TL2843B-Q1 Datasheet, PDF (1/16 Pages) Texas Instruments – HIGH-PERFORMANCE CURRENT-MODE PWM CONTROLLER

TL2843B-Q1
www.ti.com
SLVSAE2A – JULY 2010 – REVISED FEBRUARY 2012
HIGH-PERFORMANCE CURRENT-MODE PWM CONTROLLER
Check for Samples: TL2843B-Q1
FEATURES
1
• Qualified for Automotive Applications
• Low Start-Up Current (<0.5 mA)
• Trimmed Oscillator Discharge Current
• Current Mode Operation to 500 kHz
• Automatic Feed-Forward Compensation
• Latching PWM for Cycle-by-Cycle Current
Limiting
• Internally Trimmed Reference With
Undervoltage Lockout
• High-Current Totem-Pole Output Undervoltage
Lockout With Hysteresis
• Double-Pulse Suppression
DESCRIPTION
The TL284xB series of control integrated circuits provide the features that are necessary to implement off-line or
dc-to-dc fixed-frequency current-mode control schemes, with a minimum number of external components.
Internally implemented circuits include an undervoltage lockout (UVLO) and a precision reference that is trimmed
for accuracy at the error amplifier input. Other internal circuits include logic to ensure latched operation, a
pulse-width modulation (PWM) comparator that 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
when it is in the off state.
The TL284xB series are pin compatible with the standard TL284x with the following improvements. The start-up
current is specified to be 0.5 mA (max), while the oscillator discharge current is trimmed to 8.3 mA (typ). In
addition, during undervoltage lockout conditions, the output has a maximum saturation voltage of 1.2 V while
sinking 10 mA (V_CC = 5 V).
Major differences between members of these series are the UVLO thresholds and maximum duty-cycle ranges.
Typical UVLO thresholds of 16 V (on) and 10 V (off) on the TL2842B and TL2844B devices make them ideally
suited to off-line applications. The corresponding typical thresholds for the TL2843B and TL2845B devices are
8.4 V (on) and 7.6 V (off). The TL2842B and TL2843B devices can operate to duty cycles approaching 100%. A
duty-cycle range of 0% to 50% is obtained by the TL2844B and TL2845B by the addition of an internal toggle
flip-flop, which blanks the output off every other clock cycle.The TL284xB-series devices are characterized for
operation from –40°C to 125°C.
T_A
–40°C to 125°C SOIC – D
Table 1. ORDERING INFORMATION⁽¹⁾
PACKAGE ⁽²⁾
ORDERABLE PART NUMBER
TL2842BQDRQ1
Reel of 2500
TL2843BQDRQ1
TL2844BQDRQ1
TL2845BQDRQ1
TOP-SIDE MARKING
Product Preview
TL2843BQ
Product Preview
Product Preview
(1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI
web site at www.ti.com.
(2) Package drawings, thermal data, and symbolization are available at www.ti.com/packaging.
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2010–2012, Texas Instruments Incorporated