11.1.1.1.1 Capacitance Terms in Farads

• C_BULK: total input capacitance of C_B1 and C_B2.
• C_DD: minimum required capacitance on the VDD pin.
• C_OUT: minimum output capacitance required.

11.1.1.1.2 Duty Cycle Terms

• D_MAGCC: secondary diode conduction duty cycle in CC, 0.425.
• D_MAX: transistor on-time duty cycle.

11.1.1.1.3 Frequency Terms in Hertz

• f_LINE: minimum line frequency.
• f_MAX: target full-load maximum switching frequency of the converter.
• f_MIN: minimum switching frequency of the converter, add 15% margin over the f_SW(min) limit of the device.
• f_SW(min): minimum switching frequency (see Electrical Characteristics).

11.1.1.1.4 Current Terms in Amperes

• I_OCC: converter output constant-current target.
• I_PP(max): maximum transformer primary current.
• I_START: start-up bias supply current (see Electrical Characteristics).
• I_TRAN : required positive load-step current.
• I_VSL(run): VS pin run current (see Electrical Characteristics).

• I_DRS: Driver source current (see Electrical Characteristics).

11.1.1.1.5 Current and Voltage Scaling Terms

• K_AM: maximum-to-minimum peak primary current ratio (see Electrical Characteristics).
• K_LC: current-scaling constant (see Electrical Characteristics).

11.1.1.1.6 Transformer Terms

• L_P: transformer primary inductance.
• N_AS: transformer auxiliary-to-secondary turns ratio.
• N_PA: transformer primary-to-auxiliary turns ratio.
• N_PS: transformer primary-to-secondary turns ratio.

11.1.1.1.7 Power Terms in Watts

• P_IN: converter maximum input power.
• P_OUT: full-load output power of the converter.
• P_RSTR: VDD start-up resistor power dissipation.
• P_SB: total stand-by power.
• P_{SB_CONV}: P_SB minus start-up resistor and snubber losses.

11.1.1.1.8 Resistance Terms in Ω

• R_CS: primary current programming resistance.
• R_ESR: total ESR of the output capacitor(s).
• R_PL: preload resistance on the output of the converter.
• R_S1: high-side VS pin resistance.
• R_S2: low-side VS pin resistance.
• R_STR : startup resistance.

11.1.1.1.9 Timing Terms in Seconds

• t_D: current-sense delay including transistor turnoff delay; add 50 ns to transistor delay.
• t_DMAG(min): minimum secondary rectifier conduction time.
• t_ON(min): minimum transistor on time.
• t_R: resonant frequency during the DCM (discontinuous conduction mode) time.
• t_ST: startup time

11.1.1.1.10 Voltage Terms in Volts

• V_BLK: highest bulk capacitor voltage for stand-by power measurement.
• V_BULK(min): minimum voltage on C_B1 and C_B2 at full power.
• V_OCBC: target cable compensation voltage at the output terminals.
• V_CBC(max): maximum voltage at the CBC pin at the maximum converter output current (see Electrical Characteristics).
• V_CCR: constant-current regulating voltage (see Electrical Characteristics).
• V_CST(max): CS pin maximum current-sense threshold (see Electrical Characteristics).
• V_CST(min): CS pin minimum current-sense threshold (see Electrical Characteristics).
• V_DD(off): UVLO turnoff voltage (see Electrical Characteristics).
• V_DD(on): UVLO turnon voltage (see Electrical Characteristics).
• V_OΔ: output voltage drop allowed during the load-step transient.
• V_CPK: peak transistor collector to emitter voltage at high line.
• V_F: secondary rectifier forward voltage drop at near-zero current.
• V_FA: auxiliary rectifier forward voltage drop.
• V_LK: estimated leakage inductance energy reset voltage.
• V_OCV: regulated output voltage of the converter.
• V_OCC: target lowest converter output voltage in constant-current regulation.
• V_REV: peak reverse voltage on the secondary rectifier.
• V_RIPPLE: output peak-to-peak ripple voltage at full-load.
• V_VSR: CV regulating level at the VS input (see Electrical Characteristics).

11.1.1.1.11 AC Voltage Terms in V_RMS

• V_IN(max): maximum input voltage to the converter.
• V_IN(min): minimum input voltage to the converter.
• V_IN(run): converter input start-up (run) voltage.

11.1.1.1.12 Efficiency Terms

• η_SB: estimated efficiency of the converter at no-load condition, not including start-up resistance or bias losses. η_SB: For a 5-V USB charger application, 60% to 65% is a good initial estimate.
• η: converter overall efficiency.
• η_XFMR: transformer primary-to-secondary power transfer efficiency.