Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF Download HTML

NCP1271 Datasheet(PDF) 4 Page - ON Semiconductor

Part No. NCP1271
Description  Soft−Skip Mode Standby PWM Controller with Adjustable Skip Level and External Latch
Download  19 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  ONSEMI [ON Semiconductor]
Homepage  http://www.onsemi.com
Logo ONSEMI - ON Semiconductor

NCP1271 Datasheet(HTML) 4 Page - ON Semiconductor

  NCP1271 Datasheet HTML 1Page - ON Semiconductor NCP1271 Datasheet HTML 2Page - ON Semiconductor NCP1271 Datasheet HTML 3Page - ON Semiconductor NCP1271 Datasheet HTML 4Page - ON Semiconductor NCP1271 Datasheet HTML 5Page - ON Semiconductor NCP1271 Datasheet HTML 6Page - ON Semiconductor NCP1271 Datasheet HTML 7Page - ON Semiconductor NCP1271 Datasheet HTML 8Page - ON Semiconductor NCP1271 Datasheet HTML 9Page - ON Semiconductor Next Button
Zoom Inzoom in Zoom Outzoom out
 4 / 19 page
background image
NCP1271
http://onsemi.com
4
Figure 2. Functional Block Diagram
LEB
Skip/ latch
CS
FB
7.5% Jittering
65, 100 kHz
Oscillator
130ms
delay
HV
S
R
Drv
Gnd
PWM
skip
OR
4.8 V
8 V
Max duty
R
S
= 80%
180 ns
0
&
+
+
+
+
soft−skip
8
2
3
4
1
6
5
Vss
V FB
latch−off, reset
when Vcc < 4V
jittered ramp
current source
I
V
short
circuit
fault
12.6/
5.8 V
9.1 V
turn off
UVLO
+
+
turn on internal bias
4.1 mA when Vcc > 0.6 V
driver:
+500 mA
/ −800 mA
10V
disable
soft
skip
skip
&
double
hiccup
S
Q
10V
10V
20V
V CS
V CC
V CC
0
100uA
0.2 mA when Vcc < 0.6 V
Soft start/ soft−skip
management
TLD
+
soft
start
2.85 V
1 / 3
13 us filter
1
0
skip
Rskip
4 ms/ 300 us
R CS
Rramp
(1V max)
16.7k
75.3k
V
/ 3
FB
V PWM
V FB
Q
R
Q
B2
Counter
Vskip = Rskip * Iskip or
Vskip = 1.2 V when pin 1 is opened
1
PIN FUNCTION DESCRIPTION
Pin No.
Symbol
Function
Description
1
Skip/latch
Skip Adjust or
Latchoff
A resistor to ground provides the adjustable standby skip level. Additionally, if this pin is
pulled higher than 8.0 V (typical), the controller latches off the drive.
2
FB
Feedback
An optocoupler collector pulls this pin low during regulation. If this voltage is less than
the Skip pin voltage, then the driver is pulled low and Soft−Skip mode is activated. If this
pin is open (>3 V) for more than 130 ms, then the controller is placed in a fault mode.
3
CS
Current Sense
This pin senses the primary current for PWM regulation. The maximum primary current
is limited to 1.0 V / RCS where RCS is the current sense resistor. Additionally, a ramp
resistor Rramp between the current sense node and this pin sets the compensation ramp
for improved stability.
4
Gnd
IC Ground
5
Drv
Driver Output
The NCP1271’s powerful output is capable of driving the gates of large Qg MOSFETs.
6
VCC
Supply Voltage
This is the positive supply of the device. The operating range is between 10 V (min) and
20 V (max) with a UVLO start threshold 12.6 V (typ).
8
HV
High Voltage
This pin provides (1) Lossless startup sequence (2) Double hiccup fault mode (3)
Memory for latch−off shutdown and (4) Device protection if VCC is shorted to GND.


Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19 


Datasheet Download

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Alldatasheet API   |   Link Exchange   |   Manufacturer List
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