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参数资料
| 型号： | MC34710EWR2 |
| 厂商： | Freescale Semiconductor |
| 文件页数： | 11/18页 |
| 文件大小： | 0K |
| 描述： | IC PWR SUPPLY ADJ DUAL SW 32SOIC |
| 产品变化通告： | AMPD Product Discontinuation 12/Dec/2012 |
| 标准包装： | 1,000 |
| 应用： | 通用，监控器，序列 |
| 电流 - 电源： | 7.5mA |
| 电源电压： | 13 V ~ 32 V |
| 工作温度： | 0°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 32-SSOP（0.295"，7.50mm 宽）裸露焊盘 |
| 供应商设备封装： | 32-SOICW 裸露焊盘 |
| 包装： | 带卷 (TR) |
TYPICAL APPLICATIONS
TYPICAL APPLICATIONS
B+
13- 32V
C1
330 μ F
R1
1K
C1
0.1mF
CP2
B+
VFB
LINB
VCORE
SW1
1
2
3
4
RST
MODE0
MODE1
MODE2
SUPERVISORY
& SHUTDOWN
CHARGE
PUMP
BUCK
REG
LDO
CT 32
31
CP1
30
VB 29
28
27
VSW
26
25
24
23
C5
0.1 μ F
C6
10 μ F
RSERIES
1.8
L1
100 μ H
D1
MBRS130LT3
C8
330 μ F
13
GND
MC34710
1
V I/O
Figure 4. Typical Application Diagram
2
V CORE
The MC34710 provides both a buck converter and an LDO
regulator in one IC. Figure 4 above shows a typical
application schematic for the MC34710. L1 is the buck
converter's inductor. The buck inductor is a key component
and must not only present the required reactance, but do so
at a DC resistance of less than 20 milliohms in order to
preserve the converter's efficiency. Also important to the
converter's efficiency is the utilization of a low V F Schottky
diode for D1.
Note that a 0.1uF capacitor is connected between CT and
the reset pins; this prevents any possibility of oscillations
occurring on the reset line during transitions by allowing the
CT pin to discharge to ground potential via the RST pin, and
then charge when RST returns to a logic high. The capacitor
between the CP1 and CP2 pins is the charge pump's “bucket
capacitor”, and sequentially charges and discharges to pump
up the reservoir capacitor connected to the VB pin. Note that
the reservoir capacitor's cathode is connected to B+ rather
than ground. Also note that the charge pump is intended only
to provide gate-drive potential for the buck regulator's internal
power MOSFET, and therefore connecting external loads to
the VB pin is not recommended.
The IC's internal V CORE LDO regulator can provide up to
500mA of current as long as the operating junction
temperature is maintained below 105 degrees C. The heat-
generating power dissipation of the LDO is primarily a
function of the Volt x Amp product across the LINB+ and
VCORE pins. Therefore, if the LINB+ voltage is >> than the
selected V CORE voltage + 0.8V, it is recommended to use a
power resistor in series with the LINB+ input to drop the
voltage and dissipate the heat externally from the IC. For
example, if the output of the buck regulator (V I/O on the
schematic) is used as the input to LINB+, and the mode
switches are set such that V I/O = 5V and V CORE = 3.3 , then
a series resistance of 1.8 ohms at the LINB+ pin would
provide an external voltage drop at 500mA while still leaving
the minimum required headroom of 0.8V. Conversely, if the
mode switches are set such that V I/O = 3.3V and V CORE =
2.5V, then no series resistance would be required, even at
the maximum output current of 500mA.
Designing a power supply circuit with the MC34710, like all
DC-DC converter ICs, requires special attention not only to
component selection, but also to component placement (i.e.,
printed circuit board layout). The MC34710 has a nominal
switching frequency of 200kHz, and therefore pcb traces
between the buck converter discrete component pins and the
IC should be kept as short and wide as possible to keep the
parasitic inductance low. Likewise, keeping these pcb traces
34710
Analog Integrated Circuit Device Data
Freescale Semiconductor
11
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MC34711 | 制造商:SPC Multicomp 功能描述:HEADER R/ANGLE 14WAY 制造商:SPC Multicomp 功能描述:HEADER, R/ANGLE, 14WAY 制造商:SPC Multicomp 功能描述:WIRE-BOARD CONN, RECEPTACLE, 14POS, 3MM; Series:2261(5561); Pitch Spacing:3mm; Contact Termination:Through Hole Right Angle; No. of Contacts:14; No. of Rows:2; Connector Mounting:PCB; Gender:Receptacle; Contact Material:Copper Alloy ;RoHS Compliant: Yes |
| MC34712EP | 功能描述:开关变换器、稳压器与控制器 SINGLE REGULATOR FOR DDR RoHS:否 制造商:Texas Instruments 输出电压:1.2 V to 10 V 输出电流:300 mA 输出功率: 输入电压:3 V to 17 V 开关频率:1 MHz 工作温度范围: 安装风格:SMD/SMT 封装 / 箱体:WSON-8 封装:Reel |
| MC34712EPR2 | 功能描述:开关变换器、稳压器与控制器 SNGL REGULTR FOR DDR RoHS:否 制造商:Texas Instruments 输出电压:1.2 V to 10 V 输出电流:300 mA 输出功率: 输入电压:3 V to 17 V 开关频率:1 MHz 工作温度范围: 安装风格:SMD/SMT 封装 / 箱体:WSON-8 封装:Reel |
| MC34713 | 制造商:SPC Multicomp 功能描述:HEADER R/ANGLE 20WAY 制造商:SPC Multicomp 功能描述:HEADER, R/ANGLE, 20WAY |
| MC34713EP | 功能描述:开关变换器、稳压器与控制器 SINGLE SWITCH REG RoHS:否 制造商:Texas Instruments 输出电压:1.2 V to 10 V 输出电流:300 mA 输出功率: 输入电压:3 V to 17 V 开关频率:1 MHz 工作温度范围: 安装风格:SMD/SMT 封装 / 箱体:WSON-8 封装:Reel |
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