参数资料
型号: LA5751
元件分类: 稳压器
英文描述: 3 A SWITCHING REGULATOR, 72 kHz SWITCHING FREQ-MAX, PZFM5
封装: TO-220, 5 PIN
文件页数: 4/5页
文件大小: 66K
代理商: LA5751
LA5751
No.A0945-4/5
Td =
=
= 28.2 msec
C
× V
i
1
× 0.62
22
Tss =
=
C
× VPWM × PWMduty
i
C
× 0.88 × PWMduty
22
A
1.5V
0.62V
PWM wave
PWMduty =
= 25%
VOUT + VF
VIN - Vsat + VF
Tss =
= 10msec
1
× 0.88V × 0.25
22
A
Description of Functional Settings
1.Start delay function
The SS pin has the internally-connected 22
A (typ) constant-current supply. When the voltage of SS pin exceeds the
threshold voltage, the regulator starts operation. As the threshold is 0.62V(typ), the start delay time can be calculated
as follows:
ex. For setting at 1
F
2.Soft start function
The internal PWM waveform has the voltage value as shown in the right.
If down-conversion from the voltage of VIN = 15V to 3.3V output to be made,
for example, the PWM-ON duty has the value as shown below.
(Note that calculation is made with Vsat = 1V and VF = 0.2V)
The output voltage of error amplifier, which is 3.3V, is the value with PWM = 25%, as calculated in the above
equation, so that this voltage is determined as follows:
Ver = (
VPWM) × PWMduty + VPWML = 0.88V × 0.25 + 0.62V = 0.84V
(
VPWM is the PWM amplitude value or 0.88V(typ) while VPWML is the lower limit voltage of PWM
waveform or 0.62V(typ))
SS pin and error amplifier output voltages are designed to prefer the lower voltages, so that VOUT will reach the
designed regulation voltage in timing when the SS pin voltage exceeds the error amplifier output. Therefore, the soft
strt time is calculated as follows:
For the set conditions of C = 1
F and PWMduty = 25%:
相关PDF资料
PDF描述
LA7019 2-CHANNEL, AUDIO/VIDEO SWITCH, PDIP6
LA7995M SWITCHED CAPACITOR CONVERTER, 65 kHz SWITCHING FREQ-MAX, PDSO14
LAS6380 9 A SWITCHING REGULATOR, 100 kHz SWITCHING FREQ-MAX, MBFM8
LAS6380P1 9 A SWITCHING REGULATOR, 100 kHz SWITCHING FREQ-MAX, PSFM9
LAS6381P1 9 A SWITCHING REGULATOR, 100 kHz SWITCHING FREQ-MAX, PSFM9
相关代理商/技术参数
参数描述
LA5751MP 制造商:SANYO 制造商全称:Sanyo Semicon Device 功能描述:Monolithic Linear IC Separately-excited Step-down Switching Regulator (3.3V)
LA5752 制造商:SANYO 制造商全称:Sanyo Semicon Device 功能描述:Monolithic Linear IC Separately-excited Step-down Switching Regulator (5V)
LA5752-E 功能描述:直流/直流开关调节器 RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
LA5752MP 制造商:SANYO 制造商全称:Sanyo Semicon Device 功能描述:Monolithic Linear IC Separately-excited Step-down Switching Regulator (5V)
LA5753 制造商:SANYO 制造商全称:Sanyo Semicon Device 功能描述:Monolithic Linear IC Separately-excited Step-down Switching Regulator (12V)