Datasheet

TPS40140
SLUS660H –SEPTEMBER 2005–REVISED JUNE 2013 www.ti.com
6.4 ABBREVIATIONS
Table 6-4. Definition of Symbols
SYMBOL DESCRIPTION
V
IN(min)
Minimum Operating Input voltage
V
IN(max)
Maximum Operating Input Voltage
V
OUT
Output Voltage
I
RIPPLE
Inductor Peak-Peak Ripple Current
I
TRAN(MAX)
Maximum Load Transient
V
UNDER
Output Voltage Undershot
V
OVER
Output Voltage Overshot
V
RIPPLE(TotOUT)
Total Output Ripple
V
RIPPLE(COUT)
Output Voltage Ripple Due to Output Capacitance
V
RIPPLE(CIN)
Input Voltage Ripple Due to Input Capacitance
V
RIPPLE(CinESR)
Input Voltage Ripple Due to the ESR of Input Capacitance
Psw
cond
High Side MOSFET Conduction Loss
Isw
rms
RMS Current in the High Side MOSFET
Rdson(sw) ON Drain-Source Resistance of the High Side MOSFET
Psw
sw
High Side MOSFET Switching Loss
Ipk Peak Current Through the High Side MOSFET
R
drv
Driver Resistance of the High Side MOSFET
Qgd
sw
Gate to Drain Charge of the High Side MOSFET
Qgs
sw
Gate to Source Charge of the High Side MOSFET
Vgsw Gate Drive Voltage of the High Side MOSFET
Psw
gate
Gate Drive Loss of the High Side MOSFET
Qg
sw
Gate Charge of the High Side MOSFET
Psw
tot
Total Losses of the High Side MOSFET
Psr
cond
Low Side MOSFET Conduction Loss
Isr
rms
RMS Current in the Low Side MOSFET
Rdson(sr) ON Drain-Source Resistance of the low Side MOSFET
Psr
gate
Gate Drive Loss of the Low Side MOSFET
Qg
sr
Gate Charge of the Low Side MOSFET
Vgsr Gate Drive Voltage of the Low Side MOSFET
P
diode
Power Loss in the Diode
t
d
Dead Time Between the Conduction of High and Low Side MOSFET
V
f
Forward Voltage Drop of the Body Diode of the Low Side MOSFET
Psr
tot
Total Losses of the Low Side MOSFET
DCR Inductor DC Resistance
Ac The Gain of the Current Sensing Amplifier, typically it is 13
R
OUT
Output Load Resistance
V
ramp
Ramp Amplitude, typically it is 0.5V
T Switching Period
Gvc(s) Control to Output Transfer Function
Gc(s) Compensator Transfer Function
Tv(s) Loop Gain Transfer Function
Acm Gain of the Compensator
f
p
The Pole Frequency of the Compensator
f
z
The Zero Frequency of the Compensator
60 DESIGN EXAMPLES Copyright © 2005–2013, Texas Instruments Incorporated
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