Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.NET

X  

UCC1858 Datasheet(PDF) 4 Page - Texas Instruments

Part # UCC1858
Description  High Efficiency, High Power Factor Preregulator
Download  12 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  TI [Texas Instruments]
Direct Link  http://www.ti.com
Logo TI - Texas Instruments

UCC1858 Datasheet(HTML) 4 Page - Texas Instruments

  UCC1858 Datasheet HTML 1Page - Texas Instruments UCC1858 Datasheet HTML 2Page - Texas Instruments UCC1858 Datasheet HTML 3Page - Texas Instruments UCC1858 Datasheet HTML 4Page - Texas Instruments UCC1858 Datasheet HTML 5Page - Texas Instruments UCC1858 Datasheet HTML 6Page - Texas Instruments UCC1858 Datasheet HTML 7Page - Texas Instruments UCC1858 Datasheet HTML 8Page - Texas Instruments UCC1858 Datasheet HTML 9Page - Texas Instruments Next Button
Zoom Inzoom in Zoom Outzoom out
 4 / 12 page
background image
4
UCC1858
UCC2858
UCC3858
PIN DESCRIPTIONS
CA–: (Current Amplifier Inverting Input) This input and
the non-inverting input MOUT remain functional down to
GND.
CAO: (Current Amplifier Ouput) Output of a wide band-
width amplifier that senses line current and commands
the pulse width modulator (PWM) to force the correct cur-
rent. This output can swing close to GND, allowing the
PWM to force zero duty cycle when necessary.
CRMS: (RMS Measurement Capacitor) A capacitor con-
nected between CRMS and GND enables averaging of
the AC line voltage over a half cycle. IAC current is inter-
nally mirrored to provide charging current for CRMS.
CT: (Oscillator Timing Capacitor) A capacitor from CT to
GND will set the free-running PWM oscillator frequency
according to:
f
RC
TT
=
0 814
.
FBL: (Frequency Foldback Level Select) Selects the level
of the voltage error amplifier output at which frequency
foldback begins. A chip shutdown can be attained by
bringing the foldback level pin to below 0.5V.
FBM: (Minimum Frequency Reference) A resistor be-
tween this pin and VREF is used to set the minimum fre-
quency during foldback mode. Once the value of RT and
CT are determined, use
R
Cf
R
FBM
TMIN
T
=
0 857
.
to find the value of RFBM which will set the minimum
foldback frequency to fMIN. This pin also incorporates a
foldback override which enables the part to return quickly
to normal operating mode when the load comes back up.
To override foldback mode, force this pin below 1.5V with
an open collector.
GND: (Ground) All voltages measured with respect to
ground. VDD and VREF should be bypassed directly to
GND with a 0.1
µF or larger ceramic capacitor. The timing
capacitor discharge current also returns to this pin, so
the lead from CT to GND should be as short and direct
as possible.
IAC: (Input AC Current) This input to the analog multiplier
is a current. The multiplier is tailored for very low distor-
tion from this current input (IIAC) to MOUT. Requires
some bypassing to GND for noise filtering (<470pF).
MOUT: (Multiplier Output) The output of the analog multi-
plier and the non-inverting input of the current amplifier
are connected together at MOUT. As the multiplier output
is a current, this is a high impedance input so the ampli-
fier can be configured as a differential amplifier to reject
ground noise. The voltage at this pin is also used to im-
plement peak current limiting.
OUT: (Gate Drive Output) The output of the PWM is a to-
tem pole MOSFET gate driver. A series gate resistor of
at least 5
Ω is recommended to prevent interaction be-
tween the gate impedance and the output driver that
might cause the gate drive to overshoot excessively.
RT: (Oscillator Timing Resistor) A resistor from RT to
GND is used to program oscillator discharge current.
SYNC: (Oscillator Synchronization Input) Allows the PFC
to be synchronized to a trailing edge modulator in the
DC-DC stage. A synchronization pulse can be generated
from the positive output edge of the downstream regula-
tor and applied to this pin. The internal clock is reset
(charged up) on the rising edge of the SYNC input.
VA–: (Voltage Amplifier Inverting Input) This pin is nor-
mally connected to the boost converter output through a
divider network. It also is an input to the overvoltage
comparator where by the output is terminated if this pin’s
voltage exceeds 3.15V.
VAO:
(Voltage
Amplifier
Output)
Output
of
the
transconductance amplifier that regulates output voltage.
The voltage amplifier output is internally limited to ap-
proximately 6V for power limiting. It is also used to deter-
mine the frequency foldback mode. Compensation
network is connected from this pin to GND.
ELECTRICAL CHARACTERISTICS: Unless otherwise stated, these specifications apply for TA = 0°C to 70°C for the
UCC3858, –40°C to +85°C for the UCC2858, and –55°C to +150°C for the UCC1858, VVDD = 12V, RT = 24k, CT = 330pF, RFBM =
96k, IIAC = 100µA, TA = TJ.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Gate Driver
Pull Up Resistance
IOUT = 100mA
7
Pull Down Resistance
IOUT = –100mA
3.5
Output Rise Time
CLOAD = 1nF, RS = 10Ω
25
ns
Output Fall Time
CLOAD = 1nF, RS = 10Ω
20
ns
Note1: M
OUT current with contributions form CA+ and peak limit level shift subtracted out.


Similar Part No. - UCC1858

ManufacturerPart #DatasheetDescription
logo
Texas Instruments
UCC1858 TI1-UCC1858 Datasheet
369Kb / 13P
[Old version datasheet]   High Efficiency, High Power Factor Preregulator
UCC1858 TI1-UCC1858_08 Datasheet
369Kb / 13P
[Old version datasheet]   High Efficiency, High Power Factor Preregulator
More results

Similar Description - UCC1858

ManufacturerPart #DatasheetDescription
logo
Texas Instruments
UCC1858 TI1-UCC1858_08 Datasheet
369Kb / 13P
[Old version datasheet]   High Efficiency, High Power Factor Preregulator
UC2853A TI-UC2853A Datasheet
411Kb / 10P
[Old version datasheet]   High Power Factor Preregulator
UC1854 TI-UC1854 Datasheet
281Kb / 9P
[Old version datasheet]   High Power Factor Preregulator
UC2853A TI1-UC2853A_16 Datasheet
854Kb / 9P
[Old version datasheet]   High Power Factor Preregulator
UC1854 TI-UC1854_08 Datasheet
473Kb / 13P
[Old version datasheet]   High Power Factor Preregulator
logo
TOKO, Inc
TK83854 TOKO-TK83854 Datasheet
109Kb / 12P
   HIGH POWER FACTOR PREREGULATOR
logo
Texas Instruments
UC1853 TI1-UC1853_08 Datasheet
401Kb / 10P
[Old version datasheet]   High Power Factor Preregulator
UC1852 TI-UC1852 Datasheet
210Kb / 6P
[Old version datasheet]   High Power-Factor Preregulator
UC1852 TI-UC1852_V01 Datasheet
802Kb / 10P
[Old version datasheet]   High Power-Factor Preregulator
UC3854N-F TI1-UC3854N-F Datasheet
312Kb / 12P
[Old version datasheet]   High Power Factor Preregulator
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12


Datasheet Download

Go To PDF Page


Link URL




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

About Alldatasheet   |   Advertisement   |   Contact us   |   Privacy Policy   |   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
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com