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参数资料
| 型号： | LTC1142CG |
| 厂商： | Linear Technology |
| 文件页数： | 8/20页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 28-SSOP |
| 标准包装： | 47 |
| PWM 型： | 电流模式 |
| 输出数： | 2 |
| 频率 - 最大： | 250kHz |
| 占空比： | 100% |
| 电源电压： | 3.5 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： | -40°C ~ 85°C |
| 封装/外壳： | 28-SSOP（0.209"，5.30mm 宽） |
| 包装： | 管件 |
| 产品目录页面： | 1332 (CN2011-ZH PDF) |
LTC1142/LTC1142L/LTC1142HV
FU CTIO AL DIAGRA
Only one regulator block shown. Pin numbers are for 3.3V (5V) sections for LTC1142/LTC1142HV,
and V OUT1 (V OUT2 ) for LTC1142L-ADJ/LTC1142HV-ADJ.
2(16)
PIN NUMBERS FOR
LTC1142, LTC1142HV
SGND
LTC1142L-ADJ
LTC1142-ADJ
3(17)
PIN NUMBERS
FOR LTC1142L-ADJ
24(10) V IN
3(17)
LTC1142HV-ADJ
4(18)
LTC1142HV-ADJ
23(9)
PDRIVE
SENSE +
SENSE –
1(15)
28(14)
LTC1142L-ADJ
LTC1142HV-ADJ
6(20)
NDRIVE
2(16)
4(18) PGND
LTC1142L-ADJ, LTC1142HV-ADJ: 5(19)
–
NC/ADJ
SLEEP
V
+
I TH
S
+
–
V TH2
V TH1
Q
–
R
S
C
–
+
25mV TO 150mV
– +
13k
–
V OS
5pF
+
T
27(13)
G
+
1.25V
100k
25(11)
C T
OFF-TIME
CONTROL
V IN
SENSE –
SHDN
2(16)
LTC1142L-ADJ
REFERENCE
INTV CC
26(12)
LTC1142HV-ADJ
3(17)
1142 BD
OPERATIO
Refer to Functional Diagram
The LTC1142 series consists of two individual regulator
blocks, each using current mode, constant off-time archi-
tectures to synchronously switch an external pair of
complementary power MOSFETs. The two regulators are
internally set to provide output voltages of 3.3V and 5V for
the LTC1142. The LTC1142HV-ADJ/LTC1142L-ADJ are
configured to provide two user selectable output voltages,
each set by external resistor dividers. Operating fre-
quency is individually set on each section by the external
capacitors at C T , Pins 11 and 25.
The output voltage is sensed by an internal voltage divider
connected to Sense – , Pin 28 (14) (LTC1142) or external
divider returned to V FB , Pin 2 (16) (LTC1142-ADJ). A
voltage comparator V and a gain block G compare the
divided output voltage with a reference voltage of 1.25V.
To optimize efficiency, the LTC1142 series automatically
switches between two modes of operation, Burst Mode
and continuous mode. The voltage comparator is the
primary control element when the device is in Burst Mode
operation, while the gain block controls the output voltage
in continuous mode.
8
During the switch “ON” cycle in continuous mode, current
comparator C monitors the voltage between Pins 1 (15)
and 28 (14) connected across an external shunt in series
with the inductor. When the voltage across the shunt
reaches its threshold value, the PDrive output is switched
to V IN , turning off the P-channel MOSFET. The timing
capacitor connected to Pin 25 (11) is now allowed to
discharge at a rate determined by the off-time controller.
The discharge current is made proportional to the output
voltage [measured by Pin 28 (14)] to model the inductor
current, which decays at a rate that is also proportional to
the output voltage. While the timing capacitor is discharg-
ing, the NDrive output goes to V IN , turning on the N-channel
MOSFET.
When the voltage on the timing capacitor has discharged
past V TH1 , comparator T trips, setting the flip-flop. This
causes the NDrive output to go low (turning off the
N-channel MOSFET) and the PDrive output to also go low
(turning the P-channel MOSFET back on). The cycle then
repeats.
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相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC1142CG#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:- 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) |
| LTC1142CG#TR | 功能描述:IC REG CTRLR BUCK PWM CM 28-SSOP 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: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 |
| LTC1142CG#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:- 标准包装:4,000 系列:- PWM 型:电压模式 输出数:1 频率 - 最大:1.5MHz 占空比:66.7% 电源电压:4.75 V ~ 5.25 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 ~ 85°C 封装/外壳:40-VFQFN 裸露焊盘 包装:带卷 (TR) |
| LTC1142HV | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual High Efficiency Synchronous Step-Down Switching Regulators |
| LTC1142HV-ADJ | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual High Efficiency Synchronous Step-Down Switching Regulators |
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