EEWORLDEEWORLDEEWORLD

Part Number

Search

UC3845TD

Description
HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER
CategoryPower/power management    The power supply circuit   
File Size165KB,15 Pages
ManufacturerSTMicroelectronics
Websitehttp://www.st.com/
Environmental Compliance
Download Datasheet Parametric Compare View All

UC3845TD Overview

HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER

UC3845TD Parametric

Parameter NameAttribute value
Is it Rohs certified?conform to
MakerSTMicroelectronics
Parts packaging codeSOIC
package instructionSOP,
Contacts8
Reach Compliance Codeunknow
ECCN codeEAR99
Analog Integrated Circuits - Other TypesSWITCHING CONTROLLER
control modeCURRENT-MODE
Control TechnologyPULSE WIDTH MODULATION
Maximum input voltage30 V
Minimum input voltage12 V
Nominal input voltage15 V
JESD-30 codeR-PDSO-G8
length4.9 mm
Number of functions1
Number of terminals8
Maximum output current1 A
Package body materialPLASTIC/EPOXY
encapsulated codeSOP
Package shapeRECTANGULAR
Package formSMALL OUTLINE
Certification statusNot Qualified
Maximum seat height1.75 mm
surface mountYES
Switch configurationSINGLE
Maximum switching frequency500 kHz
Terminal formGULL WING
Terminal pitch1.27 mm
Terminal locationDUAL
width3.9 mm
®
UC3842T UC3843T
UC3844T UC3845T
HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER
.
.
.
.
.
.
.
.
.
TRIMMED OSCILLATOR FOR PRECISE FRE-
QUENCY CONTROL
OSCILLATOR FREQUENCY GUARANTEED
AT 250kHz
CURRENT MODE OPERATION TO 500kHz
AUTOMATIC FEED FORWARD COMPENSA-
TION
LATCHING PWM FOR CYCLE-BY-CYCLE
CURRENT LIMITING
INTERNALLY TRIMMED REFERENCE WITH
UNDERVOLTAGE LOCKOUT
HIGH CURRENT TOTEM POLE OUTPUT
UNDERVOLTAGE LOCKOUT WITH HYSTER-
ESIS
LOW START-UP AND OPERATING CURRENT
Minidip
SO8
DESCRIPTION
The UC384XT family of control ICs provides the
necessary features to implement off-line or DC to
DC fixed frequency current mode control schemes
with a minimal external parts count. Internally imple-
mented circuits include a trimmed oscillator for pre-
cise DUTY CYCLE CONTROL under voltage lock-
out featuring start-up current less than 0.5mA, a pre-
cision reference trimmed for accuracy at the error
amp input, logic to insure latched operation, a PWM
comparator which also provides current limit control,
and a totem pole output stage designed to source
or sink high peak current. The output stage, suitable
for driving N-Channel MOSFETs, is low in the off-
state.
Differences between members of this family are the
under-voltage lockout thresholds and maximum duty
cycle ranges. The UC3842T and UC3844T have
UVLO thresholds of 16V (on) and 10V (off), ideally
suited to off-line applications The corresponding
thresholds for the UC3843T and UC3845T are 8.5 V
and 7.9 V. The UC3842T and UC3843T can operate
to duty cycles approaching 100%. A range of zero to
< 50 % is obtained by the UC3844T and UC3845T by
the addition of an internal toggle flip flop which blanks
the output off every other clock cycle.
BLOCK DIAGRAM
(toggle flip flop used only in UC3844T and UC3845T)
Vi
7
34V
GROUND
5
UVLO
S/R
5V
REF
INTERNAL
BIAS
VREF GOOD
LOGIC
RT/CT
4
OSC
ERROR AMP.
2R
R
1V
T
8
VREF
5V 50mA
2.50V
6
OUTPUT
VFB
COMP
CURRENT
SENSE
2
1
3
+
-
S
R
CURRENT
SENSE
COMPARATOR
D95IN331
PWM
LATCH
September 2001
1/15

UC3845TD Related Products

UC3845TD UC3842T UC3842TD UC3843TD UC3843T UC3844T UC3844TD UC3845T
Description HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER
Transplanting tslib, encountering ts_open: no such file or directory problem
When porting tslib, I encountered the problem of ts_open: no such file or directory. What is the cause and how to solve it?...
liangbo_01 Embedded System
The latest news on e-sports in 2007
There are six questions for undergraduate students in the e-sports competition....
zcx86ok MCU
A hotel receptionist
From EEWORLD cooperation group: arm linux fpga embedded 0 (49900581) Group owner: wangkjI am a hotel receptionist, and sometimes I help answer the phone at the service desk.Today I received a call tha...
IC_书童 Talking
Huang Zhiwei, University of South China 2013 Power supply circuit design based on TI
[i=s] This post was last edited by paulhyde on 2014-9-15 03:33 [/i] [b] Nanhua University Huang Zhiwei 2013 Power Circuit Design Based on TI [/b]...
黄智伟 Electronics Design Contest
After reading this, you will understand why people say: a daughter is her father’s lover in the previous life!
:lol[flash]http://www.tudou.com/v/IcxcLKAJKts/&resourceId=0_04_02_99/v.swf[/flash]...
yaoniming3k Talking
Does anyone have the matrix keyboard driver for ep9315? I have a problem with the keyboard driver. Thank you.
My keyboard driver does not have row scanning, no matter which interface the row is connected to, it will show the key of one interface. So only one row of key values can be printed. Thank you everyon...
jim200503 Embedded System

EEWorld
subscription
account

EEWorld
service
account

Automotive
development
circle

Robot
development
community

Index Files: 32  705  1973  938  2083  1  15  40  19  42 
Datasheet   0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Room 1530, 15th Floor, Building B, No. 18 Zhongguancun Street, Haidian District, Beijing Telephone: (010) 82350740 Postal Code: 100190
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved 京ICP证060456号 京ICP备10001474号-1 电信业务审批[2006]字第258号函 京公网安备 11010802033920号