- 您现在的位置：买卖IC网 > PDF目录15292 > LTC1143CS (Linear Technology)IC REG CTRLR BUCK PWM CM 16-SOIC PDF资料下载
参数资料
| 型号： | LTC1143CS |
| 厂商： | Linear Technology |
| 文件页数： | 15/20页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 16-SOIC |
| 标准包装： | 50 |
| PWM 型： | 电流模式 |
| 输出数： | 2 |
| 频率 - 最大： | 400kHz |
| 占空比： | 100% |
| 电源电压： | 3.5 V ~ 16 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： | 16-SOIC（0.154"，3.90mm 宽） |
| 包装： | 管件 |
| 其它名称： | LTC1143CSW LTC1143CSW-ND |
LTC1143/LTC1143L
LTC1143L-ADJ
APPLICATIO N S I N FOR M ATIO N
3.3V
With the addition of R3 a current is generated though R1,
causing an offset of:
0V
V OFFSET OUT ?
?
(a) CONTINUOUS MODE OPERATION
(b) Burst Mode OPERATION
Figure 7. C T Waveforms
Auxiliary Windings ––Suppressing Burst Mode
3.3V
0V
LTC1143 ? F07
? R 1 ?
= V
? R 1 + R 3 ?
If V OFFSET > 25mV, the built-in offset will be cancelled and
Burst Mode operation is prevented from occurring. Since
V OFFSET is constant, the maximum load current is also
decreased by the same offset. Thus, to get back to the
same I MAX , the value of the sense resistor must be lower:
Operation
The LTC1143 series operates nonsynchronously with the
normal limitation that the power drawn from the inductor
R SENSE ≈
75mV
I MAX
primary winding must not be less than twice the power
drawn from the auxiliary windings. (With synchronous
switching, using the LTC1142 series, auxiliary outputs
may be loaded without regard to the primary output load,
providing that the loop remains in continuous mode
operation.)
Burst Mode operation can be suppressed at low output
currents with a simple external network that cancels the
25mV minimum current comparator threshold. This tech-
nique is also useful for eliminating audible noise from
certain types of inductors in high current (I OUT > 5A)
applications when they are lightly loaded.
An external offset is put in series with the Sense – pin to
subtract from the built-in 25mV offset. An example of this
technique is shown in Figure 8. Two 100 ? resistors are
inserted in series with the sense leads from the sense
resistor.
To prevent noise spikes from erroneously tripping the
current comparator, a 1000pF capacitor is needed across
Pins 1 (16) and 9 (8).
Board Layout Checklist
When laying out the printed circuit board, the following
checklist should be used to ensure proper operation of the
LTC1143 series. These items are also illustrated graphi-
cally in the layout diagram of Figure 9. In general, each
block should be self-contained with little cross coupling
for best performance. Check the following in your layout:
1) Are the signal and power grounds segregated? The
LTC1143 series GND Pin 3 (11) must return separately
to: a) the power and b) the signal grounds. The
power ground returns to the anode of the Schottky
diode and (–) plate of C IN , which should have as short
lead lengths as possible.The signal ground (b) con-
nects to the (–) plate of C OUT .
SENSE +
R2
100 ?
2) Does the LTC1143 series SENSE – Pin 16 (8) connect
to a point close to R SENSE and the (+) plate of C OUT ?
[PIN 16 (8)]
SENSE –
[PIN 1(9)]
1000pF
R1
100 ?
+
R SENSE
V OUT
3) Are the SENSE – and SENSE + leads routed together
with minimum PC trace spacing? The 1000pF
capacitor between Pins 1 (9) and 16 (8) should be as
R3
C OUT
1143 F08
close as possible to the LTC1143 series.
4) Does the (+) plate of C IN connect to the source of the
P-channel MOSFET as closely as possible? This
Figure 8. Suppression of Burst Mode Operation
capacitor provides the AC current to the P-channel
MOSFET.
15
相关PDF资料 |
PDF描述 |
|---|---|
| VI-220-EY-F1 | CONVERTER MOD DC/DC 5V 50W |
| VE-JWK-EY-F4 | CONVERTER MOD DC/DC 40V 50W |
| LTC3716EG | IC REG CTRLR BUCK PWM CM 36-SSOP |
| RYM24DRMN-S288 | CONN EDGECARD 48POS .156 EXTEND |
| LTC1266IS#PBF | IC REG CTRLR BST PWM CM 16-SOIC |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC1143CS#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 16-SOIC 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) |
| LTC1143CS#TR | 功能描述:IC REG CTRLR BUCK PWM CM 16-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) |
| LTC1143CS#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 16-SOIC 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) |
| LTC1143L | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual High Efficiency SO-16 Step-Down Switching Regulator Controllers |
| LTC1143L-ADJ | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual High Efficiency SO-16 Step-Down Switching Regulator Controllers |
发布紧急采购，3分钟左右您将得到回复。