參數(shù)資料
型號(hào): CS3845GDR8
廠商: ZF Electronics Corporation
英文描述: Current Mode PWM Control Circuit with 50% Max Duty Cycle
中文描述: 電流模式PWM控制電路的最大占空比為50%
文件頁(yè)數(shù): 4/6頁(yè)
文件大?。?/td> 156K
代理商: CS3845GDR8
4
C
Undervoltage Lockout
During Undervoltage Lockout (Figure 1), the output driv-
er is biased to sink minor amounts of current. The output
should be shunted to ground with a resistor to prevent
activating the power switch with extraneous leakage cur-
rents.
PWM Waveform
To generate the PWM waveform, the control voltage from
the error amplifier is compared to a current sense signal
which represents the peak output inductor current (Figure
2). An increase in V
CC
causes the inductor current slope to
increase, thus reducing the duty cycle. This is an inherent
feed-forward characteristic of current mode control, since
the control voltage does not have to change during
changes of input supply voltage.
When the power supply sees a sudden large output cur-
rent increase, the control voltage will increase allowing
the duty cycle to momentarily increase. Since the duty
cycle tends to exceed the maximum allowed to prevent
transformer saturation in some power supplies, the inter-
nal oscillator waveform provides the maximum duty cycle
clamp as programmed by the selection of OSC compo-
nents.
Circuit Description
Test Circuit Open Loop Laboratory Test Fixture
V
REF
V
CC
V
OUT
1k
1W
0.1
μ
F
0.1
μ
F
V
REF
V
CC
V
OUT
Gnd
V
FB
Sense
OSC
COMP
5k
100k
4.7k
1k
Error Amp
Adjust
4.7k
Sense
Adjust
R
T
2N2222
C
T
Gnd
A
V
CC
V
ON
16V 8.4V
V
OFF
10V 7.6V
CSX844
CSX845
ON/OFF Command
to reset of IC
<15mA
<1mA
V
ON
V
OFF
I
CC
V
CC
Figure 1: Startup voltage for CSX844 and CSX845.
相關(guān)PDF資料
PDF描述
CS3845GDW16 Current Mode PWM Control Circuit with 50% Max Duty Cycle
CS3845GDWR16 Current Mode PWM Control Circuit with 50% Max Duty Cycle
CS2844 IC CONV AC/DC 24V 50MA SIP10
CS2845LN8 IC AC/DC CONV 5V 100MA SIP10
CS3845GN8 Current Mode PWM Control Circuit with 50% Max Duty Cycle
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
CS3845GDW16 制造商:CHERRY 制造商全稱:CHERRY 功能描述:Current Mode PWM Control Circuit with 50% Max Duty Cycle
CS3845GDWR16 制造商:CHERRY 制造商全稱:CHERRY 功能描述:Current Mode PWM Control Circuit with 50% Max Duty Cycle
CS3845GN8 制造商:Rochester Electronics LLC 功能描述:- Bulk
CS-3845N8 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Current-Mode SMPS Controller
CS-386 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Automotive Voltage Regulator