数据搜索系统,热门电子元器件搜索
  Chinese  ▼
ALLDATASHEETCN.COM

X  

CS51031YN8 数据表(PDF) 5 Page - Cherry Semiconductor Corporation

部件名 CS51031YN8
功能描述  Fast PFET Buck Controller Does Not Require Compensation
Download  8 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
制造商  CHERRY [Cherry Semiconductor Corporation]
网页  http://www.cherrycorp.com/
标志 CHERRY - Cherry Semiconductor Corporation

CS51031YN8 数据表(HTML) 5 Page - Cherry Semiconductor Corporation

  CS51031YN8 Datasheet HTML 1Page - Cherry Semiconductor Corporation CS51031YN8 Datasheet HTML 2Page - Cherry Semiconductor Corporation CS51031YN8 Datasheet HTML 3Page - Cherry Semiconductor Corporation CS51031YN8 Datasheet HTML 4Page - Cherry Semiconductor Corporation CS51031YN8 Datasheet HTML 5Page - Cherry Semiconductor Corporation CS51031YN8 Datasheet HTML 6Page - Cherry Semiconductor Corporation CS51031YN8 Datasheet HTML 7Page - Cherry Semiconductor Corporation CS51031YN8 Datasheet HTML 8Page - Cherry Semiconductor Corporation  
Zoom Inzoom in Zoom Outzoom out
 5 / 8 page
background image
5
2.4V, the CS charge sense comparator (A4) sets the VFB
comparator reference to 1.25V completing the startup
cycle.
Lossless Short Circuit Protection
The CS51031 has ÒlosslessÓ short circuit protection since
there is no current sense resistor required. When the volt-
age at the CS pin (the fault timing capacitor voltage ) reach-
es 2.5V during startup, the fault timing circuitry is enabled.
During normal operation the CS voltage is 2.6V. During a
short circuit or a transient condition, the output voltage
moves lower and the voltage at VFB drops. If VFB drops
below 1.15V, the output of the fault comparator goes high
and the CS51031 goes into a fast discharge mode. The fault
timing capacitor, CS, discharges to 2.4V. If the VFB voltage
is still below 1.15V when the CS pin reaches 2.4V, a valid
fault condition has been detected. The slow discharge
comparator output goes high and enables gate G5 which
sets the slow discharge flip flop. The Vgate flip flop resets
and the output switch is turned off. The fault timing
capacitor is slowly discharged to 1.5V. The CS51031 then
enters a normal startup routine. If the fault is still present
when the fault timing capacitor voltage reaches 2.5V, the
fast and slow discharge cycles repeat as shown in figure 2.
If the VFB voltage is above 1.15V when CS reaches 2.4V a
fault condition is not detected, normal operation resumes
and CS charges back to 2.6V. This reduces the chance of
erroneously detecting a load transient as a fault condition.
Figure 2. Voltage on start capacitor (VGS ), the gate (VGATE ), and in the
feedback loop (VFB), during startup, normal and fault conditions.
Buck Regulator Operation
Figure 3. Buck regulator block diagram.
A block diagram of a typical buck regulator is shown in
Figure 3. If we assume that the output transistor is initially
off, and the system is in discontinuous operation, the
inductor current IL is zero and the output voltage is at its
nominal value. The current drawn by the load is supplied
by the output capacitor CO . When the voltage across CO
drops below the threshold established by the feedback
resistors R1 and R2 and the reference voltage VREF, the
power transistor Q1 switches on and current flows through
the inductor to the output. The inductor current rises at a
rate determined by (VIN-VOUT)/L. The duty cycle (or ÒonÓ
time) for the CS51031 is limited to 80%. If output voltage
remains higher than nominal during the entire COSC
change time, the Q1 does not turn on, skipping the pulse.
Control
Feedback
VIN
L
D1
R1
R2
RLOAD
CO
Q1
CIN
2.5V
0V
FAULT
NORMAL OPERATION
START
TSTART
td1
td2
tFAULT
tRESTART
tFAULT
S2
S2
S2
S3
S3
S3
S3
S1
S1
S1
2.6V
2.4V
1.5V
0V
1.25V
1.15V
VCS
VGATE
VFB
Circuit Description: continued
Applications Information
Specifications 12V to 5V, 3A Buck converter
VIN = 12V ±20% (i.e. 14.4V max., 12Vnom., 9.6V min.)
VOUT = 5V ±2%
IOUT = 0.3A to 3A
Output ripple voltage < 50mV max.
Efficiency > 80%
fSW = 200kHz
1) Duty cycle estimates
Since the maximum duty cycle D, of the CS51031 is limited
to 80% min., it is necessary to estimate the duty cycle for
the various input conditions over the complete operating
range.
The duty cycle for a buck regulator operating in a continu-
ous conduction mode is given by:
D =
VOUT + VF
VIN - VSAT
CS51031 Design Example


类似零件编号 - CS51031YN8

制造商部件名数据表功能描述
logo
ON Semiconductor
CS51031YD8 ONSEMI-CS51031YD8 Datasheet
86Kb / 12P
   Fast PFET Buck Controller
December, 2001 ??Rev. 9
CS51031YD8 ONSEMI-CS51031YD8 Datasheet
95Kb / 10P
   Fast P?묬h FET Buck Controller
October, 2005 ??Rev. 11
CS51031YD8 ONSEMI-CS51031YD8 Datasheet
100Kb / 10P
   Fast P?묬h FET Buck Controller
October, 2005 ??Rev. 11
CS51031YD8G ONSEMI-CS51031YD8G Datasheet
95Kb / 10P
   Fast P?묬h FET Buck Controller
October, 2005 ??Rev. 11
CS51031YD8G ONSEMI-CS51031YD8G Datasheet
100Kb / 10P
   Fast P?묬h FET Buck Controller
October, 2005 ??Rev. 11
More results

类似说明 - CS51031YN8

制造商部件名数据表功能描述
logo
Cherry Semiconductor Co...
CS51033 CHERRY-CS51033 Datasheet
159Kb / 8P
   Fast PFET Buck Controller Does Not Require Compensation
logo
HTC Korea TAEJIN Techno...
LM51031 HTC-LM51031 Datasheet
273Kb / 9P
   Fast PFET Buck Controller
logo
ON Semiconductor
CS51031 ONSEMI-CS51031 Datasheet
86Kb / 12P
   Fast PFET Buck Controller
December, 2001 ??Rev. 9
CS51033 ONSEMI-CS51033 Datasheet
86Kb / 12P
   Fast PFET Buck Controller
October, 2002 ??Rev. 8
logo
Texas Instruments
LM3485 TI-LM3485_15 Datasheet
1Mb / 24P
[Old version datasheet]   Hysteretic PFET Buck Controller
logo
National Semiconductor ...
LM3485 NSC-LM3485 Datasheet
369Kb / 15P
   Hysteretic PFET Buck Controller
logo
Texas Instruments
LM3485 TI1-LM3485_14 Datasheet
1,023Kb / 22P
[Old version datasheet]   Hysteretic PFET Buck Controller
LM3475 TI1-LM3475_14 Datasheet
1Mb / 21P
[Old version datasheet]   Hysteretic PFET Buck Controller
LM3485 TI1-LM3485_16 Datasheet
1Mb / 28P
[Old version datasheet]   Hysteretic PFET Buck Controller
logo
National Semiconductor ...
LM3475 NSC-LM3475 Datasheet
305Kb / 14P
   Hysteretic PFET Buck Controller
More results


Html Pages

1 2 3 4 5 6 7 8


数据表 下载

Go To PDF Page


链接网址




隐私政策
ALLDATASHEETCN.COM
ALLDATASHEET是否为您带来帮助?  [ DONATE ] 

关于 Alldatasheet   |   广告服务   |   联系我们   |   隐私政策   |   链接交换   |   制造商名单
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com