参数资料
| 型号： | NCP5332ADW |
| 厂商： | ON Semiconductor |
| 文件页数： | 27/30页 |
| 文件大小： | 0K |
| 描述： | IC CTLR BUCK 2PH DRVR/DAC 28SOIC |
| 产品变化通告： | Product Obsolescence 30/Sept/2009 |
| 标准包装： | 26 |
| 应用： | 控制器，高性能处理器 |
| 输入电压： | 4.5 V ~ 14 V |
| 输出数： | 2 |
| 输出电压： | 可调 |
| 工作温度： | 0°C ~ 70°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-SOIC（0.295"，7.50mm 宽） |
| 供应商设备封装： | 28-SOIC |
| 包装： | 管件 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页当前第27页第28页第29页第30页
NCP5332A
PD,SYNCH + (IRMS,SYNCH2 @ RDS(on))
5. MOSFET & Heatsink Selection
The NTB85N03T1 from ON Semiconductor is chosen for
both the control and synchronous MOSFET due to its low
R DS(on) and low gate?charge requirements. The following
parameters are derived from the NTB85N03T1 data sheet:
Rds ON = 3.9 m ? @ 10 V
Q SWITCH = 25 nC
Q RR = 45 nC
Q OSS = 35 nC
Vf diode = 0.86 V @ 25 A
θ JC = 1.0 ° C/W
NCP5332A Parameters:
i G = 1.5 A
V G = 10 V
t_nonoverlap = 65 ns
The RMS value of the current in the control MOSFET is
calculated from Equation 20 and the previously derived
values for D, I LMAX , and I LMIN at the converter’s maximum
output current:
(26)
) (Vfdiode @ IO,MAX 2 @ t_nonoverlap @ fSW)
+ (21.12 ARMS @ 3.9 m W )
) (0.86 V @ 45 A 2 @ 65 ns @ 220 kHz)
+ 1.74 W ) 0.28 W + 2.02 W
Equation 28 is used to calculate the heat sink thermal
impedances necessary to maintain less than the specified
maximum junction temperatures at 60 ° C ambient:
q CNTL t (125 * 60 ° C) 1.6 W * 1.0 ° C W + 40 ° C W
q SYNCH t (125 * 60 ° C) 2.02 W * 1.0 ° C W + 31 ° C W
If board area permits, a cost effective heatsink could be
formed by using a TO?263 mounting pad of at least 1.5 in 2
for the upper MOSFET and 2.5 in 2 for the lower MOSFET
on a single?sided, 1 oz. copper PCB. The total required pad
area would be slightly less if the area were divided evenly
between top and bottom layers with multiple thermal vias
IRMS,CNTL + [D(ILo,MAX2 ) ILo,MAX @ ILo,MIN
(20)
joining the two areas. To conserve board space, AAVID
PD,CONTROL + (IRMS,CNTL2 @ RDS(on))
) ILo,MIN2) 3]1 2
+ 0.36 @ [(26.52 ) 26.5 @ 18.5 ) 18.52) 3]1 2
+ 8.15 ARMS
Equation 19 is used to calculate the power dissipation of
the control MOSFET:
(19)
) (ILo,MAX @ Qswitch Ig @ VIN @ fSW)
) (Qoss 2 @ VIN @ fSW) ) (VIN @ QRR @ fSW)
+ (8.152 ARMS @ 3.9 m W )
) (26.5 A @ 25 nC 1.5 A @ 12 V @ 220 kHz)
offers clip?on heatsinks for TO?220 thru?hole packages.
Examples of these heatsinks include #577002 (1 ″ × 0.75 ″ ×
0.25 ″ , 33 ° C/W at 2 W) and #591302 (0.75 ″ × 0.5 ″ × 0.5 ″ ,
29 ° C/W at 2 W).
6. Adaptive Voltage Positioning
First, to achieve the 220 kHz switching frequency, use
Figure 4 to determine that a 65 k ? resistor is needed for
R OSC . Then, use Figure 5 to find the V FB bias current at the
corresponding value of R OSC . In this example, the 65 k ?
R OSC resistor results in a V FB bias current of approximately
15 μ A. Knowing the V FB bias current, one can calculate the
required values for R FBK1 and R DRP using Equations 29
through 31.
The no?load position is easily set using Equation 29:
) (35 nC 2 @ 12 V @ 220 kHz)
) (12 V @ 45 nC @ 220 kHz)
+ 0.26 W ) 1.17 W ) 0.05 W ) 0.12 W
+ 1.60 W
RVFBK + D VNO?LOAD IBIASVFB
+ +30 mV 15 m A
+ 2.0 k W
(29)
For inductive current sensing, the designer must calculate
IRMS,SYNCH + [(1 * D) @
D VDRP + IO,MAX @ (RL ) RPCB) @ GVDRP
The RMS value of the current in the synchronous
MOSFET is calculated from Equation 27 and the previously
derived values for D, I Lo,MAX , and I Lo,MIN at the converter’s
maximum output current:
(27)
(ILo,MAX2 ) ILo,MAX @ ILo,MIN ) ILo,MIN2) 3]1 2
+ [(1 * 0.13) @ (26.52 ) 26.5 @ 18.5 ) 18.52) 3]1 2
+ 21.1 ARMS
Equation 26 is used to calculate the power dissipation of
the synchronous MOSFET:
the inductor ’s resistance (R L ) and approximate any
resistance added by the circuit board (R PCB ). We found the
inductor ’s nominal resistance in Section 2 (0.82 m ? ). In this
example, we approximate 0.50 m ? for the circuit board
resistance (R PCB ). With this information, Equation 30 can
be used to calculate the increase at the V DRP pin at full load:
(30)
+ 45 A @ (1.03 m W ) 0.50 m W ) @ 3.3 V V
+ 227 mV
R DRP can then be calculated from Equation 31:
http://onsemi.com
27
相关PDF资料 |
PDF描述 |
|---|---|
| NCP5378MNR2G | IC CTLR 1PH SYNC BUCK 32QFN |
| NCP5380AMNR2G | IC CTLR SYNC BUCK SGL 32QFN |
| NCP5381AMNR2G | IC BUCK CTLR 2/3/4PHASE 40-QFN |
| NCP5381MNR2G | IC CTLR BUCK 2/3/4PHASE 40-QFN |
| NCP5382MNR2G | IC BUCK CTLR 2-6PHASE 48-QFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| NCP5332ADWR2 | 功能描述:DC/DC 开关控制器 2 Phase Buck w/Gate RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| NCP5338MNR2G | 制造商:ON Semiconductor 功能描述:INTEGRATED DRIVER AND MOS - Tape and Reel 制造商:ON Semiconductor 功能描述:INTEGRATED DRIVER AND MOS - Cut TR (SOS) 制造商:ON Semiconductor 功能描述:REEL / INTEGRATED DRIVER AND MOS 制造商:ON Semiconductor 功能描述:Integrated Driver and MOSFET |
| NCP5351 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:4 A Synchronous Buck Power MOSFET Driver |
| NCP5351/D | 制造商:未知厂家 制造商全称:未知厂家 功能描述:4A Synchronous Buck Power Mosfet Driver |
| NCP5351D | 功能描述:功率驱动器IC 5V 4A Dual MOSFET RoHS:否 制造商:Micrel 产品:MOSFET Gate Drivers 类型:Low Cost High or Low Side MOSFET Driver 上升时间: 下降时间: 电源电压-最大:30 V 电源电压-最小:2.75 V 电源电流: 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Tube |
发布紧急采购，3分钟左右您将得到回复。