side MOSFET
(see Figure 3). The bottom side driver is supplied directly
from the INTV CC pin. The top MOSFET drivers are biased
from ?oating bootstrap capacitor C B , which normally is
recharged during each off cycle through an external diode
from INTV CC when the top MOSFET turns off. In pulse-
skipping mode operation, where it is possible that the
bottom MOSFET will be off for an extended period of time,
an internal timeout guarantees that the bottom MOSFET is
turned on at least once every 25μs for one on-time period
to refresh the bootstrap capacitor.
supply from output short-circuits. The cycle-by-cycle cur-
INTV CC
V IN
rent monitor guarantees that the inductor current will never
exceed the value programmed on the V RNG pin.
LTC3812-5
INTV CC
BOOST
D B
+
C IN
Foldback current limiting provides further protection if the
output is shorted to ground. As V FB drops, the buffered
current threshold voltage I THB is pulled down and clamped
to 1V. This reduces the inductor valley current level to
one-sixth of its maximum value as V FB approaches 0V.
TG
SW
BG
C B
M1
M2
L
+
V OUT
C OUT
Foldback current limiting is disabled at start-up.
PGND
38125 F03
Overvoltage and undervoltage comparators OV and UV
pull the PGOOD output low if the output feedback voltage
exits a ±10% window around the regulation point after the
internal 120μs power bad mask timer expires. Furthermore,
in an overvoltage condition, M1 is turned off and M2 is
turned on immediately and held on until the overvoltage
condition clears.
The LTC3812-5 provides an undervoltage lockout com-
parator for the INTV CC supply. The INTV CC UV threshold
is 4.2V to guarantee that the MOSFETs have suf?cient
gate drive voltage before turning on. If INTV CC is under
the UV threshold, the LTC3812-5 is shut down and the
drivers are turned off.
Strong Gate Drivers
The LTC3812-5 contains very low impedance drivers
capable of supplying amps of current to slew large MOSFET
Figure 3. Floating TG Driver Supply and Negative BG Return
IC/Driver Supply Power
The LTC3812-5’s internal control circuitry and top and
bottom MOSFET drivers operate from a supply voltage
(INTV CC pin) in the range of 4.2V to 14V. The LTC3812-5
has two integrated linear regulator controllers to easily
generate this IC/driver supply from either the high voltage
input or from the output voltage. For best ef?ciency the
supply is derived from the input voltage during start-up
and then derived from the lower voltage output as soon
as the output is higher than 4.7V. Alternatively, the supply
can be derived from the input continuously if the output is
< 4.7V or an external supply in the appropriate range can
be used. The LTC3812-5 will automatically detect which
mode is being used and operate properly.
38125fc
12
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