12 Device and Documentation Support
12.1 Device Support
12.1.1 Device Nomenclature
18.104.22.168 Capacitance Terms in Farads
CBULKtotal input capacitance of CB1 and CB2.
CDDminimum required capacitance on the VDD pin.
COUTminimum output capacitance required.
22.214.171.124 Duty Cycle Terms
DMAGCCsecondary diode conduction duty cycle in CC, 0.425.
DMAXMOSFET on-time duty cycle.
126.96.36.199 Frequency Terms in Hertz
fLINEminimum line frequency.
fMAXtarget full-load maximum switching frequency of the converter.
fMINminimum switching frequency of the converter, add 15% margin over the fSW(min) limit of the device.
fSW(min)minimum switching frequency (see the Electrical Characteristics table)
188.8.131.52 Current Terms in Amperes
IOCCconverter output constant-current target.
IPP(max)maximum transformer primary current.
ISTART start-up bias supply current (see the Electrical Characteristics table).
ITRANrequired positive load-step current.
IVSL(run)VS pin run current (see the Electrical Characteristics table).
184.108.40.206 Current and Voltage Scaling Terms
220.127.116.11 Transformer Terms
LPtransformer primary inductance.
NAStransformer auxiliary-to-secondary turns ratio.
NPAtransformer primary-to-auxiliary turns ratio.
NPStransformer primary-to-secondary turns ratio.
18.104.22.168 Power Terms in Watts
PINconverter maximum input power.
POUTfull-load output power of the converter.
PRSTRVDD start-up resistor power dissipation.
PSB_CONVPSB minus start-up resistor and snubber losses.
22.214.171.124 Resistance Terms in Ω
RCSprimary current programming resistance
RESRtotal ESR of the output capacitor(s).
RPLpreload resistance on the output of the converter.
RS1high-side VS pin resistance.
RS2low-side VS pin resistance.
RSTRmaximum start-up resistance to achieve the turn-on time target.
RSTRVDD start-up resistance.
126.96.36.199 Timing Terms in Seconds
TDcurrent-sense delay including MOSFET turn-off delay; add 50 ns to MOSFET delay.
TDMAG(min)minimum secondary rectifier conduction time.
TON(min)minimum MOSFET on time.
TRresonant frequency during the DCM (discontinuous conduction mode) time.
TSTRconverter start-up time requirement.
188.8.131.52 Voltage Terms in Volts
VBLKhighest bulk capacitor voltage for stand-by power measurement.
VBULK(min)minimum voltage on CB1 and CB2 at full power.
VOCBCtarget cable compensation voltage at the output terminals.
VCBC(max)maximum voltage at the CBC pin at the maximum converter output current (see the Electrical Characteristics table).
VCCRconstant-current regulating voltage (see the Electrical Characteristics table).
VCST(max)CS pin maximum current-sense threshold (see the Electrical Characteristics table).
VCST(min)CS pin minimum current-sense threshold (see the Electrical Characteristics table).
VDD(off)UVLO turn-off voltage (see the Electrical Characteristics table).
VDD(on)UVLO turn-on voltage (see the Electrical Characteristics table).
VOΔoutput voltage drop allowed during the load-step transient.
VDSPKpeak MOSFET drain-to-source voltage at high line.
VFsecondary rectifier forward voltage drop at near-zero current.
VFAauxiliary rectifier forward voltage drop.
VLKestimated leakage inductance energy reset voltage.
VOCVregulated output voltage of the converter.
VOCCtarget lowest converter output voltage in constant-current regulation.
VREVpeak reverse voltage on the secondary rectifier.
VRIPPLEoutput peak-to-peak ripple voltage at full-load.
VVSRCV regulating level at the VS input (see the Electrical Characteristics table).
184.108.40.206 AC Voltage Terms in VRMS
VIN(max)maximum input voltage to the converter.
VIN(min)minimum input voltage to the converter.
VIN(run)converter input start-up (run) voltage.
220.127.116.11 Efficiency Terms
ηSBestimated efficiency of the converter at no-load condition, not including start-up resistance or bias losses. For a 5-V USB charger application, 60% to 65% is a good initial estimate.
ηconverter overall efficiency.
ηXFMRtransformer primary-to-secondary power transfer efficiency.
12.2 Documentation Support
12.2.1 Related Documentation
For related documentation see the following:
Using the UCC28700EVM-068, Evaluation Module, SLUU968
12.2.2 Related Links
The table below lists quick access links. Categories include technical documents, support and community resources, tools and software, and quick access to sample or buy.
All other trademarks are the property of their respective owners.
12.4 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.