参数资料
型号: KIT33702DWBEVB
厂商: Freescale Semiconductor
文件页数: 31/39页
文件大小: 0K
描述: KIT FEATURES THE MC34701
标准包装: 1
主要目的: DC/DC,LDO 步降
输出及类型: 2,非隔离
输入电压: 2.8 ~ 6V
稳压器拓扑结构: 降压
频率 - 开关: 300kHz
板类型: 完全填充
已供物品: 板,软件
已用 IC / 零件: MC34702
相关产品: MC34702EKR2CT-ND - IC POWER SUPPLY MCU 3A 32-SOIC
MC34702EKR2TR-ND - IC POWER SUPPLY MCU 3A 32-SOIC
MC34702EK-ND - IC POWER SUPPLY MCU 3A 32-SOIC
TYPICAL APPLICATIONS
.
R2 = V Ref ? -----------------------------------------------------------------------------------------
? V O + I O ? R L ? – V Ref V O – V Ref
-------------------------------------------------------- + --------------------------
G ain
[dB]
20
fLC
R4 R1
1
0
fz(c)
f BW
fz(E SR) fp (FF)
Where V Ref is the buck regulator reference voltage ?
(V Ref = 0.8V typ.) at the INV pin, ?
V O is the selected output voltage, ?
I O is the output load current, ?
R L is the DC resistance of the inductor L.
-20
-40
-180
fp(c)
It is apparent that the buck regulator output voltage is
affected by the voltage drop caused by the inductor serial
resistance and the regulator output current. In those
applications which do not require precise output voltage,
setting the formula for calculating selected output voltage can
be simplified as follows:
R2 = V Ref ? ----------------------------------------------------------------
? V O – V Ref ? ? ---------------------------
Pha se
[Deg.]
1
? R1 + R4 ?
R1 ? R4
V LDO = V Ref ? ? ? ? ?
R U
-2 70
-3 60
? m
Linear Regulator Output Voltage
The output voltage of the linear regulator (LDO) can be set
by a simple resistor divider according to the following formula:
1 + -------
R L
1.0
10
100
10 00
10000
f z ? ESR ? = ----------------------------
Frequency [k Hz ]
Figure 30. Buck Control Loop Bode Plot
The frequency of the zero created by the ESR of the output
capacitor C O is calculated as:
1
2 ? C O ESR
Where C O is the value of the buck regulator output
capacitor, and ESR is the equivalent series resistance of the
output capacitor.
The frequency of the compensating network pole can be
calculated as follows:
Where V Ref is the linear regulator reference voltage ?
(V Ref = 0.8V typ.) at the LFB pin, ?
V LDO is the LDO selected output voltage, ?
R U is the “upper” resistor of the LDO resistor divider, ?
R L is the “lower” resistor of the LDO resistor divider.
Figure 31 describes the 34702 linear regulator circuit with
the resistor divider R U , R L setting the output voltage V LDO .
2.8 V to 6. 0 V Input
MC34701
VIN1
f p ? c ? = -------------------------------------------
2 ? C2 ---------------------------
1
R1R3
? R1 + R3 ?
The well designed and compensated buck regulator
should yield at least 45 deg. phase margin ? m of its overall
LDRV
CS
LDO
LFB
LCMP
RS
RU
RL
VLDO
CLDO
loop as depicted in the Figure 30 , page 31 .
Selecting Buck Regulator Output Voltage
The 34702 buck regulator output voltage can be set by
selecting the right value of the resistors R1, R2 and R4, and
can be determined from the following formula (see Figure 29 ,
LDO
Compensation
Figure 31. 34702 Linear Regulator Circuit
page 30 for the component references):
34702
Analog Integrated Circuit Device Data ?
Freescale Semiconductor
31
相关PDF资料
PDF描述
TC426EOA IC MOSFET DVR 1.5A DUAL HS 8SOIC
TC1427COA IC MOSFET DVR 1.2A DUAL HS 8SOIC
TC1426CPA IC MOSFET DVR 1.2A DUAL HS 8DIP
TC4428AEOA IC MOSFET DVR 1.5A DUAL HS 8SOIC
TC1427CPA IC MOSFET DVR 1.2A DUAL HS 8DIP
相关代理商/技术参数
参数描述
KIT33730EKEVBE 功能描述:电源管理IC开发工具 SWITCH MODE PWR SUP RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
KIT33742DWEVB 功能描述:网络开发工具 SBC WITH EHSCAN RoHS:否 制造商:Rabbit Semiconductor 产品:Development Kits 类型:Ethernet to Wi-Fi Bridges 工具用于评估:RCM6600W 数据速率:20 Mbps, 40 Mbps 接口类型:802.11 b/g, Ethernet 工作电源电压:3.3 V
KIT3376MMA7330L 功能描述:加速传感器开发工具 XYZ-AXIS ANALOG ACCELERO RoHS:否 制造商:Murata 工具用于评估:SCA3100-D04 加速:2 g 传感轴:Triple Axis 接口类型:SPI 工作电压:3.3 V
KIT3376MMA7331L 功能描述:加速传感器开发工具 3-AXIS ANALOG OUT 4g /12g Dev Kit RoHS:否 制造商:Murata 工具用于评估:SCA3100-D04 加速:2 g 传感轴:Triple Axis 接口类型:SPI 工作电压:3.3 V
KIT3376MMA7331LC 功能描述:加速传感器开发工具 3AXIS Angl Accelero Eval Kit RoHS:否 制造商:Murata 工具用于评估:SCA3100-D04 加速:2 g 传感轴:Triple Axis 接口类型:SPI 工作电压:3.3 V