- 您现在的位置：买卖IC网 > PDF目录17212 > DC1274A (Linear Technology)BOARD DEMO LTM8040 PDF资料下载
参数资料
| 型号： | DC1274A |
| 厂商： | Linear Technology |
| 文件页数： | 12/20页 |
| 文件大小： | 0K |
| 描述： | BOARD DEMO LTM8040 |
| 设计资源： | LTM8040 Spice Model DC1274A Schematic |
| 标准包装： | 1 |
| 系列： | µModule® |
| 电流 - 输出 / 通道： | 1A |
| 输出及类型： | 1，非隔离 |
| 输出电压： | 13V |
| 特点： | PWM 控制 |
| 输入电压： | 4 V ~ 36 V |
| 已供物品： | 板 |
| 已用 IC / 零件： | LTM8040 |
LTM8040
APPLICATION INFORMATION
I RATIO =
= 10:1
PWM RATIO =
= 250:1
= PWM RATIO
PWM dimming control (Figure 5) uses the PWM pin and
an external NFET tied to the cathode of the LED. When the
PWM signal goes low, the NFET turns off, disconnecting
the LED from the internal current source and “freezing”
the state of LTM8040 internal control and drive circuitry,
but leaving the output capacitor of the internal step-down
converter charged. When the PWM pin goes high again,
the LED current returns rapidly to its previous on state.
This fast settling time allows the LTM8040 to maintain
LED current regulation with PWM pulse widths as short
as 40μs. It is also possible to not use an external NFET,
but the output capacitor of the internal regulator will be
discharged by the LED(s) and have to be charged up again
when the current source turns back on. This will lengthen
the minimum dimming pulse width.
The maximum PWM dimming ratio (PWM RATIO ) can
be calculated from the maximum PWM period (t MAX )
and minimum PWM pulse width (t MIN ) as follows:
t MAX
t MIN
Totaldimmingratio(DIM RATIO )istheproductofthePWM
dimming ratio and the current dimming ratio.
PWM
60Hz TO
10kHz
Example: I MAX = 1A, I MIN = 0.1A, t MAX = 10ms,
t MIN = 40μs
1A
0.1A
10ms
40μs
DIM RATIO = 10 ? 250 = 2500:1
Minimum Input Voltage
The LTM8040 is a step-down converter, so a minimum
amount of headroom is required to keep the output in
regulation. For most applications at full load, the input
needs to be at least 1.5V above the desired output. In
addition, it takes more input voltage to initially start than
is required for continuous operation. This start voltage is
also dependent on whether turn-on is controlled by the
LTM8040’s SHDN pin or UVLO (that is, the SHDN pin is
tied to V IN ). See Typical Performance Characteristics for
details.
PWM
LTM8040
LEDA
GND
8040 F05
Figure 5. Dimming Using PWM Signal
8040fa
12
相关PDF资料 |
PDF描述 |
|---|---|
| RB-243.3S/HP | CONV DC/DC 1W 24VIN 3.3VOUT |
| EEM15DRYH-S13 | CONN EDGECARD 30POS .156 EXTEND |
| T95S155K020CZSL | CAP TANT 1.5UF 20V 10% 1507 |
| T95S154M035CZSL | CAP TANT 0.15UF 35V 20% 1507 |
| 050R15-76B | CABLE FLAT FLEX 15POS 0.5MM 3" |
相关代理商/技术参数 |
参数描述 |
|---|---|
| DC1278A | 功能描述:BOARD SAR ADC LTC2351-14 RoHS:是 类别:编程器，开发系统 >> 评估板 - 模数转换器 (ADC) 系列:QuikEval-II™ 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:- ADC 的数量:1 位数:12 采样率（每秒）:94.4k 数据接口:USB 输入范围:±VREF/2 在以下条件下的电源（标准）:- 工作温度:-40°C ~ 85°C 已用 IC / 零件:MAX11645 已供物品:板，软件 |
| DC1280A | 制造商:Linear Technology 功能描述:EVAL BOARD, LT3471 BOOST / INVERTING REG 制造商:Linear Technology 功能描述:EVAL BOARD, LT3471 BOOST / INVERTING REG; Silicon Manufacturer:Linear Technology; Silicon Core Number:LT3471; Kit Application Type:Power Management; Kit Contents:Evaluation Board for LT3471; Length:40mm |
| DC1281A-A | 制造商:Linear Technology 功能描述:BOARD DEMO 16BIT 160MSPS LTC2209 制造商:Linear Technology 功能描述:16BIT ADC Eval Brd, Rq. DC1371 制造商:Linear Technology 功能描述:16BIT ADC Eval Brd, Rq. DC1371, Silicon Manufacturer:Linear Technology, Silicon Core Number:LTC2209UP, Kit Application Type:Data Converter, Application Sub Type:ADC, Kit Contents:Board, Guide, Features:Also works with requred DC1371 |
| DC1281A-B | 制造商:Linear Technology 功能描述:BOARD DEMO 16BIT 160MSPS LTC2209 制造商:Linear Technology 功能描述:16BIT ADC Eval Brd, Rq. DC1371 制造商:Linear Technology 功能描述:16BIT ADC Eval Brd, Rq. DC1371; Silicon Manufacturer:Linear Technology; Silicon Core Number:LTC2209UP; Kit Application Type:Data Converter; Application Sub Type:ADC; Kit Contents:Board, Guide; Features:Also works with requred DC1371 |
| DC1281A-E | 制造商:Linear Technology 功能描述:16BIT ADC Eval Brd, Rq. DC1371, Silicon Manufacturer:Linear Technology, Silicon |
发布紧急采购，3分钟左右您将得到回复。