- 您现在的位置：买卖IC网 > PDF目录1841 > MAX1858EEG+T (Maxim Integrated Products)IC REG CTRLR BUCK PWM VM 24-QSOP PDF资料下载
参数资料
| 型号： | MAX1858EEG+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 16/21页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM VM 24-QSOP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| PWM 型： | 电压模式 |
| 输出数： | 2 |
| 频率 - 最大： | 660kHz |
| 占空比： | 90% |
| 电源电压： | 4.75 V ~ 23 V |
| 降压： | 是 |
| 升压： | 无 |
| 回扫： | 无 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 24-SSOP（0.154"，3.90mm 宽） |
| 包装： | 带卷 (TR) |
Dual 180° Out-of-Phase PWM Step-Down
Controller with Power Sequencing and POR
GAIN = +V IN /V RAMP FOR
FREQUENCIES LOWER
P
DH
N
THAN NYQUIST
W
L
V OUT
L
COMP_
V C
g M_GROUP
M
DL
FB
N
LX
R ESR
C OUT
=
COMP_
g M_GROUP
FB
LX
R ESR
C OUT
R COMP_
C COMP_A
C COMP_B
V SET
R COMP_
C COMP_A
C COMP_B
V SET
Figure 7. Fixed-Frequency Voltage-Mode Control Loop
? R COMP has much higher impedance than C COMP_A .
This is true if, and only if, crossover occurs above
f Z_COMP_A . If this is true, C COMP_A can be ignored
(as a short to ground).
? R ESR is much higher impedance than C OUT . This is
true if, and only if, crossover occurs well after the out-
put capacitor ’ s ESR zero. If this is true, C OUT
? Unity-gain crossover must occur below 1/5th of the
switching frequency.
? For reasonable phase margin using type 1 compen-
sation, f CO must be larger than 5 ? f ESR .
Choose C COMP_A so that f Z_COMP_A equals half f LC
using the following equation:
becomes an insignificant part of the loop gain and can
be ignored (as a short to ground).
? C COMP_B is much higher impedance than R COMP
C COMP _ A =
2 × LC OUT
R COMP
and can be ignored (as an open circuit). This is true
if, and only if, crossover occurs far below f COMP_B .
Choose C COMP_B so that f COMP_B occurs at 3 times
f CO using the following equation:
The following loop-gain equation can be found by using
these previous approximations with Figure 7:
V IN V SET g M _ COMP × R COMP × R ESR
A L ? × ×
V RAMP V OUT sL
C COMP _ B =
1
2 π × ( 3 × f CO ) × R COMP
MOSFET Selection
Setting the loop gain to 1 and solving for the crossover
frequency yields:
The MAX1858 ’ s step-down controller drives two exter-
nal logic-level N-channel MOSFETs as the circuit switch
elements. The key selection parameters are:
× SET
f CO = GBW =
V IN
V RAMP
V
V OUT
? On-resistance (R DS(ON) )
? Maximum drain-to-source voltage (V DS(MAX) )
×
g M _ COMP × R COMP × R ESR
2 π × L
? Minimum threshold voltage (V TH(MIN) )
? Total gate charge (Q g )
? Reverse transfer capacitance (C RSS )
To ensure stability, select R COMP to meet the following
criteria:
? Power dissipation
16
______________________________________________________________________________________
相关PDF资料 |
PDF描述 |
|---|---|
| MAX1865TEEP+T | IC PWR SUPPLY CONTROLLER 20QSOP |
| MAX1873REEE+T | IC CNTRLR CHARGE LI+ 16-QSOP |
| MAX1874ETE+ | IC LI+ CHARGER DUAL-IN 16-TQFN |
| MAX1875AEEG+ | IC REG CTRLR BUCK PWM VM 24-QSOP |
| MAX1876EEG+T | IC REG CTRLR BUCK PWM VM 24-QSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1858EVKIT | 功能描述:DC/DC 开关控制器 Evaluation Kit for the MAX1858 MAX1875 MAX1876 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 |
| MAX185ACNG | 功能描述:模数转换器 - ADC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
| MAX185ACNG+ | 功能描述:模数转换器 - ADC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
| MAX185ACWG | 功能描述:模数转换器 - ADC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
| MAX185ACWG+ | 功能描述:模数转换器 - ADC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
发布紧急采购，3分钟左右您将得到回复。