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參數(shù)資料
| 型號： | DS1244Y |
| 廠商： | MAXIM INTEGRATED PRODUCTS INC |
| 元件分類： | Timer or RTC |
| 英文描述： | 0 TIMER(S), REAL TIME CLOCK, PDIP28 |
| 封裝： | 0.740 INCH, PLASTIC, DIP-28 |
| 文件頁數(shù)： | 6/21頁 |
| 文件大?。?/td> | 1965K |
| 代理商： | DS1244Y |
MAX17129/MAX17149
Low-Cost, 6-String WLED Drivers with
Quick-PWM Step-Up Converter
14
The actual switching frequency can be approximated by:
IN
DSON
s
OFF
OVP
D
IN
DSON
V
I
R
1
f
T
V
I
R
×
=
×
+
×
where:
VD is the forward voltage of the output diode.
RDSON is the on-resistance of the internal MOSFET.
The switching frequency is adjustable by changing the
off-time at each supply turn-on cycle. As mentioned
above, it is implemented by changing the voltage level
of the FSEL pin.
High-frequency operation optimizes the regulator for the
smallest component size at the expense of efficiency
due to increased switching losses. Low-frequency oper-
ation offers the best overall efficiency but requires larger
components and PCB area.
Input Supply Voltage Configuration and
UVLO
The devices include an internal low-dropout linear
regulator (VCC) and are disabled until VCC exceeds the
UVLO threshold. The hysteresis on UVLO is approxi-
mately 100mV. When VIN is higher than 6V with EN high,
this linear regulator generates a 3.8V supply to power
the internal PWM controller, control logic, and MOSFET
driver. The VCC voltage drops to 0V with EN low. When
the VCC and IN pins are connected together, the devices
can operate in a low input-voltage range from 3V to 5.5V.
Figure 4. MAX17129/MAX17149 Quick-PWM Control Functional Diagram
LX
OVP
VIN
IN
EN
OVP
FB
FSEL
MAX17129
MAX17149
ON- /OFF-TIME
CALCULATION
ONE-SHOT
CURRENT
SENSE
REF
INT
ERROR
COMPARATOR
SS
SOFT-START
INTEGRATOR
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| DS1245AB-100 | 128K X 8 NON-VOLATILE SRAM MODULE, 100 ns, DMA32 |
| DS1245Y-120 | 128K X 8 NON-VOLATILE SRAM MODULE, 120 ns, DMA32 |
| DS1245AB-85 | 128K X 8 NON-VOLATILE SRAM MODULE, 85 ns, DMA32 |
| DS1245Y-85 | 128K X 8 NON-VOLATILE SRAM MODULE, 85 ns, DMA32 |
| DS1245Y-70 | 128K X 8 NON-VOLATILE SRAM MODULE, 70 ns, DMA32 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DS1244Y120 | 制造商:Maxim Integrated Products 功能描述: |
| DS1244Y-120 | 制造商:Maxim Integrated Products 功能描述: |
| DS1244Y-150 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| DS1244Y-200 | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:256K NV SRAM with Phantom Clock |
| DS1244Y-70 | 功能描述:實時時鐘 RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 總線接口:I2C 日期格式:DW:DM:M:Y 時間格式:HH:MM:SS RTC 存儲容量:64 B 電源電壓-最大:5.5 V 電源電壓-最小:1.8 V 最大工作溫度:+ 85 C 最小工作溫度: 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube |
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