UCC28700_15 Datasheet, PDF (26/35 Pages) Texas Instruments – UCC2870x Constant-Voltage, Constant-Current Controller With Primary-Side Regulation

UCC28700, UCC28701, UCC28702, UCC28703
SLUSB41A – JULY 2012 – REVISED DECEMBER 2014
www.ti.com
Device Support (continued)
12.1.1.4 Current Terms in Amperes
I_OCC
I_PP(max)
I_START
I_TRAN
I_VSL(run)
converter output constant-current target.
maximum transformer primary current.
start-up bias supply current (see the Electrical Characteristics table).
required positive load-step current.
VS pin run current (see the Electrical Characteristics table).
12.1.1.5 Current and Voltage Scaling Terms
K_AM
maximum-to-minimum peak primary current ratio (see the Electrical Characteristics table).
K_LC
current-scaling constant (see the Electrical Characteristics table).
12.1.1.6 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.
12.1.1.7 Power Terms in Watts
P_IN
P_OUT
P_RSTR
P_SB
P_{SB_CONV}
converter maximum input power.
full-load output power of the converter.
VDD start-up resistor power dissipation.
total stand-by power.
P_SB minus start-up resistor and snubber losses.
12.1.1.8 Resistance Terms in Ω
R_CS
R_ESR
R_PL
R_S1
R_S2
R_STR
R_STR
primary current programming resistance
total ESR of the output capacitor(s).
preload resistance on the output of the converter.
high-side VS pin resistance.
low-side VS pin resistance.
maximum start-up resistance to achieve the turn-on time target.
V_DD start-up resistance.
12.1.1.9 Timing Terms in Seconds
T_D
T_DMAG(min)
T_ON(min)
T_R
T_STR
current-sense delay including MOSFET turn-off delay; add 50 ns to MOSFET delay.
minimum secondary rectifier conduction time.
minimum MOSFET on time.
resonant frequency during the DCM (discontinuous conduction mode) time.
converter start-up time requirement.
12.1.1.10 Voltage Terms in Volts
V_BLK
highest bulk capacitor voltage for stand-by power measurement.
26
Submit Documentation Feedback
Copyright © 2012–2014, Texas Instruments Incorporated
Product Folder Links: UCC28700 UCC28701 UCC28702 UCC28703