- 您現在的位置：買賣IC網 > PDF目錄382717 > UC1573N 8-bit MCU for automotive with Flash or ROM, 10-bit ADC, 5 timers, SPI, LINSCI", active CAN PDF資料下載
參數資料
| 型號： | UC1573N |
| 英文描述： | 8-bit MCU for automotive with Flash or ROM, 10-bit ADC, 5 timers, SPI, LINSCI", active CAN |
| 中文描述： | 模擬IC |
| 文件頁數： | 4/8頁 |
| 文件大?。?/td> | 208K |
| 代理商： | UC1573N |
The Block Diagram shows a step-up switching regulator
utilizing the UC2577. The regulator produces an output
voltage higher than the input voltage. The UC2577 turns
its switch on and off at a fixed frequency of 52kHz, thus
storing energy in the inductor (L). When the NPN switch
is on, the inductor current is charged at a rate of VIN/L.
When the switch is off, the voltage at the SWITCH termi-
nal of the inductor rises above VIN, discharging the
stored current through the output diode (D) into the out-
put capacitor (C
OUT
) at a rate of (V
OUT
- VIN)/L. The en-
ergy stored in the inductor is thus transferred to the
output.
The output voltage is controlled by the amount of energy
transferred, which is controlled by modulating the peak
inductor current. This modulation is accomplished by
feeding a portion of the output voltage to an error ampli-
fier which amplifies the difference between the feedback
voltage and an internal 1.23V precision reference volt-
age. The output of the error amplifier is then compared to
a voltage proportional to the switch current, or the induc-
tor current, during the switch on time. A comparator ter-
minates the switch on time when the two voltages are
equal and thus controls the peak switch current to main-
tain a constant output voltage. Figure 2 shows voltage
and current waveforms for the circuit. Formulas for calcu-
lation are shown in Figure 3.
STEP-UP REGULATOR DESIGN PROCEDURE
Refer to the Block Diagram
Given:
V
INmin
= Minimum input supply voltage
V
OUT
= Regulated output voltage
UC2577-ADJ
Step-up (Boost) Regulator
Duty Cycle
D
V
OUT
+
V
F
V
IN
V
OUT
+
V
F
V
SAT
≈
V
OUT
V
IN
V
OUT
Avg. Inductor
Current
I
IND(AVG)
I
LOAD
1
D
Inductor
Current Ripple
I
IND
V
IN
V
SAT
L
D
52,000
Peak Inductor
Current
I
IND(PK)
I
LOAD
1
D
+
I
IND
2
Peak Switch
Current
I
SW(PK)
I
LOAD
1
D
+
I
IND
2
Switch Voltage
when Off
V
SW(OFF)
V
OUT
+ V
F
Diode Reverse
Voltage
V
R
V
OUT
- V
SAT
Avg. Diode
Current
I
D(AVG)
I
LOAD
Peak Diode
Current
I
D(PK)
I
LOAD
1
D
+
I
IND
2
.
Power
Dissipation
P
D
0.25
I
LOAD
1
D
2
D
+
I
LOAD
D
V
IN
50
(
1
D
)
V
F
= Forward Biased Diode Voltage, I
LOAD
= Output Load
Figure 2. Step-up Regulator Waveforms
First, determine if the UC2577 can provide these values
of V
OUT
and I
LOADmax
when operating with the minimum
value of V
IN
. The upper limits for V
OUT
and I
LOADmax
are
given by the following equations.
V
OUT
≤
60V and
V
OUT
≤
10
V
INmin
I
LOADmax
≤
2.1A
V
INmin
V
OUT
These limits must be greater than or equal to the values
specified in this application.
1. Output Voltage Section
Resistors R1 and R2 are used to select the desired out-
put voltage. These resistors form a voltage divider and
present a portion of the output voltage to the error ampli-
fier which compares it to an internal 1.23V reference. Se-
lect R1 and R2 such that:
R1
R2
=
V
OUT
1.23V
1
Figure 3. Step-up Regulator Formulas
APPLICATIONS INFORMATION
4
Powered by ICminer.com Electronic-Library Service CopyRight 2003
相關PDF資料 |
PDF描述 |
|---|---|
| UC2573D | ISO HIGH SIDE SMART POWER SOLID STATE RELAY |
| UC2573DTR | ISO HIGH SIDE SMART POWER SOLID STATE RELAY |
| UC2573J | ISO HIGH SIDE SMART POWER SOLID STATE RELAY |
| UC2573N | Voltage-Mode SMPS Controller |
| UC2577T-12 | Current-Mode SMPS Controller |
相關代理商/技術參數 |
參數描述 |
|---|---|
| UC15-8-20DD | 制造商:Takachi Electric Industrial 功能描述:UC15-8-20DD |
| UC1584 | 制造商:TI 制造商全稱:Texas Instruments 功能描述:Secondary Side Synchronous Post Regulator |
| UC1584J | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC |
| UC-1602ASWCG01 | 制造商:WISECHIP SEMICONDUCTOR INC 功能描述:2.26" 16 x 2 Parallel/I2C/Serial White OLED LCD 制造商:WISECHIP SEMICONDUCTOR INC 功能描述:2.26" 16x2 White OLED LCD |
| UC-1602ASYCG01 | 制造商:WISECHIP SEMICONDUCTOR INC 功能描述:2.26" (16 x 2) Yellow OLED LCD (68.50 17.50 2.00) 制造商:WISECHIP SEMICONDUCTOR INC 功能描述:2.26" 16x2 Yellow OLED LCD |
發布緊急采購，3分鐘左右您將得到回復。