參數(shù)資料
型號(hào): L7981ATR
廠商: STMICROELECTRONICS
元件分類: 穩(wěn)壓器
英文描述: SWITCHING REGULATOR, DSO8
封裝: 3 X 3 MM, 1.08 MM HEIGHT, ROHS COMPLIANT, HSOP-8
文件頁(yè)數(shù): 4/44頁(yè)
文件大小: 1315K
代理商: L7981ATR
Functional description
L7981
12/44
Doc ID 15182 Rev 3
5.3
Error amplifier and compensation
The error amplifier (E/A) provides the error signal to be compared with the sawtooth to
perform the pulse width modulation. Its non-inverting input is internally connected to a 0.6 V
voltage reference, while its inverting input (FB) and output (COMP) are externally available
for feedback and frequency compensation. In this device the error amplifier is a voltage
mode operational amplifier so with high DC gain and low output impedance.
The uncompensated error amplifier characteristics are the following:
In continuos conduction mode (CCM), the transfer function of the power section has two
poles due to the LC filter and one zero due to the ESR of the output capacitor. Different
kinds of compensation networks can be used depending on the ESR value of the output
capacitor. In case the zero introduced by the output capacitor helps to compensate the
double pole of the LC filter a type II compensation network can be used. Otherwise, a type
III compensation network has to be used (see Chapter 6.4 for details about the
compensation network selection).
Anyway the methodology to compensate the loop is to introduce zeros to obtain a safe
phase margin.
Table 5.
Uncompensated error amplifier characteristics
Low frequency gain
100dB
GBWP
4.5MHz
Slew rate
7V/
μs
Output voltage swing
0 to 3.3V
Maximum source/sink current
17mA/25mA
相關(guān)PDF資料
PDF描述
L7981TR SWITCHING REGULATOR, DSO8
L8219LP STEPPER MOTOR CONTROLLER, 2.5 A, PDSO28
L8219P STEPPER MOTOR CONTROLLER, 2.5 A, PDSO36
L8229 STEPPER MOTOR CONTROLLER, 1.5 A, PDSO24
L9484 SWITCHING REGULATOR, 460 kHz SWITCHING FREQ-MAX, PSFM8
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
L7981ATR/BLK 制造商:STMicroelectronics 功能描述:3 A STEP-DOWN SWITCHING REGULATO - Tape and Reel 制造商:STMicroelectronics 功能描述:STMicroelectronics L7981ATR/BLK Interface Misc
L7981TR 功能描述:直流/直流開(kāi)關(guān)調(diào)節(jié)器 3A DC 4.5 V to 28 V Adj 0.6V 250 kHz RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開(kāi)關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5
L7983 制造商:Leviton Manufacturing Co 功能描述:
L7985 功能描述:線性穩(wěn)壓器 - 標(biāo)準(zhǔn) 2A Step Down REG 4.5V to 38V 250 KHz RoHS:否 制造商:STMicroelectronics 輸出類型: 極性: 輸出電壓:1.8 V 輸出電流:150 mA 負(fù)載調(diào)節(jié): 最大輸入電壓:5.5 V 線路調(diào)整率: 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOT-323-5L
L7985A 功能描述:直流/直流開(kāi)關(guān)調(diào)節(jié)器 2A DC 4.5V to 38V 250 KHz Step-Down RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開(kāi)關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5