- 您现在的位置：买卖IC网 > PDF目录15310 > LTC1622CMS8 (Linear Technology)IC REG CTRLR BUCK PWM CM 8-MSOP PDF资料下载
参数资料
| 型号： | LTC1622CMS8 |
| 厂商： | Linear Technology |
| 文件页数： | 6/16页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 8-MSOP |
| 标准包装： | 50 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 625kHz |
| 占空比： | 100% |
| 电源电压： | 2 V ~ 10 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： | 0°C ~ 70°C |
| 封装/外壳： | 8-TSSOP，8-MSOP（0.118"，3.00mm 宽） |
| 包装： | 管件 |
| 产品目录页面： | 1333 (CN2011-ZH PDF) |
LTC1622
OPERATIO
(Refer to Functional Diagram)
the I TH pin will drop. When the I TH voltage goes below
0.12V, the sleep signal goes high, turning off the external
MOSFET. The sleep signal goes low when the I TH voltage
rises above 0.22V and the LTC1622 resumes normal
operation. The next oscillator cycle will turn the external
MOSFET on and the switching cycle repeats.
Frequency Synchronization
The LTC1622 can be externally driven by a TTL/CMOS
compatible clock signal up to 750kHz. Do not synchronize
the LTC1622 below its maximum default operating fre-
quency of 625kHz as this may cause abnormal operation
and an undesired frequency spectrum. The LTC1622 is
synchronized to the rising edge of the clock. The external
clock pulse width must be at least 100ns and not more
than the period minus 200ns.
Synchronization is inhibited when the feedback voltage is
below 0.3V. This is to prevent inductor current buildup
under short-circuit conditions. Burst Mode operation is
deactivated when the LTC1622 is externally driven by a
Short-Circuit Protection
When the output is shorted to ground, the frequency of the
oscillator will be reduced to about 110kHz. This lower
frequency allows the inductor current to safely discharge,
thereby preventing current runaway. The oscillator’s fre-
quency will gradually increase to its nominal value when
the feedback voltage increases above 0.65V. Note that
synchronization is inhibited until the feedback voltage
goes above 0.3V.
Overvoltage Protection
As a further protection, the overvoltage comparator in the
LTC1622 will turn the external MOSFET off when the
feedback voltage has risen 16% above the reference
voltage of 0.8V. This comparator has a typical hysteresis
of 35mV.
Slope Compensation and Peak Inductor Current
The inductor’s peak current is determined by:
(
clock.
Dropout Operation
I PK =
V ITH
10 R SENSE
)
When the input supply voltage decreases towards the
output voltage, the rate of change of inductor current
during the ON cycle decreases. This reduction means that
the P-channel MOSFET will remain on for more than one
oscillator cycle since the inductor current has not ramped
up to the threshold set by EA. Further reduction in input
supply voltage will eventually cause the P-channel MOSFET
to be turned on 100%, i.e., DC. The output voltage will then
be determined by the input voltage minus the voltage drop
across the MOSFET, the sense resistor and the inductor.
Undervoltage Lockout
when the LTC1622 is operating below 40% duty cycle.
However, once the duty cycle exceeds 40%, slope com-
pensation begins and effectively reduces the peak induc-
tor current. The amount of reduction is given by the curves
in Figure 2.
110
100
90
80
70
60
To prevent operation of the P-channel MOSFET below safe
input voltage levels, an undervoltage lockout is incorpo-
rated into the LTC1622. When the input supply voltage
drops below 2V, the P-channel MOSFET and all circuitry is
turned off except the undervoltage block, which draws
only several microamperes.
50
40
30
20
10
0
I RIPPLE = 0.4I PK
AT 5% DUTY CYCLE
I RIPPLE = 0.2I PK
AT 5% DUTY CYCLE
V IN = 4.2V
UNSYNC
10 20 30 40 50 60 70 80 90 100
DUTY CYCLE (%)
1622 F02
Figure 2. Maximum Output Current vs Duty Cycle
6
相关PDF资料 |
PDF描述 |
|---|---|
| VI-2WD-EW-F3 | CONVERTER MOD DC/DC 85V 100W |
| LT1725IS#TRPBF | IC REG CTRLR FLYBK ISO CM 16SOIC |
| SRP1235-R47M | INDUCTOR 470NH 32A SMD |
| EEC49DREH-S93 | CONN EDGECARD 98POS .100 EYELET |
| ADM1060ARU-REEL | IC SUPERVISOR/SEQUENCER 28TSSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC1622CMS8#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 8-MSOP 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 |
| LTC1622CMS8#TR | 功能描述:IC REG CTRLR BUCK PWM CM 8-MSOP RoHS:否 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) |
| LTC1622CMS8#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 8-MSOP 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) |
| LTC1622CS8 | 功能描述:IC REG CTRLR BUCK PWM CM 8-SOIC RoHS:否 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) |
| LTC1622CS8#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 8-SOIC 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 |
发布紧急采购，3分钟左右您将得到回复。