Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - voltage regulators - DC DC switch controllers SOIC 24

DELAY

GND

VCC

REF

SYNC

CSA−

CSA+

CSAO

CEA−

VEA−

VEA+

RAMPCEA+

CEAOVEAO

PULL

PGND

PUSH

SRC

BUCK

V+

DELAY

REF

UVLO

INHBT

OSC

500 kHz

MAX

6 5

Current Sense

Amplifier

ILIM Comparator

+3 V

Current Error

Amplifier

PWM Comparator0.7 V

Flying

Driver

Push/Pull

Drivers

OSC

UVLO

Voltage Error

Amplifier

UC2827-1, UC2827-2

UC3827-1, UC3827-2

www.ti.com

SLUS365D –APRIL 1999– REVISED APRIL 2011

BUCK CURRENT/VOLTAGE FED PUSH-PULL

PWM CONTROLLERS

Check for Samples: UC2827-1, UC2827-2, UC3827-1, UC3827-2

FEATURES

DESCRIPTION

• Ideal for Multiple Output and/or High

The UC3827 family of controller devices provides an

Voltage Output Voltage Converters

integrated control solution for cascaded buck and

• Up to 500 kHz Operation

push-pull converters. These converters are known as

• High Voltage, High Current Floating

current fed or voltage fed push-pull converters and

Driver for Buck Converter Stage

are ideally suited for multiple output and/or high

voltage output applications. In both current fed and

• UC3827-1 Current Fed Controller has

voltage fed modes, the push-pull switches are driven

Push-Pull Drivers with Overlapping

at 50% nominal duty cycles and at one half the

Conduction Periods

switching frequency of the buck stage. In the current

• UC3827-2 Voltage Fed Controller has

fed mode, the two switches are driven with a

Push-Pull Drivers with Nonoverlapping

specified over-lap period to prevent ringing and

Conduction Periods

voltage stress on the devices. In the voltage fed

mode, the two switches are driven with a specified

• Average Current Mode, Peak Current

gap time between the switches to prevent shorting

Mode or Voltage Mode with Input

the transformer across the energy storage capacitor

Voltage Feedforward Control for Buck

and to prohibit excessive currents flowing through the

Power Stage

devices.

• Wide Bandwidth, Low Offset,

The converter's output voltage is regulated by pulse

Differential Current Sense Amplifier

width modulation of the buck switch. The UC3827

• Precise Short Circuit Current Control

contains complete protection and PWM control

functions for the buck converter. Easy control of the

floating switch is accomplished by the floating drive

circuitry. The gate drive waveform is level shifted to

support an input voltage up to 72 V

BLOCK DIAGRAM

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.

Summary of content (16 pages)

PAGE 1
UC2827-1, UC2827-2 UC3827-1, UC3827-2 SLUS365D – APRIL 1999 – REVISED APRIL 2011 www.ti.
PAGE 2
UC2827-1, UC2827-2 UC3827-1, UC3827-2 SLUS365D – APRIL 1999 – REVISED APRIL 2011 www.ti.com DESCRIPTION (CONTINUED) The UC3827 can be set up in traditional voltage mode control using input voltage feedforward technique or in current mode control. Using current mode control prevents potential core saturation of the push-pull transformer due to mismatches in timing and in component tolerances.
PAGE 3
UC2827-1, UC2827-2 UC3827-1, UC3827-2 SLUS365D – APRIL 1999 – REVISED APRIL 2011 www.ti.com ABSOLUTE MAXIMUM RATINGS (1) UC2827-1 UC2827-2 UC3827-1 UC3827-2 Supply voltage, VCC 20 CEAO, CEA+, CEA-, CSAO, CSA+, CSA-, CT, DELAY, PUSH, PULL, RAMP, RT, SS, SYNC, VEA+, VEAO, Input voltage range –0.3 to 5 V+ and BUCK 90-VCC ±250 mA ±1 A I/O continuous ±200 mA I/O peak ±0.
PAGE 4
UC2827-1, UC2827-2 UC3827-1, UC3827-2 SLUS365D – APRIL 1999 – REVISED APRIL 2011 www.ti.com ELECTRICAL CHARACTERISTICS (continued) Unless otherwise spsecified, VVCC = 15 V, VV+ = 14.3 V, CCT = 340 pF, RRT = 10 kΩ, RDELAY = 24.
PAGE 5
UC2827-1, UC2827-2 UC3827-1, UC3827-2 SLUS365D – APRIL 1999 – REVISED APRIL 2011 www.ti.
PAGE 6
UC2827-1, UC2827-2 UC3827-1, UC3827-2 SLUS365D – APRIL 1999 – REVISED APRIL 2011 www.ti.com Terminal Functions (continued) TERMINAL NAME PUSH N or DW Q 24 28 I/O DESCRIPTION O Ground referenced output to drive an N-channel MOSFET. The PULL and the PUSH outputs are driving the two switches of the push-pull converter with complementary signals at close to a 50% duty cycle. Any undervoltage faults disables PUSH to an off condition (low).
PAGE 7
UC2827-1, UC2827-2 UC3827-1, UC3827-2 SLUS365D – APRIL 1999 – REVISED APRIL 2011 www.ti.com APPLICATION INFORMATION VREF RT 2.5 V – + RT CT OSCILLATOR VREF 1.4 V 2.5 V 2.9 V CT S R SYNC 0.5 V 10 kW VDG−99086 Figure 1. Oscillator Block With External Connections CIRCUIT BLOCK DESCRIPTION PWM Oscillator The oscillator block diagram with external connections is shown in Equation 1. A resistor (RT) connected to pin RT sets the linear charge current: I RT + 2.
PAGE 8
UC2827-1, UC2827-2 UC3827-1, UC3827-2 SLUS365D – APRIL 1999 – REVISED APRIL 2011 www.ti.com VAO Current Command Charging Discharging OSC 2.9 V 0.5 V THRESHOLD 3.6 V 1.4 V Threshold CLKSYN 8.5 V OUT 0V VDG−99087 Figure 2. Oscillator and PWM Output Waveform OSC2 OSC3 SYNC SYNC SYNC 100 pF 100 pF 100 pF CLKSYN BUS OSC1 100 pF OSC10 SYNC 10 kW VDG−99085 Figure 3.
PAGE 9
PACKAGE OPTION ADDENDUM www.ti.
PAGE 10
PACKAGE OPTION ADDENDUM www.ti.com 31-Oct-2013 (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined.
PAGE 11
PACKAGE MATERIALS INFORMATION www.ti.com 15-Jan-2014 TAPE AND REEL INFORMATION *All dimensions are nominal Device UC2827DWTR-1 Package Package Pins Type Drawing SOIC DW 24 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 2000 330.0 24.4 Pack Materials-Page 1 10.75 B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 15.7 2.7 12.0 24.
PAGE 12
PACKAGE MATERIALS INFORMATION www.ti.com 15-Jan-2014 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) UC2827DWTR-1 SOIC DW 24 2000 367.0 367.0 45.
PAGE 13
MECHANICAL DATA MPDI006B – SEPTEMBER 2001 – REVISED APRIL 2002 N (R–PDIP–T24) PLASTIC DUAL–IN–LINE 1.222 (31,04) MAX 24 13 0.360 (9,14) MAX 1 12 0.070 (1,78) MAX 0.200 (5,08) MAX 0.425 (10,80) MAX 0.020 (0,51) MIN Seating Plane 0.125 (3,18) MIN 0.100 (2,54) 0’–15’ 0.021 (0,53) 0.015 (0,38) 0.010 (0,25) 0.010 (0,25) NOM 4040051–3/D 09/01 NOTES: A. All linear dimensions are in inches (millimeters). B. This drawing is subject to change without notice. C.
PAGE 14
PAGE 15
PAGE 16
IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.