Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - AC/DC converter, offline switcher Flyback SOT 23 6

UCC28700, UCC28701

UCC28702, UCC28703

www.ti.com

SLUSB41 – JULY 2012

Constant-Voltage, Constant-Current Controller

With Primary-Side Regulation

Check for Samples: UCC28700, UCC28701, UCC28702, UCC28703

FEATURES

DESCRIPTION

The UCC28700 family of flyback power supply

• < 30-mW No-Load Power for 5-Star Rating

controllers provides Constant-Voltage (CV) and

• Primary-Side Regulation (PSR) Eliminates

Constant-Current (CC) output regulation without the

Opto-Coupler

use of an optical coupler. The devices process

• ±5% Voltage and Current Regulation

information from the primary power switch and an

auxiliary flyback winding for precise control of output

• 130-kHz Maximum Switching Frequency

voltage and current. Low start-up current,

Enables High-Power Density Charger Designs

dynamically-controlled operating states and a tailored

• Quasi-Resonant Valley-Switching Operation

modulation profile support very low stand-by power

for Highest Overall Efficiency

without sacrificing start-up time or output transient

response.

• Patent-Pending Frequency-Jitter Scheme to

Ease EMI Compliance

Control algorithms in the UCC28700 family allow

• Wide VDD Range Allows Small Bias Capacitor

operating efficiencies to meet or exceed applicable

standards. The output drive interfaces to a MOSFET

• Clamped Gate-Drive Output for MOSFET

power switch. Discontinuous Conduction Mode

• Protection Functions: Over-Voltage, Low-Line,

(DCM) with valley switching reduces switching losses.

and Over-Current

Modulation of switching frequency and primary

• Programmable Cable Compensation

current peak amplitude (FM and AM) keeps the

conversion efficiency high across the entire load and

(UCC28700 only)

line ranges.

• NTC Resistor Interface (UCC28701, UCC28702

and UCC28703 only) with Fixed Cable

The controllers have a maximum switching frequency

Compensation Options

of 130 kHz and always maintain control of the peak-

primary current in the transformer. Protection features

• SOT23-6 Package

help keep primary and secondary component

stresses in check. The UCC28700 allows the level of

APPLICATIONS

cable compensation to be programmed. The

• USB-Compliant Adapters and Chargers for

UCC28701, UCC28702 and UCC28703 devices allow

remote temperature sensing using a Negative

Consumer Electronics (cell phones, tablets

Temperature Coefficient (NTC) resistor while

and cameras)

providing fixed cable-compensation levels.

• AC and DC Power Supplies

Simplified Application Diagram and Typical V-I Regulation

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 (31 pages)

PAGE 1
UCC28700, UCC28701 UCC28702, UCC28703 www.ti.com SLUSB41 – JULY 2012 Constant-Voltage, Constant-Current Controller With Primary-Side Regulation Check for Samples: UCC28700, UCC28701, UCC28702, UCC28703 FEATURES DESCRIPTION • • The UCC28700 family of flyback power supply controllers provides Constant-Voltage (CV) and Constant-Current (CC) output regulation without the use of an optical coupler.
PAGE 2
UCC28700, UCC28701 UCC28702, UCC28703 SLUSB41 – JULY 2012 www.ti.com Table 1. PRODUCT INFORMATION (1) (2) PART NUMBER PACKAGED DEVICES UCC28700 UCC28701 SOT23 6-Pin (DBV) UCC28702 UCC28703 (1) (2) VERSION Programmable cable compensation NTC, 0 mV (at 5-V output) cable compensation option NTC, 150 mV (at 5-V output) cable compensation option NTC, 300 mV (at 5-V output) cable compensation option See Addendum for specific device ordering information.
PAGE 3
UCC28700, UCC28701 UCC28702, UCC28703 www.ti.com SLUSB41 – JULY 2012 RECOMMENDED OPERATING CONDITIONS over operating free-air temperature range (unless otherwise noted) MIN TYP MAX UNIT VDD Bias supply operating voltage CVDD VDD bypass capacitor 9 35 V 0.
PAGE 4
UCC28700, UCC28701 UCC28702, UCC28703 SLUSB41 – JULY 2012 www.ti.com ELECTRICAL CHARACTERISTICS over operating free-air temperature range, VDD = 25 V, RCBC = RNTC = open, -20°C ≤ TA ≤ 125°C, TJ = TA (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNITS Bias Supply Input IRUN Supply current, run IDRV = 0, run state 2.1 2.65 IWAIT Supply current, wait IDRV = 0, wait state 85 110 ISTART Supply current, start IDRV = 0, VVDD = 18 V, start state 1.0 1.
PAGE 5
UCC28700, UCC28701 UCC28702, UCC28703 www.ti.com SLUSB41 – JULY 2012 ELECTRICAL CHARACTERISTICS (continued) over operating free-air temperature range, VDD = 25 V, RCBC = RNTC = open, -20°C ≤ TA ≤ 125°C, TJ = TA (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNITS Protection VOVP Over-voltage threshold At VS input, TJ = 25°C 4.52 4.6 4.68 VOCP Over-current threshold At CS input 1.4 1.5 1.
PAGE 6
UCC28700, UCC28701 UCC28702, UCC28703 SLUSB41 – JULY 2012 www.ti.
PAGE 7
UCC28700, UCC28701 UCC28702, UCC28703 www.ti.com SLUSB41 – JULY 2012 DBV Package (Top View) CBC (00) NTC (01) 1 6 VS VDD 2 5 GND DRV 3 4 CS Table 2. TERMINAL FUNCTIONS PIN DESCRIPTION NAME NO. I/O CBC (UCC28700) 1 I CaBle Compensation is a programming pin for compensation of cable voltage drop. Cable compensation is programmed with a resistor to GND. CS 4 I Current Sense input connects to a ground-referenced current-sense resistor in series with the power switch.
PAGE 8
UCC28700, UCC28701 UCC28702, UCC28703 SLUSB41 – JULY 2012 www.ti.com Detailed Pin Description VDD (Device Bias Voltage Supply): The VDD pin is connected to a bypass capacitor to ground and a start-up resistance to the input bulk capacitor (+) terminal. The VDD turn-on UVLO threshold is 21 V and turn-off UVLO threshold is 8.1 V, with an available operating range up to 35 V.
PAGE 9
UCC28700, UCC28701 UCC28702, UCC28703 www.ti.com SLUSB41 – JULY 2012 CS (Current Sense): The current-sense pin is connected through a series resistor (RLC) to the current-sense resistor (RCS). The current-sense threshold is 0.75 V for IPP(max) and 0.25 V for IPP(min). The series resistor RLC provides the function of feed-forward line compensation to eliminate change in IPP due to change in di/dt and the propagation delay of the internal comparator and MOSFET turn-off time.
PAGE 10
UCC28700, UCC28701 UCC28702, UCC28703 SLUSB41 – JULY 2012 www.ti.com TYPICAL CHARACTERISTICS At VDD = 25 V, unless otherwise noted. 10 10 Run State IRUN, VDD = 25 V 1 IVDD − Bias Supply Current (mA) IVDD − Bias Supply Current (mA) 1 Wait State 0.1 0.01 VDD Turn−Off 0.001 VDD Turn−On IWAIT, VDD = 25 V 0.1 0.01 0.001 0.0001 ISTART, VDD = 18 V Start State 0.00001 0 5 10 15 20 25 VDD − Bias Supply Voltage (V) 30 35 0.0001 −25 0 25 50 75 TJ − Temperature (°C) 100 G001 G002 Figure 1.
PAGE 11
UCC28700, UCC28701 UCC28702, UCC28703 www.ti.com SLUSB41 – JULY 2012 TYPICAL CHARACTERISTICS (continued) At VDD = 25 V, unless otherwise noted. 330 VCCR − Constant Current Regulating Level (mV) VCSTMIN − Minimum CS Threshold Voltage (mV) 270 265 260 255 250 245 240 235 230 −25 0 25 50 75 TJ − Temperature (°C) 100 325 320 315 310 −25 125 0 25 50 75 TJ − Temperature (°C) 100 G005 125 G006 Figure 5. Minimum CS Threshold Voltage vs. Temperature Figure 6. Constant-Current Regulating Level vs.
PAGE 12
UCC28700, UCC28701 UCC28702, UCC28703 SLUSB41 – JULY 2012 www.ti.com TYPICAL CHARACTERISTICS (continued) At VDD = 25 V, unless otherwise noted. 120 115 0.98 INTC −NTC Pull−up Current (µA) VNTCTH − NTC Shutdown Threshold Voltage (V) 1.00 0.96 0.94 0.92 110 105 100 95 0.90 −25 0 25 50 75 TJ − Temperature (°C) 100 125 90 −25 0 25 50 75 TJ − Temperature (°C) 100 G009 Figure 9. NTC Shut-down Threshold Voltage vs. Temperature 125 G010 Figure 10. NTC Pull-Up Current vs. Temperature 4.
PAGE 13
UCC28700, UCC28701 UCC28702, UCC28703 www.ti.com SLUSB41 – JULY 2012 FUNCTIONAL DESCRIPTION The UCC28700 is a flyback power supply controller which provides accurate voltage and constant current regulation with primary-side feedback, eliminating the need for opto-coupler feedback circuits. The controller operates in discontinuous conduction mode with valley-switching to minimize switching losses.
PAGE 14
UCC28700, UCC28701 UCC28702, UCC28703 SLUSB41 – JULY 2012 www.ti.com The UCC28700 VS signal sampler includes signal discrimination methods to ensure an accurate sample of the output voltage from the auxiliary winding. There are however some details of the auxiliary winding signal to ensure reliable operation, specifically the reset time of the leakage inductance and the duration of any subsequent leakage inductance ring.
PAGE 15
UCC28700, UCC28701 UCC28702, UCC28703 www.ti.com SLUSB41 – JULY 2012 Primary-Side Current Regulation Timing information at the VS pin and current information at the CS pin allow accurate regulation of the secondary average current. The control law dictates that as power is increased in CV regulation and approaching CC regulation the primary-peak current is at IPP(max).
PAGE 16
UCC28700, UCC28701 UCC28702, UCC28703 SLUSB41 – JULY 2012 www.ti.com Valley-Switching The UCC28700 utilizes valley-switching to reduce switching losses in the MOSFET, to reduce induced-EMI, and to minimize the turn-on current spike at the sense resistor. The controller operates in valley-switching in all load conditions unless the VDS ringing has diminished.
PAGE 17
UCC28700, UCC28701 UCC28702, UCC28703 www.ti.com SLUSB41 – JULY 2012 Fault Protection There is comprehensive fault protection incorporated into the UCC28700. Protection functions include: • Output over voltage • Input under voltage • Internal over temperature • Primary over-current fault • CS pin fault • VS pin fault A UVLO reset and restart sequence applies for all fault protection events. The output over-voltage function is determined by the voltage feedback on the VS pin.
PAGE 18
UCC28700, UCC28701 UCC28702, UCC28703 SLUSB41 – JULY 2012 www.ti.com DESIGN PROCEDURE This procedure outlines the steps to design a constant-voltage, constant-current flyback converter using the UCC28700 family of controllers. Refer to the Figure 19 for component names and network locations. The design procedure equations use terms that are defined below. Figure 19. Design Procedure Application Example Definition of Terms Capacitance Terms in Farads • CBULK: total input capacitance of CB1 and CB2.
PAGE 19
UCC28700, UCC28701 UCC28702, UCC28703 www.ti.com SLUSB41 – JULY 2012 Current and Voltage Scaling Terms • KAM: maximum-to-minimum peak primary current ratio (see ELECTRICAL CHARACTERISTICS). • KLC: current-scaling constant (see ELECTRICAL CHARACTERISTICS). Transformer Terms • LP: transformer primary inductance. • NAS: transformer auxiliary-to-secondary turns ratio. • NPA: transformer primary-to-auxiliary turns ratio. • NPS: transformer primary-to-secondary turns ratio.
PAGE 20
UCC28700, UCC28701 UCC28702, UCC28703 SLUSB41 – JULY 2012 www.ti.com Voltage Terms in Volts • VBLK: highest bulk capacitor voltage for stand-by power measurement. • VBULK(min): minimum voltage on CB1 and CB2 at full power. • VOCBC: target cable compensation voltage at the output terminals. • VCBC(max): maximum voltage at the CBC pin at the maximum converter output current (see ELECTRICAL CHARACTERISTICS). • VCCR: constant-current regulating voltage (see ELECTRICAL CHARACTERISTICS).
PAGE 21
UCC28700, UCC28701 UCC28702, UCC28703 www.ti.com SLUSB41 – JULY 2012 Stand-by Power Estimate Assuming no-load stand-by power is a critical design parameter, determine estimated no-load power based on target converter maximum switching frequency and output power rating. The following equation estimates the stand-by power of the converter. (7) For a typical USB charger application, the bias power during no-load is approximately 2.5 mW. This is based on 25-V VDD and 100-µA bias current.
PAGE 22
UCC28700, UCC28701 UCC28702, UCC28703 SLUSB41 – JULY 2012 www.ti.com Transformer Turns Ratio, Inductance, Primary-Peak Current The maximum primary-to-secondary turns ratio can be determined by the target maximum switching frequency at full load, the minimum input capacitor bulk voltage, and the estimated DCM quasi-resonant time. Initially determine the maximum available total duty cycle of the on time and secondary conduction time based on target switching frequency and DCM resonant time.
PAGE 23
UCC28700, UCC28701 UCC28702, UCC28703 www.ti.com SLUSB41 – JULY 2012 Transformer Parameter Verification The transformer turns ratio selected affects the MOSFET VDS and secondary rectifier reverse voltage so these should be reviewed. The UCC28700 controller requires a minimum on time of the MOSFET (TON) and minimum DMAG time (TDMAG) of the secondary rectifier in the high line, minimum load condition. The selection of FMAX, LP and RCS affects the minimum TON and TDMAG.
PAGE 24
UCC28700, UCC28701 UCC28702, UCC28703 SLUSB41 – JULY 2012 www.ti.com VDD Capacitance, CDD The capacitance on VDD needs to supply the device operating current until the output of the converter reaches the target minimum operating voltage in constant-current regulation. At this time the auxiliary winding can sustain the voltage to the UCC28700. The total output current available to the load and to charge the output capacitors is the constant-current regulation target.
PAGE 25
PACKAGE OPTION ADDENDUM www.ti.
PAGE 26
PACKAGE OPTION ADDENDUM www.ti.com (4) 27-Jul-2013 There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device.
PAGE 27
PACKAGE MATERIALS INFORMATION www.ti.com 6-Dec-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) UCC28700DBVR SOT-23 DBV 6 3000 178.0 9.0 B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 3.23 3.17 1.37 4.0 8.0 Q3 UCC28700DBVT SOT-23 DBV 6 250 178.0 9.0 3.23 3.17 1.37 4.0 8.0 Q3 UCC28701DBVR SOT-23 DBV 6 3000 178.0 9.0 3.23 3.17 1.37 4.0 8.
PAGE 28
PACKAGE MATERIALS INFORMATION www.ti.com 6-Dec-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) UCC28700DBVR SOT-23 DBV 6 3000 180.0 180.0 18.0 UCC28700DBVT SOT-23 DBV 6 250 180.0 180.0 18.0 UCC28701DBVR SOT-23 DBV 6 3000 180.0 180.0 18.0 UCC28701DBVT SOT-23 DBV 6 250 180.0 180.0 18.0 UCC28702DBVR SOT-23 DBV 6 3000 180.0 180.0 18.0 UCC28703DBVR SOT-23 DBV 6 3000 180.0 180.0 18.
PAGE 29
PAGE 30
PAGE 31
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.