参数资料
型号: LTC3827IUH
厂商: LINEAR TECHNOLOGY CORP
元件分类: 稳压器
英文描述: 3 A DUAL SWITCHING CONTROLLER, 580 kHz SWITCHING FREQ-MAX, PQCC32
封装: 5 X 5 MM, PLASTIC, MO-220WHHD, QFN-32
文件页数: 13/36页
文件大小: 451K
代理商: LTC3827IUH
LTC3827
20
3827ff
APPLICATIONS INFORMATION
providing a linear ramping voltage at the TRACK/SS pin.
The LTC3827 will regulate the VFB pin (and hence VOUT)
according to the voltage on the TRACK/SS pin, allowing
VOUT to rise smoothly from 0V to its nal regulated value.
The total soft-start time will be approximately:
tSS = CSS
0.8V
1μA
Alternatively, the TRACK/SS pin can be used to track two
(or more) supplies during start-up, as shown qualitatively
in Figures 6a and 6b. To do this, a resistor divider should
be connected from the master supply (VX) to the TRACK/
SS pin of the slave supply (VOUT), as shown in Figure 7.
During start-up VOUT will track VX according to the ratio
set by the resistor divider:
VX
VOUT
=
RA
RTRACKA
RTRACKA +RTRACKB
RA +RB
For coincident tracking (VOUT = VX during start-up),
RA = RTRACKA
RB = RTRACKB
INTVCC Regulators
The LTC3827 features two separate internal P-channel low
dropout linear regulators (LDO) that supply power at the
INTVCC pin from either the VIN supply pin or the EXTVCC
pin, respectively, depending on the connection of the
EXTVCC pin. INTVCC powers the gate drivers and much of
the LTC3827’s internal circuitry. The VIN LDO regulates
the voltage at the INTVCC pin to 5.25V and the EXTVCC
LDO regulates it to 7.5V. Each of these can supply a peak
current of 50mA and must be bypassed to ground with
a minimum of 4.7μF tantalum, 10μF special polymer, or
low ESR electrolytic capacitor. A ceramic capacitor with a
minimum value of 4.7μF can also be used if a 1Ω resistor
is added in series with the capacitor. No matter what type of
bulk capacitor is used, an additional 1μF ceramic capacitor
placed directly adjacent to the INTVCC and PGND IC pins is
highly recommended. Good bypassing is needed to supply
the high transient currents required by the MOSFET gate
drivers and to prevent interaction between the channels.
High input voltage applications in which large MOSFETs
are being driven at high frequencies may cause the maxi-
mum junction temperature rating for the LTC3827 to be
exceeded. The INTVCC current, which is dominated by the
Figure 7. Using the TRACK/SS Pin for Tracking
Figure 6. Two Different Modes of Output
Voltage Tracking
TIME
(6a) Coincident Tracking
VX(MASTER)
VOUT(SLAVE)
OUTPUT
VOL
TAGE
3827 F06a
VX(MASTER)
VOUT(SLAVE)
TIME
3827 F06b
(6b) Ratiometric Tracking
OUTPUT
VOL
TAGE
1/2 LTC3827
VOUT
Vx
VFB
TRACK/SS
3827 F07
RB
RA
RTRACKA
RTRACKB
相关PDF资料
PDF描述
LTC3827IUH#TR 3 A DUAL SWITCHING CONTROLLER, 580 kHz SWITCHING FREQ-MAX, PQCC32
LTC4010EFE 0.2 A BATTERY CHARGE CONTROLLER, 640 kHz SWITCHING FREQ-MAX, PDSO16
LTC4065LXEDC#PBF 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO6
LTC4065LXEDC#TRM 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO6
LTC4065LEDC#PBF 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO6
相关代理商/技术参数
参数描述
LTC3827IUH#PBF 功能描述:IC REG CTRLR BUCK PWM CM 32-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:PolyPhase® 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
LTC3827IUH#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 32-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:PolyPhase® 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
LTC3828EG#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:PolyPhase® 标准包装:2,000 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:1MHz 占空比:50% 电源电压:9 V ~ 10 V 降压:无 升压:是 回扫:是 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 85°C 封装/外壳:8-TSSOP(0.173",4.40mm 宽) 包装:带卷 (TR)
LTC3828EG#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:PolyPhase® 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
LTC3828EUH 制造商:Linear Technology 功能描述:DC DC Cntrlr Dual-OUT Sync Step Down 4.5V to 28V Input 32-Pin QFN EP